Selegiline in Narcolepsy

We examined the effect of the specific monoamine oxidase-B (MAO-B) inhibitor selegiline (deprenyl, Eldepryl), 20-30 mg p.o. daily, in 21 subjects with the narcoleptic syndrome for 4 weeks. Selegiline was compared to no treatment (7 subjects) or conventional central stimulant drugs, including dexamphetamine or mazindol (14 subjects). Severity and frequency of narcolepsy, accessory symptoms, and effects of selegiline on mood were measured. Selegiline, as well as causing MAO-B inhibition, is interconverted to amphetamine. Urinary amphetamine and methamphetamine excretion were determined in 18 subjects after 4 weeks on selegiline and the results were compared with amphetamine excretion in subjects on dexamphetamine. The effect of selegiline, 20-30 mg p.o., on alertness and mood was similar to that of dexamphetamine in the same dosage, with comparable sympathomimetic side effects. Selegiline, 20 mg p.o., caused a subjective increase in alertness for 4-8 h. Mean urinary amphetamine excretion on dexamphetamine, 15-70 mg daily (mean 29 mg) at pH 5.6-6.6, was 5,184 micrograms/24 h, and on selegiline, 20-30 mg daily (mean 22.5), was 4,127 micrograms/24 h. We conclude that selegiline, 20-30 mg daily, requires further evaluation in narcolepsy.