Wikipedia:Featured article candidates/Amphetamine/archive1

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The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was not promoted by GrahamColm 10:01, 22 January 2014 (UTC) [1].[reply]

Amphetamine[edit]

Amphetamine (edit | talk | history | links | watch | logs)

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Nominator(s): Seppi333 (Insert 2¢) 21:49, 6 December 2013 (UTC)[reply]

I'm sure everyone recognizes the article title. :)

I’m nominating this article for FA because, after spending a couple hundred hours researching this compound with the research tools at my university, and six months editing the article, I’m fairly certain it’s the most comprehensive source of information currently available on amphetamine in humans. Moreover, the article received an extremely rigorous GA review by Sasata to help prepare the article for this FA review, along with constant input from WP-MED and WP-PHARM. Consequently, I feel the article is now prepared to go through this process. I really enjoyed (re-)writing it, so I hope you enjoy reading it. Seppi333 (Insert 2¢) 21:49, 6 December 2013 (UTC)[reply]

Figured I should mention this here - I made substantive additions to Amphetamine#Medical and Amphetamine#Dependence, addiction, and withdrawal over the last few days; I used most of those refs in methamphetamine while revamping it for GA. Seppi333 (Insert 2¢) 07:59, 4 January 2014 (UTC)[reply]

Aa77zz[edit]

Oppose - although it is clear that a great deal of effort has been put into this article, it currently doesn't meet the FA criteria.

  • Why are there so many citations in the lead? This isn't necessary and makes the text cluttered and more difficult to read. See MOS:LEADCITE.
  • There are links to common words such as: pharmaceutical, depression, obesity, euphoria, libido, arousal, reaction time. See WP:OVERLINK. In particular the lead is a sea of blue - see WP:LEADLINK
Some of those terms might be considered jargon by some readers. I did not think this article suffers from overlinking personally. Providing an explanation for any potentially confusing terms is more important that the overall amount of links. Lesion (talk) 14:31, 13 December 2013 (UTC)[reply]
  • Why is it necessary to quote great chucks of text in the References? See citations 9, 12, 13 etc.
  • Why are 3 or 4 citations used for uncontroversial statements? In most cases a single appropriate authoritative review should be sufficient.
  • The text contains sentences with long lists. This cannot be considered as good English. Examples: "A number of substances have been shown to produce amphetamine as a metabolite, including amphetaminil, benzphetamine, clobenzorex, dimethylamphetamine, ethylamphetamine, famprofazone, fencamine, fenethylline, fenproporex, furfenorex, lisdexamfetamine, mefenorex, mesocarb, methamphetamine, prenylamine, propylamphetamine, and selegiline, among others." and "...these side effects can include abdominal pain, acne, arrhythmias, blurred vision, bruxism, constipation or diarrhea, diaphoresis, dry skin, dry mouth, erectile dysfunction, fever, headache, hypertension or hypotension from a vasovagal response, indigestion, insomnia, loss of appetite, nausea, pallor, palpitations, Raynaud's phenomenon (secondary), reduced seizure threshold, tachycardia, tachypnea, tics, vomiting, and weight loss."
  • The article appears to have only one sentence on the different pharmacology of the stereoisomers: "As a CNS stimulant,..." - (with a weak PubChem citation). I'm surprised that there is so little - aren't there review articles on this?
  • Note 5 " The study specified the EMIT II Plus Monoclonal Amphetamine/Metamphetamine assay." is just jargon and is not appropriate in an general article, even in a note.

Aa77zz (talk) 12:46, 7 December 2013 (UTC)[reply]

A comment on the lead

The first paragraph contains a factual incorrect sentence: "Amphetamine refers to equal parts of the enantiomers, i.e., 50% levoamphetamine and 50% dextroamphetamine." This is not correct. Amphetamine is a general term that can refer to either enantiomer, the racemate, or any mixture of the enantiomers. For example David Nutt's article (Heal et al 2013) contains the sentence "As a molecule with a single chiral centre, amphetamine exists in two optically active forms, i.e. the dextro- (or d-) and levo- (or l-) isomers or enantiomers." Aa77zz (talk) 11:40, 15 December 2013 (UTC)[reply]

  • In the strictest sense, amphetamine refers to the racemate,[1] [2] and in the loosest sense, it collectively refers (as "amphetamines") to every compound in the amphetamine class (e.g., a collective property reference like "amphetamine abuse"). Unfortunately, a lot of literature loosely uses this terminology in spite of it being an abuse of language (and the linguistic equivalent as well). Examples include ICD-10 and the Cochrane review - PMID 19160215 (hosted in the link below) - in the amphetamine psychosis article and the abstract of PMID 19042205, which is a paper on meth). For the sake of clarity, I used the FDA's terminology,[2] (page 11) which makes the distinction between amphetamine and dextroamphetamine. They implicitly refer to amphetamine as the racemate and refer to the pure forms and combinations of levoamphetamine and dextroamphetamine as "amphetamines" throughout their medication guides and Rx info sheets. Even though I personally think of amphetamine as any mixture of the enantiomers, due to the lack of uniform definition and the ambiguous (ab)use of terminology in medical literature, I thought it best to use similar precision to that in the FDA's publications. I should probably disambiguate the term more than the contents of note 3 though, so I'll work on it and then update this and ping you when I'm finished. Seppi333 (Insert 2¢) 19:20, 15 December 2013 (UTC)[reply]
    • Edit/Add: Almost forgot to mention this: the IUPAC name for amphetamine, (RS)-1-phenylpropan-2-amine, is racemic as well. Seppi333 (Insert 2¢) 19:23, 15 December 2013 (UTC)[reply]
      • Aa77zz, I tweaked the statement and added 2 chem refs. Let me know whether or not that suffices when you get a chance. Seppi333 (Insert 2¢) 05:16, 16 December 2013 (UTC)[reply]
        • @Aa77zz: I'm assuming you've been busy irl, but I'd really appreciate your feedback when you get a chance. Regards, Seppi333 (Insert 2¢) 16:23, 29 December 2013 (UTC)[reply]
  • Seppi333's itemized response (finished with these edits):
    • Moved the citations from each paragraph into a new note group at the end of the paragraphs. I wanted to retain the citations.
    • Fixed - I cut the less interesting/useful wikilinks
    • Removed quotes to non-WP:PAYWALLED (free) sources. The remaining sources aren't free, e.g. sources 12 & 13, so I left the quote since the average reader has no way to access these.
    • Deleted as many references as possible throughout the page. The remainder with 3+ literally need that many to maintain text-source integrity for WP:V.
    • Edited - Per Hamiltonstone's suggestion, I grouped a subset and cut relatively insignificant side effects - it's now a list with 12 items. For the drug list, I cut that in half - the list includes only Rx'd drugs now (9 drugs).
    • The stronger ref, titled "Westfall",can be found here. Edited: I decided to humor you and added a sentence about the difference in pharmacodynamics. I don't find the difference that interesting, since it just arises from variability in agonist potency at TAAR1.
    • Fixed - I removed this note.
Seppi333 (Insert 2¢) 19:13, 7 December 2013 (UTC)[reply]
Updated progress at 06:49, 9 December 2013 (UTC) - Seppi333 (Insert 2¢)

References

  1. ^ "Amphetamine (CAS entry)". NIH. NIH MESH. Retrieved 15 December 2013. Annotation: a specific chem: do not confuse with AMPHETAMINES; d-amphetamine = DEXTROAMPHETAMINE; N-methylamphetamine = METHAMPHETAMINE
  2. ^ a b "Adderall XR Prescribing Information" (PDF). United States Food and Drug Administration. June 2013. p. 11. Retrieved 7 October 2013.

Comments from Hamiltonstone[edit]

This looks like an excellent, if rather technical, article. Couple of things.

  • The article needs to begin by saying what Amph is. I'm not suggesting moving the whole pharmacology section to the top. But we need a first section, even if it is one para, that tells us what the substance/s is/are, and why they have that name.
    • Edited: When you get a chance, read the first paragraph of the lead and let me know if that addresses your concern. I made a few changes to the lead that should help clarify things.
      • Well, I wasn't actually looking for an edit in the lead. It is the body text of the article. The lead is supposed to summarise the article text, but at the moment the article text itself does not begin by telling us what an amphetamine is. I have noticed that other drug articles likewise begin with "use" sections. This looks to me to be a departure from what I thought WP's standard style was for articles about "stuff", that begin by defining what the "stuff" is and/or how the "stuff" got its name. See for example first sentence of Iridium or DNA, first section of Jaguar or Enzyme, or (somewhat differently), the opening of Nicotinamide adenine dinucleotide. I admit, though, that i expected to find a sentence about this in the MOS, and didn't, so maybe the MOS has changed or I am making stuff up...hamiltonstone (talk) 12:42, 11 December 2013 (UTC)[reply]
  • On the long lists, I agree with Aa77zz. They should be culled to include either the most significant or relevant items or, if that is not possible to determine, then a random sample. There is no point saying "including" and then actually including that many things.
    • I went through and deleted the drugs that aren't in current clinical use for the 2nd list; there's now 9 (were 17) in this list. For side effects, I cut it down to 2 lists, with the longer one containing 12 items. Should I make that shorter? :-) Seppi333 (Insert 2¢) 05:35, 9 December 2013 (UTC)[reply]
      • That looks better, maybe leave it there for now and see if anyone else has a view. Certainly, using a criteria such as 'current clinical use' to trim the list was exactly the sort of prioritisation I had in mind. hamiltonstone (talk) 12:42, 11 December 2013 (UTC)[reply]
  • I'd like to see what other editors have to say about the most technical parts of this article. I would question whether the Pharmacodynamics section is intelligible to anyone other than someone with relevant tertiary education in the area, and I would encourage simplification, as well as explanation in plainer English of what some of the points say and mean. But I know others have expressed a different view when I have discussed this kind of issue on other articles.

Looks extremely well researched and generally written with great precision. hamiltonstone (talk) 04:15, 9 December 2013 (UTC)[reply]

Thanks :-) It took a while to write. Seppi333 (Insert 2¢) 07:03, 9 December 2013 (UTC)[reply]
  • Under "uses", third para, second sentence, begins "He emphasized..." but i can't see who "he" was? hamiltonstone (talk) 12:43, 19 January 2014 (UTC)[reply]
  • In the section on "uses" we have this: "The current models on the etiology of ADHD involve impaired dopamine neurotransmission in the mesocortical and mesolimbic pathways and norepinephrine neurotransmission in the prefrontal cortex and locus coeruleus." First of all, I'm not entirely sure that the etiology of ADHD should be in the "uses" section of this article. But assuming it should, can we not favour a text that is a little less medically precise, and a little more readable by someone who is not already a student of medicine or pharmacology? What is "norepinephrine neurotransmission"? There isn't even a wikilink, but if there was, I'm not sure it would help a reader, given that this single sentence contains ten specialised medical or pharmacological terms. Why not rewrite it as something like "It is currently believed that ADHD is caused by problems with the operation of some of the brain's neurotransmitters, particularly the two chemicals dopamine and norepinephrine."?
    • Good point - I replaced it with a slightly modified version of your text and appended the technical description to it in a note. Changes Seppi333 (Insert 2¢) 16:56, 19 January 2014 (UTC)[reply]
  • The rest of "uses", "contraindications", "side effects" and "overdose" is pretty good. In overdose, though, we need a plain English alternative to "dopaminergic neurotoxicity". I had to guess that it means that it kills those neurons that are dopamine receptors, but I'm not sure, and the wikilink didn't help me solve that problem.
  • I had to take a pass on the pharmacology section. It needs more qualified reviewers than me who might understand it. Except to say that it needs a copyedit at one point to avoid the clumsy conjunction "...specific. Specifically,..."
  • I'm not happy with how "physical and chemical properties" starts. But I can't quite work out what the problems are. It begins "Amphetamine is a chiral compound and homologue of phenethylamine". Is it a compound in the singular? The lead says that is is an equal mix of two enantiomers. Are two enantiomers only one compound? I thought they would be two. Then "Physically, at room temperature, the free base of amphetamine is..." We have not been told what a "free base" is, and the term isn't linked anywhere. And specifying it this way implies that amphetimine presumably has different qualities to the free base of amphetamine, but these aren't described. Then we have "The racemic mixture can be divided into its optical isomers: levoamphetamine and dextroamphetamine". I don't think just linking "racemic" is sufficient. The sentence also reads like something from an old fashioned text book. Why are they "optical" isomers? And I didn't think they were isomers of the racemic mixture, as the sentence structure suggests - they are isomers of each other - sorry, that is cumbersome, but I can't say they are isomers of amphetimine, because the lead tells me that amphetamine is actually a name for a mixture of these two isomers. Also, why does not this first para tell us the chemical formula of amphetamine? Perhaps the section should begin along these lines: "Amphetamine is a mixture of the two chiral isomers levoamphetamine and dextroamphetamine, with the chemical formula ABC. It is a homologue (has a similar structure to) phenethylamine [insert fact about phenethylamine so we know why we care that it is a homologue of this thing]. Physically, at room temperature, amphetamine [ie. remove "free base of" unless you can explain to the reader the difference between the substance and the free base of the substance] is a mobile, colorless, and volatile liquid with a characteristically strong amine odor, and acrid, burning taste." hamiltonstone (talk) 13:29, 19 January 2014 (UTC)[reply]
    • The chemistry sections (basically everything in physical and chemical properties) are the only part of this article that I don't know inside and out, since I don't have much background knowledge in that area. Nonetheless, just based upon what I've read in the sources (responding to your questions in order, by group):
      • The amphetamine compound (by definition of that term) refers to the chemicals with the formula C9H13N and the trivial name "amphetamine", i.e., it refers to the free bases of dextroamphetamine and levoamphetamine. Those two have the same structure - they're just flipped. In comparison, the "term" "amphetamine" (see 3rd row) is typically a reference to a specific chemical - the free base of racemic amphetamine (this is stated in the lead citation that I hid in the source).
      • The free base and salts have the same pharmacological properties, but different chemical/physical properties (e.g., melting/boiling point, smell, etc). Since the free base of amphetamine is an unstable liquid, almost all licit and illicit amphetamine is produced as a salt (Benzedrine contained the free base though).
      • I made these changes in an attempt to address these issues, though it probably needs further revision - let me know what you think. Seppi333 (Insert 2¢) 16:56, 19 January 2014 (UTC)[reply]
        • In attempt to remove potential confusion concerning the sentence "Amphetamine is a chiral compound and homologue of phenethylamine" as well as to address the other comments above concerning this paragraph, I have made these edits. Please advise if there are any remaining concerns. Boghog (talk) 19:30, 19 January 2014 (UTC)[reply]
  • Thanks Seppi and Boghog, that's looking better. My note to delegates: I'm not buying in as a support or oppose, because I'm not sure what the view / standard is about an acceptable level of technicality in a WP article, which is a query for me on the Pharmacology section. I trust delegates, who see a wide range of articles, will be able to form the most intelligent view on that. In other respects I found the latest version relatively accessible, well-written and referenced.hamiltonstone (talk) 09:55, 20 January 2014 (UTC)[reply]

Comments from Anypodetos[edit]

Really great work, Seppi, thanks!

  • Do we need the notes? There's a Synonyms field in the drugbox (BTW, C9H13N is neither a synonym nor an alternative spelling), enantiomers and Mosher's acid are wikilinked for further information. I do see the point in the enantiomers note, but the chemical name of Mosher's isn't important in this article IMO.
    • Anypodetos, I appreciate the feedback. In any event, I removed the C9H13N term and the note next to Mosher's acid chloride. I made a note next to the first term in part because it was done by my GA reviewer in Psilocybin (FA) and because the drugbox extends halfway into the uses section in chrome on my laptop. It looks fine on my phone though. Seppi333 (Insert 2¢)
  • The ref from Molecular Neuropharmacology, ch. 13, contains a rather long quote. This seems to border on a copyvio. In general, do we need the quotes in the references? That's pretty unusual.
    • I cut that quote down and cut out 2 other quotes entirely, since they weren't really necessary or citing contentious content. I'm open to cutting the remaining quotes if their use seems to be an issue though. Seppi333 (Insert 2¢)
  • Abbreviations/tooltips: Should the number of {{abbr}} templates be reduced? Some paragraphs contain several tooltips of the same abbreviation, and the dotted lines cause some distraction from the text.
    • I cut out repeated abbr templates in all but 2 paragraphs and the pharmacodynamics diagram caption, since that's the densest technical part of the article. I can cut the remainder out if you think they're more distracting than helpful though - I don't have a preference on keeping or removing them. Seppi333 (Insert 2¢)
  • See WP:PHARMMOS#Sections (or WP:MOSMED#Drugs, medications and devices) for recommended section structure and naming.

--ἀνυπόδητος (talk) 19:42, 16 December 2013 (UTC)[reply]

  • I deviated from MEDMOS & PHARMMOS's layout slightly for a few reasons. (This is a comparison to MEDMOS, since MEDMOS and PHARMMOS actually differ slightly - e.g., contraindications and the section order :P)
  • I renamed Mechanism of action to "Pharmacodynamics" because the content included in pharmacodynamics is more general than mechanism of action (e.g., it wouldn't include the parts on SLC22A3, SLC22A5, CYP2A6, (the prior 3 are irrelevant to mechanism of action) and possibly CART as well, since its significance isn't completely understood yet.
  • I added a "Pharmacology" section and grouped the relevant headings under it so that the TOC limit would apply to the neurotransmitter headings (dopamine, serotonin, norepi, etc). The TOC sort of blows up without it and pharmacodynamics is already pretty long, so I figured it needed the subsections.
  • I renamed "Adverse effects" to "Side effects" because it includes both positive and negative things, as opposed to just undesirable effects.
  • I lumped "Dependence, addiction and withdrawal" together and put it in the OD section because those issues appear to occur together for the drug, but only occur at recreational doses (i.e., overdose) (all based upon the Cochrane review and FDA Rx info sheets).
  • Lastly, I removed interactions from the side effects section because, to me, it doesn't seem like a logical sub-category.
Also, while unrelated, I fixed the MOS:BOLD problem in {{more information}} for anyone else who uses it. Seppi333 (Insert 2¢) 22:06, 16 December 2013 (UTC)[reply]
Thanks for your answers! I see you put a lot of thought into this article :-) Maybe I'll remove some more redundant tooltips if you don't mind (only if there are several identical ones within a few lines), but I have no strong feelings about this issue either. I hope I'll have time to read the article thoroughly come weekend. Cheers, ἀνυπόδητος (talk) 20:35, 17 December 2013 (UTC)[reply]
Sure thing. Also, thanks for fixing those minor issues yesterday! Seppi333 (Insert 2¢) 21:00, 17 December 2013 (UTC)[reply]
Continued...
  • Contraindications
    • Several instances of "should" – see WP:NOTHOWTO. In Contraindications sections, I usually try either to say what dangerous things can happen if you take a drug under certain circumstances, or else write something on the lines of "the product information / manufacturer(s) advise against XY because studies are lacking / something bad could happen based on theoretical reasoning / etc." to avoid the impression that WP is advising readers not to take the drug.
    • "may still be prescribed to pregnant women in some circumstances[vague]" – do the sources say anything about which circumstances these are?
      • For the first issue, I rewrote the sentences to state that the USFDA was advising this. For the second issue, there wasn't anything concrete in the refs, so I used their wording to state in a nutshell that "it may be prescribed in cases where the potential benefits outweigh the risks." Let me know what you think of the current section - I more or less rewrote the paragraph. Seppi333 (Insert 2¢)
  • Physical side effects, 1st paragraph – see WP:LINKSTYLE, last bullet ("Do not unnecessarily make a reader chase links"); however, I'm not sure whether "... arrhythmias (irregular heartbeat, usually as tachycardia or fast heartbeat), hypertension (high blood pressure) or hypotension (low blood pressure) etc..." would make the paragraph better or worse.
  • Overdose, 1st paragraph – same as with side effects.
  • Interactions, 1st sentence – seems to have a grammatical error. Maybe there's just an "its" too much, but I'd rather leave it to you so I don't change the meaning.
    • Good catch - "and its the" was a bad typo IMO. I rewrote the sentence. Seppi333 (Insert 2¢)
      • Still not sure how understandable this sentence is, although I get it is talking about pharmacokinetic and pharmacodynamic interactions. If I can think of a better wording, I'll suggest it. --ἀνυπόδητος (talk) 09:54, 30 December 2013 (UTC)[reply]
        • Yeah... I struggled writing the revision, which IMO (ignoring the typo) is only a minor improvement. I don't think I worded it that well either. Seppi333 (Insert 2¢)
  • History, society, and culture, 3rd sentence – I assume "amphetamines" means "enantionpure and/or racemic amphetamine" here per the article convention, as opposed to "substituted amphetamines"? Just checking.
  • Chemical properties – does this really belong in the Pharmacology section? I was looking for a Synthesis section and unexpectedly found it here.
    • I decided on the sections to add to it using a statement in the lead of pharmacology (specifically, "the field encompasses drug composition and properties, synthesis and drug design, molecular and cellular mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, interactions, toxicology, chemical biology, therapy, and medical applications and antipathogenic capabilities."). That said, it's broad enough that I could've added basically every level 2 heading/section except "History, society, and culture" to it, so my choice was somewhat arbitrary. I really don't have a preference on section heading placement, so I wouldn't mind moving chemical properties and synthesis out of pharmacology if you think it seems a bit odd to have them there. Seppi333 (Insert 2¢)
      • I think it's somewhat odd that the Pharmacology article mentions synthesis. While WP:MOSMED doesn't mention a Pharmacology section (maybe just because is would encompass practically everything), it's pretty common to have such a section with the subsections Pharmacodynamics and Pharmacokinetics. I've moved the Chemistry section out of and below Pharmacology. --ἀνυπόδητος (talk) 09:54, 30 December 2013 (UTC)[reply]
        • Looks good! I think your arrangement of heading and subheadings is a more intuitive/logical categorization than what it was before. Seppi333 (Insert 2¢)

Note to self: Pharmacology section not reviewed yet.

Sorry for the delay! --ἀνυπόδητος (talk) 18:24, 29 December 2013 (UTC)[reply]

No worries - it's understandable since it's the holidays. Also, for convenience, these are all the changes I made for this round of edits.Seppi333 (Insert 2¢) 19:45, 29 December 2013 (UTC)[reply]
Next bit...
  • Pharmacokinetics
    • A short paragraph on bioavailability, first pass effect (if there is one), and protein binding would be nice. Could do that myself, but not today
      • Amphetamine has very weird pharmacokinetics (IMO) - basically everything is pH dependent. I've looked a few times for a mention of first pass effects, but haven't found anything specifically on amphetamine in MEDRS refs (including HSDB/toxnet and pubchem). I didn't mention (oral) bioavailability in the article it's far too dependent on pH to give a meaningful figure; I've found very few mentions of the bioavailability of any amphetamine salts or the free base via different routes.
The only ref I've found for oral was a range on oral D-amph bioavailability (pubchem page) that I don't think is correct at acidic pH. Besides the acid/alkaline interactions in the prescribing info for adderall, I've read a few primary sources that indicate the use of high-dose acidic compounds (e.g., vitamin C) immediately following an amphetamine overdose results in markedly reduced absorption from the upper GI tract. In contrast, alkaline solutions, especially oral laxative antacids that don't absorb well throughout the GI tract (magnesium hydroxide), can greatly increase oral bioavailability. I'm not sure whether it's better to expand upon the vague bioavailability statements in the FDA interactions with this or only state the interactions information out of concern for what some readers might do with that information. Seppi333 (Insert 2¢)
  • Could you review my addition? Paragraphs 1 and 2 of Amphetamine#Pharmacokinetics. I didn't mention any reasons for high or low GI pH to address your concerns about readers, and also because it's already in the interactions section. Thanks --ἀνυπόδητος (talk) 17:11, 5 January 2014 (UTC)[reply]
    • Looked good. Made 2 minor text edits and distributed the associated refs. Seppi333 (Insert 2¢) 00:13, 6 January 2014 (UTC)[reply]
    • Almost forgot to add: In the event you noticed this (it looked pretty stupid IMO), I fixed the whitespace after the section - it was coming from the transclusion template. Seppi333 (Insert 2¢) 00:22, 6 January 2014 (UTC)[reply]
    • I doubt very much whether the half-lives given in the prescribing info for different age groups are statistically significantly different. I'd say dex-amph has a half-life of 9 to 11 hrs, and levo-amph has 11 to 14 hours. Anything more precise probably can't be measured anyway.
  • Detection in body fluids: This section seems a bit unclear about some points.
    • Are the "chiral-separation techniques" from paragraph 1 the same as Mosher's acid chloride from para 3?
      • It's used as the separating agent in one of the techniques - I wrote in a note that Aa77zz wanted me to delete that Mosher's acid chloride is (S)-(+)-α-methoxy-α-(trifluoromethyl)phenylacetyl chloride; I used the Mosher's acid wikilink because that chemical name is hideous and long. This is one of the two sections (other being synthesis) that I'm actually completely unfamiliar with the science behind. Granted, I understand this section a little better than I do synthesis - Boghog wrote that section.Seppi333 (Insert 2¢) 00:13, 6 January 2014 (UTC)[reply]
    • Not sure how the (two-way) distinction of racemate vs. dextro facilitated by the chiral-separation techniques can distinguish between all those sources mentioned in para 1. Are all the legal sources enantiopure and all illegal ones racemic? Or what?
      • Based upon what I gathered from reading the abstracts and parts of the papers I could understand a month ago, the enantiomers in amphetamine pharmaceuticals have a predictable ratio with which they break down. Since street substituted amphetamines (usually mostly dextromethamphetamine) usually have a different ratio than amphetamine pharmaceuticals or Vicks Vapoinhaler, the enantiomeric ratio in urine can be compared to that. AFAIK, Benzedrine isn't sold in the US anymore, and since the only product with levoamph is Adderall (25% levoamph 75% dextroamph [or as the FDA puts it: 50% amph 50% D-amph]), the presence of the racemate's urinary enantiomeric ratio without levomethamphetamine would indicate consumption of illicit racemic amphetamine. Again though, I don't know this field/topic particularly well.Seppi333 (Insert 2¢) 00:13, 6 January 2014 (UTC) Added: I have no clue how they account for the potential presence of legal Desoxyn use. Add again: my best guess as to how this works is they use a panel of drug derivatizing methods to determine enantiomeric ratios and then determine if the ratio of methamphetamine and amphetamine enantiomers (and those of prodrugs any potential prodrugs) falls within the possible range of ratio values that could conceivably come from taking a combination of legal substituted amphetamines. The presence of D-methamphetamine in the absence of a prodrug would probably raise a red flag, because Desoxyn is so rarely prescribed (it's a neurotoxin, after all). Seppi333 (Insert 2¢)[reply]
    • "GC–MS of amphetamine and methamphetamine ... allows for the detection of methamphetamine in urine." Um, doesn't it allow for the detection of amphetamine as well? "... allows for the detection of both substances, but does not distinguish enantiomers"?
      • From what I gather, the results of GC-MS depend on the derivatizing agent used. The first is a non-chiral agent, so it detects the presence of either enantiomer. With Mosher's acid chloride, it's possible to detect D-meth (something like 10% breaks down into D-Amph, so D-meth implies the presence of D-amph.), which is by far the most common street substituted amphetamine. I wrote that paragraph mostly from the abstract, and partly the body, of this paper.[1] Again, I'm not entirely familiar with this field though. Seppi333 (Insert 2¢) 00:13, 6 January 2014 (UTC)[reply]
    • Maybe this subsection would fit better in the chemistry section. I'll leave that decision to you.
  • Transclusion: Not sure, but I think you should move User:Seppi333/AnnotatedImage to Template namespace. Transcluding from User to Article space shouldn't be done AFAIK.

--ἀνυπόδητος (talk) 21:55, 4 January 2014 (UTC)[reply]

References

  1. ^ Paul, BD (2004 Sep). "Enantiomeric separation and quantitation of (+/-)-amphetamine, (+/-)-methamphetamine, (+/-)-MDA, (+/-)-MDMA, and (+/-)-MDEA in urine specimens by GC-EI-MS after derivatization with (R)-(-)- or (S)-(+)-alpha-methoxy-alpha-(trifluoromethy)phenylacetyl chloride (MTPA)". Journal of analytical toxicology. 28 (6): 449–55. PMID 15516295. {{cite journal}}: |access-date= requires |url= (help); Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)

Comments from The Sceptical Chymist[edit]

  • Support with some reservations. A formidable undertaking, generally well-written and sourced. Some places in the article are vague or tangential, they can be shortened. Things to improve:
  • Remove less important info from the lead: Amphetamine is the parent compound of its own structural class...
  • I'm not sure how I could reword this without cutting out the whole sentence and note 3 (which is more important than it might seem on the face of it - see #abuse of language) Seppi333 (Insert 2¢)
  • Not needed: The exact etiologies of ADHD are not completely understood...
  • In the medical uses, some citations are about use in adult ADHD, some in children. This has to be noted
  • I can only find 1 where I forgot to mention this - the Millichap text - did you notice any others? In any event, I added the text for that ref. Seppi333 (Insert 2¢)
  • bupropion, .. increases stamina and endurance... Not sure
  • It's what the ref says - the review cited 1 or 2 (i forget which) papers where it improved performance wrt controls but the mechanism is dopamine reuptake inhibition, so it's entirely within the realm of that drug's pharmacodynamics. Seppi333 (Insert 2¢)
  • USFDA? - FDA is a customary abbreviation
  • I appended the US term simply because there's currently more than 1 FDA on the page (Thailand Food and Drug Administration). Seemed necessary to disambiguate. Seppi333 (Insert 2¢)
  • At normal therapeutic doses, the physical side effects of amphetamine vary widely by age and among individuals. - vague. How is it varied by age
  • The Rx info didn't really go too much into it, but there seemed to be an upward trend in gastrointestinal symptoms between children, adolescent, and adults. The most obvious difference by age was the children and adolescents are susceptible to temporary effects on their growth (height/weight), whereas this is irrelevant to adults. Seppi333 (Insert 2¢)
  • Side effects, in general. Frequent side effects and rare but severe side effects have to be highlighted. Skip (rare AND insignificant) side effects.
  • The Adderall XR Rx info noted that, due to the heterogeneity in clinical studies, the side effects they listed can't be generalized beyond the sub-populations noted in the side effects tables. The only mention of the word rare in the Rx info pertain to rare complications of possible side effects (independent of amphetamine, like ulceration in Raynaud's, which is a rare complication of Raynaud's) The Westfall ref also noted tolerance to some effects over time, so common vs rare effects aren't time invariant. I wish there was something more useful I could add in comment on this, but beyond acute toxic reactions, there don't seem to be any real rare side effects - they're just inevitable at sufficiently high doses. Seppi333 (Insert 2¢)
  • Dangerous physical side effects are quite rare in typical pharmaceutical doses. - Specify which and how rare
  • The acute toxic reactions mentioned above (occurring at idiosyncratically low doses)- a frequency wasn't provided in any ref, the ones that mentioned this just said it was rare. Seppi333 (Insert 2¢)
  • erectile dysfunction, frequent erections, - which are more frequent
  • This might sound odd, but both may occur to the same person in the same day. In any event, the refs didn't specify a frequency, this was added with the recent December 2013 labeling revision to all amphetamine pharmaceuticals - see this diff's comment Seppi333 (Insert 2¢)
  • Amphetamine may reduce gastrointestinal motility if intestinal activity is high, or increase motility if the smooth muscle of the tract are relaxed - vague. explain conditions more specifically. what happens more often
  • The former means it takes longer for contents to move through the intestine - the latter, the opposite. The ref (quote included) [1] doesn't elaborate. Seppi333 (Insert 2¢)
  • when respiration is already compromised, it may stimulate respiration. - vague
  • alertness, concentration, decreased sense of fatigue, self-confidence, and sociability - are not adverse effects
  • I agree - that's primary why I named the top-level section "effects" instead of "side effects" or (I think JMH649 edited this to "side effects" during one of my feedback requests from him - still, his term for the section also encompasses beneficial effects) "adverse effects" Seppi333 (Insert 2¢)
  • hypotension (low blood pressure) from a vasovagal response - awkward, use Vasovagal syncope
  • Eh, it doesn't necessarily require passing out for the effect to present itself. I can use a different synonym like vasovagal reaction or vasovagal episode if you'd prefer. I just used vasovagal response because that's the article title. Seppi333 (Insert 2¢)
  • Overdose: highlight most frequent and dangerous effects and symptoms.
  • They're already grouped by danger/severity, although it's indicated as level of OD; everything in the last OD sentence is a medical emergency. Frequency is unknown, like all other case of this =/ Seppi333 (Insert 2¢)
  • An amphetamine overdose is rarely fatal with appropriate care - what is the care? what about strokes?
  • Cerebral hemorrhage (the most dangerous side effect by far) seems to be mentioned more than stroke in newer toxicity literature I've seen. I'll look into some toxicology texts and flesh out an OD paragraph on treatment in the coming week - need to find a good text for this. Seppi333 (Insert 2¢)
  • high or low blood pressure - confusing, specify when each of them happens. E.g. low blood pressure when in coma
  • It's not listed, but I imagine it's the same mechanisms as at normal doses (the opposing effects of various NE/DA receptors in the blood vessels on venous dilation) Seppi333 (Insert 2¢)
  • While addiction is a serious risk with heavy recreational amphetamine use, it is unlikely to arise from typical medical use - how unlikely, what is the number?
  • in treating abuse and addiction - abuse and addiction are two different things. more details needed
  • about 5–15% of users fail to recover completely - give time frame, within what period they fail to recover - 1 week? 1 year?
  • I think it meant there were permanent residuals effects. That's all the ref said on that. It's titled "Cochrane" in the above link. Seppi333 (Insert 2¢)
  • dopaminergic neurotoxicity with sufficiently high doses of amphetamine - if in the article, provide estimate of how high compare to therapeutic dose
  • Not in it, though I imagine around or above the level to induce toxic symptoms, since there's no papers I've seen of amphetamine addicts with terminal degradation Seppi333 (Insert 2¢)
  • The primary proposed mechanism... - Delete. No need to explain the effect that is not observed in humans. No need for in vitro data
  • Removing this might really piss off another editor (Exercisephys) so I need his input before making any changes to this section (it's been a point of contention) Seppi333 (Insert 2¢)
  • Thanks for the heads-up, {Seppi333. I'm fine with the last sentence being removed as its claim is a lot less established than the previous few. However, Seppi333 likely wants it around to maintain the neutrality. As far as the primary proposed mechanism goes, that's very well-established and widely accepted. The primary reason it hasn't been explored in humans is just medical ethics. This was once mentioned in that section but has since been removed. We could restore it if you want. I definitely think that statement should stay, though, as it's a pretty universally accepted and central theory. Exercisephys (talk) 21:08, 12 January 2014 (UTC)[reply]
  • CYP2D6 inhibitors, such as selective serotonin reuptake inhibitors (SSRIs) - not all of ssri's, delete that part.
  • Deleted/replaced with "such as fluoxetine (an SSRI)" since fluoxetine was mentioned as 1 of 2 treatments for abuse/addiction further down the page Seppi333 (Insert 2¢)
  • will prolong the elimination half-life of amphetamine - By how much? What is the clinical significance? With what specific drugs was observed in clinic?
  • From my understanding, complete inhibition will halt the metabolism along the para-hydroxylation pathways, so it will increase the amount of amphetamine to excrete that would have been lost through that route, which isn't a trivial proportion for people who aren't weak metabolizers on CYP2D6. The effect size depends on metabolic activity on that enzyme between people (strong metabolizers/weak metabolizers will see different results). Seppi333 (Insert 2¢)
  • amphetamine also interacts with monoamine oxidase inhibitors (MAOIs) - MAO-A or MAO-B or both? Are there examples of cases from literature?
  • Moreso MAO-B than MAO-A since: amphetamine is a weak-moderate MAO-B inhibitor and most catecholamines and notable/relevant trace aminergic phenethylamines are either preferential or fully selective substrates of MAO-B. Ya, it's pretty dangerous to combine them, though the explanation as to why will require a paragraph (related to phenethylamine).Seppi333 (Insert 2¢)
  • While there is no significant effect on consuming amphetamine with food in general, the pH of gastrointestinal content and urine affects the absorption and excretion of amphetamine, respectively.[73] Specifically, acidic substances will reduce the absorption of amphetamine and increase urinary excretion, while alkaline substances do the opposite.[73] Due to the effect pH has on absorption, amphetamine also interacts with gastric acid reducers such as proton pump inhibitors and H2 antihistamines, which decrease gastrointestinal pH. - vague. with what acidic substances? clinical significance and literature on interaction with antacids (my guess it is low)
  • There's a very significant pH effects on both absorption and excretion w.r.t. alkaliniy/acidity. If the diet is very acidic, neutralization of pH in the upper GI will have a very large effect on absorption there. Excretion is mentioned in pharmacokinetics (doubles to triples elimination half-life for alkaline). Absorption I didn't mention for concerns about information use (mentioned in Anypodetos' section above) Seppi333 (Insert 2¢)
  • Section on pharmacodynamics contains a lot of general tangential information. Example: "The most widely studied neurotransmitter with regard to amphetamine action in the central nervous system is dopamine".
  • At high doses, amphetamine inhibits monoamine oxidase - which? are these doses clinically relevant?
  • This likely contributes to the nootropic effects of amphetamine - nootropic effects are speculative
  • I wasn't the author of the piece of text, but I decided to keep it simply because I had addressed improvements in working memory (as a result of improved cortical network efficiency - reference) on individuals from the general population in the first paragraph of the amphetamine#performance-enhancing section. Seppi333 (Insert 2¢)
  • consequently, when the pH is basic, more of the drug is in its lipid soluble free base form, and more is absorbed through the lipid-rich cell membranes of the gut epithelium.[3][73] Conversely, an acidic pH means the drug is predominantly in its water soluble cationic form, and less is absorbed.[3][73] - what is the clinical significance? what are examples of acidic and alkaline diet? what are overall effects of acidic/alkaline diet from the point of overall action of amphetamine
  • More Alkaline= higher bioavailability (I don't want to explicitly state this) and markedly lower excretion. More acidic= the opposite. Food examples is waaaaay too general/broad for inclusion IMO. Edit: In a nutshell, this means it's a higher/lower effective dose at all ranges of time values for alkaline/acid respectively, but I don't want to state that for the same reason as bioavailability. Seppi333 (Insert 2¢)
  • Apparent half-life and duration of effect increase with repeated use and accumulation of the drug.[93] - when does it reach equilibrium?
  • No clue - haven't seen a ref assert that. I imagine there's some pretty weird dynamics with enzymatic metabolism as doses become really high. Seppi333 (Insert 2¢)
  • What are major metabolites (including inactive). Note on the scheme which is the main metabolic pathway
  • This probably varies between strong/weak metabolizers of CYP2D6/FMO, but in general it's the phenylacetone branch. I'll add this to the diagram when I have some time this week. I've added all this information to the caption, though not the material on the variability from strong/weak metabolizers differences (e.g., CYP2D6#Genetic basis of variability). Seppi333 (Insert 2¢)
  • Synthesis - which one is used in manufacture? Remove R-s in Knoevenagel scheme since they = H. In the second dcheme, the formula for hydroxylamine, should be NH2OH not NH3.
  • I'll need to have Boghog answer this, because I'm clueless when it comes to chem. Seppi333 (Insert 2¢) Edited: Actually, I don't think Boghog would know the legal method (I have no clue either) - this very like different between manufacturers and certainly between pharmaceutical type (e.g. pure dextro, adderall, vyvanse). The primary illicit method, the Leuckart method, is indicated for illicit amph. Seppi333 (Insert 2¢) 01:52, 11 January 2014 (UTC)[reply]
  • References 3, 10 and 19 are the same
  • Page numbers differ - they're short cites. I think there's between 5-10 cites to the Adderall XR info with different page numbers Seppi333 (Insert 2¢)
  • General note: prescribing information is the property of the manufacturer. FDA can only suggest corrections to it. A compromise version of prescribing information between FDA and the manufacturer is usually approved by FDA. Therefore you should not write " According to the United States Food and Drug Administration..." and then refer to the prescribing information. The best is to say according to the prescribing information or according to the manufacturer's label (you can add approved by FDA, if you wish).
  • I've attempted to address this with a revision to the first sentence and a note following the revised text in amphetamine#Contraindications. I couldn't think of a better way to state this since there's at least 5 different amphetamine pharmaceuticals I can think of at the moment available in the US, most of which have multiple generic manufacturers. Let me know if you think this could use further revision. Seppi333 (Insert 2¢) 01:47, 11 January 2014 (UTC)[reply]
Thanks for the feedback! I'll try to work through this list promptly. Seppi333 (Insert 2¢) 05:31, 9 January 2014 (UTC)[reply]

References

  1. ^ From Westfall: "The GI effects of amphetamine are unpredictable. If enteric activity is pronounced, amphetamine may cause relaxation and delay the movement of intestinal contents; if the gut already is relaxed, the opposite effect may occur."

Comments from Axl[edit]

  • From the lead section, last paragraph: "Amphetamine is the parent compound of its own structural class... which includes... methamphetamine. It is chemically related to methamphetamine." Isn't the second statement obvious from the first statement? Axl ¤ [Talk] 00:29, 12 January 2014 (UTC)[reply]
  • Yes, I think so. I only used it as a lead-in clause for the comparison that was made in that sentence. I wouldn't mind rewording it if you can think of a more fluid/less redundant way of expressing that (assuming I don't come up with something today). Seppi333 (Insert 2¢)
I have changed the text. Axl ¤ [Talk] 01:22, 16 January 2014 (UTC)[reply]
  • From "Uses", subsection "Medical", paragraph 2: "others noted reductions to dopamine-associated structures and metabolites." Perhaps mention the structures (substantia nigra? basal ganglia?). Axl ¤ [Talk] 03:28, 12 January 2014 (UTC)[reply]
  • Because these are animal studies, I didn't really want to expound on its adverse effects on non-human primate neuroplasticity since it's not relevant to humans - an opposite effect in humans is covered in the next sentence. Seppi333 (Insert 2¢)
Okay. Axl ¤ [Talk] 01:23, 16 January 2014 (UTC)[reply]
  • "Uses", subsection "Medical", paragraph 3 contains two quotes from Millichap. Is this really a controversial subject where a direct quote would be superior to paraphrasing? Axl ¤ [Talk] 10:49, 13 January 2014 (UTC)[reply]
Thank you. I'll trust your judgement that Millchap's opinion deserves a paragraph. Axl ¤ [Talk] 12:31, 16 January 2014 (UTC)[reply]
  • From "Uses", subsection "Medical", quote from the Cochrane Collaboration: "Amphetamines were associated with higher attrition due to adverse events." I presume that "attrition" in this context refers to discontinuation of treatment. Compared to which group is there higher attrition? (I presume that the other group is placebo, because that is usually what Cochrane looks for as the control.) The preceding statement is: "[Adderall] also increased retention in treatment." Does this mean that the attrition rate with Adderall is lower than the rate in the control group? Superficially, this seems to contradict the other statement. Or is there a higher attrition rate in the control group for reasons other than adverse events? Overall, this out-of-context quote is unhelpful. Axl ¤ [Talk] 12:35, 17 January 2014 (UTC)[reply]
Ah, other ADHD treatments, not placebo. Thanks. Axl ¤ [Talk] 13:43, 18 January 2014 (UTC)[reply]
  • From "Uses", subsection "Medical", last paragraph: "A Cochrane Collaboration review on the treatment of ADHD in children with comorbid tic disorders indicated that stimulants in general do not exacerbate tics, but high-dose dextroamphetamine use in such individuals should be avoided." This implies that high-dose dextroamphetamine in ADHD without tic disorders is acceptable. Is that correct? Axl ¤ [Talk] 12:41, 17 January 2014 (UTC)[reply]
Thanks. Axl ¤ [Talk] 13:54, 18 January 2014 (UTC)[reply]

Closing comment This candidate has been here a long time but there is no indication that a consensus for promotion will be achieved on this occasion and I will be archiving this in a few minutes. I urge the nominator to resolve remaining issues on the article's talk page and return this to FAC later. This can be done after two weeks from when the closing bot runs. Graham Colm (talk) 21:53, 21 January 2014 (UTC)[reply]

The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.
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