Drug interactions between Azilect and carbidopa/levodopa

MONITOR: Rasagiline may potentiate the dopaminergic side effects of levodopa and exacerbate preexisting dyskinesia. The mechanism is rasagiline inhibition of the breakdown of dopamine via monoamine oxidase. In clinical trials, treatment-emergent dyskinesia occurred in about 18% of patients treated with rasagiline 0.5 or 1 mg/day as adjunct to levodopa, compared to 10% of patients who received levodopa with placebo. Decreasing the dose of levodopa may ameliorate this effect. The incidence of postural hypotension and hallucinations was also increased with the combination. Postural hypotension was reported in approximately 6% and 9% of patients receiving levodopa in combination with rasagiline 0.5 and 1 mg/day, respectively, compared to 3% of patients receiving rasagiline 1 mg/day or levodopa alone. Similarly, hallucinations were reported in approximately 5% of patients receiving levodopa with rasagiline, compared to 3% of patients receiving levodopa alone and 1.3% of patients receiving rasagiline 1 mg/day alone.

MANAGEMENT: Patients receiving rasagiline as an adjunct to levodopa should be advised of the possibility of increased dyskinesia and postural hypotension. Patients should be cautioned to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Postural hypotension occurs most frequently in the first two months of rasagiline treatment and tends to decrease over time.