Selegiline: Price, Dosage & Where to Buy

Selegiline is a monoamine oxidase B inhibitor used as an additional treatment for Parkinson's disease when the response to levodopa/carbidopa has deteriorated. It helps support the effect of existing treatment rather than replacing it, and requires a prescription in the United Kingdom. The tablet label describes benefits including reduced periods when Parkinson's symptoms return between doses.

Selegiline inhibits monoamine oxidase B, an enzyme involved in breaking down dopamine in the brain. Dopamine is a chemical messenger that helps control movement. By slowing its breakdown, selegiline can support the effects of levodopa, which is converted into dopamine.

Its selectivity for this enzyme is not absolute and decreases at higher doses. Inhibition of other monoamine oxidase activity can affect the handling of other chemical messengers and substances in food, helping explain some of its important interactions.

Selegiline tablets are indicated for people with Parkinson's disease who are already receiving levodopa/carbidopa but whose response to that treatment has become less satisfactory. They are used as an additional treatment, rather than on their own. The label reports reduced 'off' time, meaning periods when the benefit of treatment wears off and symptoms return.

Benefits were also observed in tremor, excess saliva, speech, dressing ability and walking, as well as difficulty moving towards the end of a levodopa dose's effect. Controlled studies have not established a beneficial effect when selegiline is used without concurrent levodopa treatment.

The label lists oral capsules and tablets containing 5 mg, orally disintegrating tablets containing 1.25 mg, and transdermal patches delivering 6 mg/24 h, 9 mg/24 h or 12 mg/24 h. The label lists a recommended oral tablet regimen of 10 mg per day, divided into 5 mg at breakfast and 5 mg at lunch, for Parkinsonian patients already receiving levodopa/carbidopa. This regimen relates to the conventional oral tablets; it does not establish dosing schedules for the other formulations.

The label states that higher doses have no demonstrated additional benefit and increase the risk of side effects. During treatment, the prescriber may consider reducing levodopa/carbidopa as the response changes.

Such adjustments concern the accompanying Parkinson's treatment and require clinical supervision. The different formulations should not be assumed to share the tablet regimen.

The tablet label specifies storage at 20° to 25°C in a tight, light-resistant container with a child-resistant closure. Keep medicines out of the sight and reach of children, and follow the packaging instructions for the particular formulation.

A missed dose should not be made up by doubling a later dose. Follow the leaflet for the specific formulation, as tablets and patches have different schedules.

If the next scheduled dose is close, the missed dose is generally omitted. A pharmacist can clarify the appropriate approach if there is uncertainty.

There are no adequate, well-controlled studies of selegiline in pregnant women. Animal studies reported adverse effects on fetal growth and offspring survival, although no teratogenic effects were observed in the embryo-fetal studies described.

The label states that use during pregnancy should occur only if the potential benefit justifies the potential risk to the fetus. The label does not specify breastfeeding information; discuss pregnancy or breastfeeding with a doctor or pharmacist.