Eldepryl

Eldepryl contains selegiline, which selectively blocks monoamine oxidase type B, the enzyme that breaks down dopamine in the brain. Keeping more dopamine available helps with the slowness, stiffness and tremor of Parkinson's disease. According to the SmPC, selegiline can be given alone early in the illness to ease symptoms and put off the need for levodopa, or added to levodopa (with or without a decarboxylase inhibitor). It is particularly useful for people on maximal levodopa treatment whose control fluctuates, for example with end-of-dose wearing off or sudden on-off swings.

Two strengths are available here: 5 mg tablets in packs of 30, 60, 90, 120, 180, 240 or 360, and 10 mg tablets in packs of 30, 60, 90, 120 or 240. Eldepryl is a brand licensed in the UK, with 5 mg and 10 mg tablets held by Orion Corporation, and selegiline is a prescription-only medicine (POM). It is important to be clear which strength has been prescribed, because the daily dose should not exceed 10 mg.

The SmPC gives a dose of 10 mg a day, whether selegiline is used alone or alongside levodopa. It can be taken as one dose in the morning or split into two 5 mg doses at breakfast and lunch. When selegiline is added to existing levodopa treatment, the levodopa dose can often be lowered by an average of 10 to 30 per cent, reducing it gradually in 10 per cent steps every three to four days, as the combination may otherwise cause involuntary movements and agitation. No adjustment is needed for kidney or liver impairment. Above 10 mg daily, selegiline starts to lose its selectivity, and there is a theoretical risk of a sharp rise in blood pressure after eating tyramine-rich foods.

This is the area that needs the closest attention. Selegiline must not be taken with any type of antidepressant, including SSRIs such as citalopram, sertraline and fluoxetine, SNRIs such as venlafaxine, tricyclics and other MAO inhibitors, because severe reactions of the serotonin syndrome type, some of them fatal, have been reported. Triptans for migraine, pethidine and other opioids, linezolid and sympathomimetic decongestants are also excluded. After stopping fluoxetine, at least five weeks should pass before selegiline is started; the gap is two weeks after sertraline and one week after other SSRIs. In the other direction, 14 days are needed after the last dose of Eldepryl before an interacting medicine is begun. Alcohol should be avoided, and an anaesthetist must be told about treatment before any operation.

Selegiline is unsuitable for people with an active stomach or duodenal ulcer, or with movement disorders that are not caused by dopamine deficiency. When it is combined with levodopa, the SmPC also excludes severe heart disease, high blood pressure, an overactive thyroid, phaeochromocytoma, narrow-angle glaucoma, prostate enlargement with residual urine, a fast or irregular heartbeat, severe angina, psychosis and advanced dementia. Extra caution applies with unstable blood pressure, a history of peptic ulcers and liver or kidney problems. It is preferably avoided in pregnancy and should not be used while breastfeeding.

Mouth inflammation (stomatitis) is very common. Common effects include nausea, constipation, diarrhoea, mouth ulcers, dizziness, headache, vertigo, disturbed sleep, confusion, hallucinations, low mood, a slow pulse, high or low blood pressure, joint and back pain, muscle cramps and falls. Involuntary movements are also common, especially alongside levodopa. Some people taking dopaminergic medicines develop impulse control problems such as compulsive gambling, shopping or eating, and family members should know to look out for this. As Eldepryl can cause dizziness, it may affect driving. Whether selegiline is right for someone, and in what dose, is for the prescriber to decide.