Selegiline

Brand names

• Apo-Selegiline
• Carbex
• Dom-Selegiline
• Eldepryl
• Gen-Selegiline
• Novo-Selegiline
• Nu-Selegiline
• PMS-Selegiline

Usage

To treat Parkinson's disease, in conjunction with levodopa /carbidopa. May be used alone early in Parkinson's disease, to delay the need for levodopa.

How it works

When used with levodopa /carbidopa, selegiline allows more levodopa/ carbidopa to be available for use in the body by inhibiting a nervous system enzyme called monoamine oxidase (MAO). MAO, which is found in the brain and intestinal tract, acts to break down certain chemicals that play a role in the initiation and control of muscle movement.

Side effects

Serious

Dizziness, low blood pressure (causing dizziness, lightheadedness, fainting, or confusion), involuntary muscle movements, heart rhythm abnormalities, severe headache.

Common

Nausea, dry mouth.

Less common

Palpitations, drowsiness, hallucinations.

Possible interactions

Other medicaments:

Selegiline taken concurrently with:

• albuterol (Ventolin, others) may result in increased adverse vascular effects.
• amphetamine (Dexedrine) can cause a severe increase in blood pressure.
• antidepressants such as amitriptyline (Elavil) may cause neurotoxic reactions such as seizures.
• antihypertensive medicaments (and other medicaments that can lower blood pressure) require careful monitoring for excessive drops in pressure; dose adjustments may be necessary.
• benzodiazepines may result in increased central nervous system depression.
• birth control pills (oral contraceptives) may increase risk of selegiline toxicity.
• bupropion (Wellbutrin) may cause seizures.
• buspirone (Buspar) may result in increases in blood pressure.
• carbamazepine (Tegretol) may result in high fevers and seizures-still, some studies found benefits in resistant depression.
• citalopram (Celexa) may lead to toxicity.
• cyclobenzaprine (Flexeril) may lead to toxicity.
• dextromethorphan (various), a cough suppressant used in many nonprescription cough medicines, has been reported to cause toxicity with low blood pressure, spasms, high fevers and some deaths-these medicines should not be combined.
• ephedrine (various) can result in severe increases in temperature.
• fluoxetine (Prozac) may cause serotonin toxicity syndrome.
• fluvoxamine (Luvox) may result in extreme agitation, rigidity, excessive temperatures and coma.
• lithium (Lithobid) may increase risk of the serotonin toxicity syndrome.
• meperidine (Demerol) may cause a life-threatening reaction of unknown cause; avoid this combination.
• methyldopa (Aldomet) may lead to hypertensive crisis.
• mirtazapine (Remeron) may lead to adverse seizures.
• morphine (MS Contin, various) may lead to excessive CNS and lowered blood pressure effects.
• nefazodone (Serzone) may lead to serotonin syndrome.
• oral hypoglycemic agents may cause very low blood sugars.
• paroxetine (Paxil) may result in central nervous system toxicity.
• phenothiazines may result in increased occurrence of movement disorders.
• phentermine (Fastin) may lead to hypertensive crisis.
• phenylpropanolamine (various) or phenylephrine (various) can cause severe increases in temperature and blood pressure.
• pseudoephedrine (various) can cause severe increases in temperature and blood pressure.
• sertraline (Zoloft) may result in central nervous system toxicity.
• sibutramine (Meridia) may lead to toxicity.
• sumatriptan (Imitrex) may lead to toxicity.
• tramadol (Ultram) may lead to seizures.
• tryptophan may cause a fatal serotonin syndrome.
• venlafaxine (Effexor) can result in central and autonomic nervous system toxicity.

The following medicaments may decrease the effects of selegiline and diminish its effectiveness:

• chlorprothixene (Taractan).
• haloperidol (Haldol).
• metoclopramide (Reglan).
• phenothiazines.
• reserpine (Ser-Ap-Es, etc.). in high doses.
• thiothixene (Navane).

Foods:

Caution should be used regarding foods containing tyramine, although the reaction with this medicament may not be as severe as that seen with other MAO inhibitors.

Herbal medicines or minerals:

St. John's wort: caution is advised because of possible serotonin syndrome. St. John's wort may also worsen sensitivity to the sun. Since part of the way ginseng works may be as an MAO inhibitor, do not combine ginseng with selegiline. Ma huang and yohimbe are also best avoided while taking this medicine. Calabar bean (chop nut, fabia, ordeal nut, others) is unsafe when taken by mouth (physostigmine is the active ingredient) and should never be taken by people with Parkinson's disease. Octacosanol (a cousin of vitamin E) can worsen movement problems and should also be avoided.

Alcohol:

Use caution until the combined effects have been determined. Alcohol may exaggerate the blood-pressure-lowering and sedative effects of this medicament. Aged wines, etc., containing tyramine may cause a reaction of varying severity.

Marijuana smoking:

Additive drowsiness may occur.

Exposure to sun:

Use caution-photosensitivity has been reported.

Exposure to heat:

Use caution until the combined effects have been determined. Hot environments can cause lowering of blood pressure.

Discontinuation:

Do not stop this medicament abruptly. Sudden withdrawal can cause prompt increase in Parkinsonian symptoms and deterioration of control. Consult your physician regarding a schedule for gradual withdrawal and concurrent adjustment of Sinemet or other appropriate medicaments.

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