Evaluation of the Potential for Pharmacodynamic and Pharmacokinetic Drug Interactions Between Selegiline Transdermal System and Two Sympathomimetic Agents (Pseudoephedrine and Phenylpropanolamine) in Healthy Volunteers

Abstract

Selegiline transdermal system is a recently approved monoamine oxidase inhibitor antidepressant. Medications that inhibit monoamine oxidase type A can augment the pressor effects of sympathomimetic amines, increasing the potential for hypertensive crisis. This study examined the potential for drug-drug interactions during treatment with selegiline transdermal system and pseudoephedrine or phenylpropanolamine. Two studies were conducted with 25 healthy volunteers to assess changes in blood pressure and heart rate during administration of pseudoephedrine or phenylpropanolamine alone or together with selegiline transdermal system. No significant differences in mean maximum changes in vital signs occurred with pseudoephedrine. No significant differences were found in mean maximum changes in systolic heart rate with phenylpropanolamine; however, 4 of 12 subjects each experienced 1 isolated protocol-defined minimal pressor response without concurrent adverse effects (1 with phenylpropanolamine alone; 3 with phenylpropanolamine + selegiline transdermal system). Pharmacokinetic parameters obtained following selegiline transdermal system and pseudoephedrine or phenylpropanolamine were unremarkable. The results suggest that selegiline transdermal system 6 mg/24 h does not significantly alter the pharmacodynamics or pharmacokinetics of either pseudoephedrine or phenylpropanolamine when administered to healthy volunteers; however, it is prudent to avoid coadministration of selegiline transdermal system and sympathomimetics.

Pseudoephedrine—Benefits and Risks

“…Combination with caffeine present in many OTC medications, dietary supplements and energy drinks may cause hyperglycaemia and an increase in body temperature. Pseudoephedrine used concomitantly with the drugs listed in Table 3 may cause undesirable interactions, resulting in the weakening or potentiation of the drug effects [ 18 , 19 , 36 ].…”

Practical guide for prescribing MAOIs: debunking myths and removing barriers

“…34 Small, open-label studies have been conducted to investigate potential drug-drug interactions between transdermal selegiline and sympathomimetics. 37 Change in heart rate and blood pressure was evaluated in a sample of 25 healthy controls during administration of pseudoephedrine (or phenylpropanolamine) alone, transdermal selegiline alone, or the combination. No significant differences were found.…”