Safinamide

Safinamide (INN; brand name Xadago) is a drug used as an add-on treatment for Parkinson's disease during 'off' episodes; it has multiple modes of action, including the inhibition of monoamine oxidase B. Safinamide (INN; brand name Xadago) is a drug used as an add-on treatment for Parkinson's disease during 'off' episodes; it has multiple modes of action, including the inhibition of monoamine oxidase B. It was approved in Europe in February 2015, in the United States in March 2017, and in Canada in January 2019. Safinamide is used to treat idiopathic Parkinson’s disease as add-on for people taking a stable dose of levodopa (L-dopa) alone or in combination with other Parkinson drugs, to help with 'off' episodes when levodopa stops working. Safinamide is contraindicated in people with severe liver impairment, with albinism, retinitis pigmentosa, severe diabetic neuropathy, uveitis and other disorders of the retina. Combination with other monoamine oxidase (MAO) inhibitors and pethidine is also contraindicated. It is pregnancy category C in the US; it is not safe for women to take during pregnancy. It is excreted in breast milk and the effects on infants are unknown. Common adverse events in clinical trials (in more than 1% of people) included nausea, dizziness, tiredness, sleeplessness, orthostatic hypotension (low blood pressure), and headache. There was no significant difference in the occurrence of these effects between safinamide and placebo. In experiments with rats (but not in those with monkeys), retinopathies have been observed. Expected overdose effects are hypertension (high blood pressure), orthostatic hypotension, hallucinations, psychomotor agitation, nausea, vomiting, and dyskinesia. In studies, a single person was suspected to have overdosed for a month; symptoms were confusion, drowsiness and mydriasis (dilation of the pupils) and subsided completely after the drug was discontinued. No specific antidote is available. As a MAO inhibitor, safinamide can theoretically cause hypertensive crises, serotonin syndrome and other severe side effects when combined with other MAO inhibitors or with drugs that are known to interact with MAO inhibitors, such as pethidine, dextromethorphan, selective serotonin reuptake inhibitors (SSRIs), serotonin–noradrenaline reuptake inhibitors (SNRIs), tricyclic and tetracyclic antidepressants. An interaction with tyramine, a substance found in various foods, could be expected by the same reasoning but has been excluded in studies.