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Contraindications

Daytrana® is contraindicated in persons who suffer from anxiety, tension, agitation, glaucoma, or those who are sensitive to methylphenidate or any ingredient in the formulation . This medication is not to be used when currently use MAOIs or have used an MAOI within the past 2 weeks. If an individual has a history of drug dependence or alcoholism, prescribers should proceed with caution as “chronic abusive use can lead to marked tolerance and psychological dependence with varying degrees of abnormal behavior” .

Adverse Effects

Common adverse effects are skin irritation at application site, nausea, and dizziness. Other adverse effects include :

• Decreased appetite
• Insomnia
• Decreased weight
• Abdominal pain
• Headache
• Palpitations
• Anorexia
• Irritability
• Dyskinesia (tics)

According to the U.S. Food and Drug Administration, “blood pressure and heart rate increases have been observed in patients treated with the sympathomimetic methylphenidate” . Also, recent studies have shown that there is not a correlation between the use of methylphenidate and cardiovascular events . Due to the potential of these adverse effects, patients should be closely monitored for the potential appearance of these reactions. The patch should not be worn for longer than 9 hours, even if a new patch was placed due to the previous patch falling off.

Interactions

Caution should be taken when used with vasopressor agents (antihypotensive agents) as they could increase blood pressure and may decrease the effects of medications used to treat hypertension.

Methylphenidate also is reported to inhibit the metabolism of Coumadin (warfarin) and other related anticoagulants possibly through several P450 pathways, but specifically through CYP2C9 . Studies have shown that methylphenidate inhibits the metabolism of warfarin as well as other anticoagulants via several cytochrome P450 pathways . Thus, dose adjustments should be considered in a patient who is taking an anticoagulant while using this medication.

Blackbox Warning

Daytrana® has a U.S. Boxed Warning since there is a potential for dependency and therefore should not be discontinued suddenly in patients who have received the medication for a long period of time . Use caution in patients with history of ethanol or drug abuse.

Mechanism of Action

Methylphenidate is a CNS stimulant and Daytrana is the long acting transdermal patch formulation. Methylphenidate works in the CNS to selectively inhibit the presynaptic reuptake of dopamine and norepinephrine. It has been demonstrated to block dopamine transporter molecules and increase extracellular levels of dopamine in the striatum of healthy adults .

Pharmacokinetics

The peak concentration of methylphenidate in patients using Daytrana® is 39 nanograms/mL and the time it takes to reach this is between 7.5 to 10.5 hours . However the onset to peak effect is 2 hours and the clinical effects remain up to 2 hours after patch has been removed. The absorption of Daytrana® is increased when the transdermal patch is applied onto inflamed skin or skin that has been exposed to heat. The absorption is continuous for 9 hours after application (onto normal, unexposed to heat, and uninflammed skin). 90% of the medication is excreted in the urine as metabolites and unchanged drug .

In Pregnancy

The FDA has labeled Daytrana® as a Category C medication in pregnancy, and so it was found to have adverse effects in the fetus when studied in animals. However, there have not been enough studies performed in humans that show that the benefits of using Daytrana® are outweighed by potential adverse effects .