Jumex™
[Selegiline HCl]
Description / Properties
Selegiline is a selective MAO-B inhibitor, which prevents dopamine breakdown in the brain. It also inhibits the re-uptake of dopamine at the presynaptic dopamine receptor. These effects potentiate dopaminergic function in the brain and help to even out and prolong the effect of exogenous or endogenous dopamine.
Recent studies have demonstrated that use of selegiline in previously untreated patients can delay the development of disability and prolong the time before levodopa therapy is required.
Selegiline potentiates and prolongs the effect of levodopa in the treatment of parkinsonism. The addition of selegiline to levodopa (with or without decarboxylase inhibitor) therapy helps to alleviate dose-related fluctuation and end-of-dose deterioration. At a later stage in the disease it can also smooth the symptoms of the on/off effect.
Selegiline is not intended for use in patients with extra-pyramidal syndromes not accompanied by dopamine deficiency (essential tremor, Huntington’s chorea).
Selegiline when administered orally is characterized by a rapid and extensive absorption. Selegiline is rapidly distributed and metabolized in the human body. The main metabolites found are 1-methamphetamine, 1-amphetamine and N-desmethylselegiline. The excretion is predominantly renal (about 73 % of the administered dose is excreted in the urine in 72 hours).
Indications
Selegiline is indicated for the treatment of Parkinson’s disease or symptomatic parkinsonism.
Selegiline may be used alone in early Parkinson’s disease to delay the need for levodopa (with or without peripheral decarboxylase inhibitor, i.e. PDI). Selegiline may also be used as an adjunct to levodopa (with or without PDI).
Contraindication
Hypersensitivity to selegiline.
Association with selective serotonin reuptake inhibitors (SSRI). Tricyclics antidepressants, sympathomimetics, pethidine (meperidine). (See “ Drug Interactions”).
Drug Interactions
Sympathomimetics:
During selegiline treatment, administration of sympathomimetics should not be used because of the risk of hypertension.
MAO inhibitors:
Concomitant administration of selegiline and MAO inhibitors may cause severe fall in blood pressure.
Pethidine:
The interaction between non-selective MAO inhibitors and pethidine is well known. Although the mechanism of this interaction has not been cleared yet, the concomitant administration of the selective MAO-B inhibitor selegiline and pethidine is contraindicated.
Selective serotonin reuptake inhibitors:
Selegiline should not be used in combination with fluoxetine as agitation, hypertension, convulsions, ataxia, hallucinations and manic psychosis may develop, and fluoxetine should not be used within 14 days of discontinuing therapy with selegiline. Since fluoxetine has a very long elimination half life, at least 5 weeks should be allowed after stopping fluoxetine and before starting selegiline.
Similar experience has been reported in patients receiving selegiline and other specific serotonin reuptake inhibitors (sertraline and paroxetine). Since the mechanisms of these reactions are not fully understood, it is recommended to avoid the combination of selegiline and SSRI.
Tricyclic antidepressants:
Severe central nervous system toxicity (dizziness, tremor, seizures) sometimes associated with hypertension, hypotension, diaphoresis has been occasionally reported in patients with the combination of tricyclic antidepressants and selegiline. Therefore, the concomitant use of selegiline and tricyclic antidepressants is contraindicated.
Food interactions:
Unlike conventional MAO inhibitors, which inhibit both the MAO-A and MAO-B enzymes, selegiline is a specific MAO-B inhibitor.
Foods containing tyramine have not been reported to induce hypertensive reactions during selegiline treatment at recommended dosage (i.e. it does not cause the so-called “cheese-effect”).
However, in case of combination of selegiline and conventional MAO inhibitors or MAO-A, dietary restrictions (i.e. avoidance of food with large amounts of tyramine such as aged cheese and yeast products) are recommended.
Side Effects
When used in monotherapy, selegiline is generally well tolerated ; postural hypotension, nausea, skin reactions, dry mouth, mild transient sleep disturbance, headaches, dizziness, mood change have been reported. Mild increase of liver function enzymes and exceptional cases of urinary retention were described.
Since selegiline potentiates the effect of levodopa, side effects of levodopa (restlessness, hyperkinesis, abnormal movements, agitation, confusion, hallucination, postural hypotension, cardiac arrhythmias, …) may be enhanced in combined therapy (levodopa should be usually given in association with a peripheral decarboxylase inhibitor). Selegiline combination therapy may permit further reduction of levodopa dose (even by 30 per cent).
Warning and Precautions
Because selegiline potentiates the effect of levodopa, the side-effects of levodopa might be emphasized, particularly when the patients are on a very high dosage of levodopa: these patients should be carefully monitored. The addition of selegiline to levodopa may cause involuntary movements and / or agitation. Such side effects disappear when the levodopa dosage is decreased. Levodopa treatment can be reduced by an average of 30 per cent when selegiline is added to the treatment.
Administered at higher doses than those recommended (10 mg), selegiline may loose its MAO-B selectivity and therefore increase the risk of hypertension.
Special care must be taken in patients with gastric or duodenal ulcer, unstable hypertension, arrhythmia, severe angina pectoris or psychosis, as worsening of these preexisting conditions may occur during treatment.
It is recommended that precautions regarding general anesthesia in surgery should be taken in patients receiving MAO inhibitors. (See “Drug Interactions”.)
PREGNANCY AND LACTATION
Selegiline is indicated for parkinsonism. This tends to be a disease of the elderly past child-bearing age. No work has been done to assess the effect of selegiline on pregnancy and lactation, thus it should not be used in such cases.
Dosage
5 to 10 mg daily, either alone or as an adjunct to levodopa or levodopa / PDI. Selegiline may be administered either as a single dose in the morning or in two divided doses taken at breakfast and lunch when the daily dose is 10 mg.
When selegiline is added to a levodopa regimen it is possible to reduce the levodopa dosage by an average of 30 percent.
Presentations Available
Boxes of 50 (5 x10's ALU-ALU blister packed tablets)
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