Eldepryl (selegiline hydrochloride) for Parkinson’s disease

Last updated Oct. 31, 2023, by Marisa Wexler, MS
Fact-checked by Ana de Barros, PhD

What is Eldepryl for Parkinson’s disease?

Eldepryl (selegiline hydrochloride), now discontinued in the U.S., was an approved add-on therapy given in addition to standard levodopa and carbidopa treatment to help manage off episodes, or motor fluctuations, in Parkinson’s disease patients.

It was developed by Somerset Pharmaceuticals, but was discontinued in the U.S. and other markets. According to the U.S. Food and Drug Administration (FDA), the discontinuation of Eldepryl was not related to its safety or efficacy.

Therapy snapshot

How does Eldepryl work?

Parkinson’s is caused by the death and dysfunction of cells in the brain that are responsible for making dopamine, a chemical messenger that nerve cells use to communicate with each other. A lack of dopamine signaling ultimately gives rise to Parkinson’s symptoms. Levodopa in combination with carbidopa is a standard treatment that works to provide more raw materials with which to make dopamine.

Eldepryl works by blocking the activity of monoamine oxidase B (MAO-B), an enzyme that normally breaks down dopamine in the brain. By inhibiting this enzyme, Eldepryl helps dopamine stick around longer in the brain, allowing levodopa and carbidopa to give a bigger boost to dopamine signaling.

Who could take Eldepryl?

In the U.S., Eldepryl was indicated as an adjunct (add-on) treatment to levodopa and carbidopa in people with Parkinson’s who were not responding as well to them as they had been.

According to the FDA label for Eldepryl, there is no adequate clinical evidence to support the use of Eldepryl in the absence of levodopa and carbidopa.

Who should not take Eldepryl?

People with a known allergy to selegiline, the active agent in Eldepryl, should take this drug.

People treated with the opioid meperidine (sold as Demerol) shouldn’t take Eldepryl, and it was generally recommended that Eldepryl shouldn’t be combined with any opioid.

Eldepryl also should not have been used in combination with certain medications to manage depression, namely tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (sold as Prozac).

It should not have been used along with other selegiline products such as Zelapar.

How was Eldepryl administered in Parkinson’s?

Eldepryl was available in aqua blue capsules each containing 5 mg of the medication. Capsules were imprinted with the Somerset logo on the cap and “Eldepryl 5 mg” on the body.

The FDA-approved dosing schedule was one 5 mg tablet with breakfast and another 5 mg tablet at lunch, for a total dosage of 10 mg per day.

Patients were advised that the daily recommended dose of 10 mg not be exceeded and that levodopa might have needed to be reduced after starting Eldepryl.

Eldepryl in clinical trials

The FDA’s approval of Eldepryl was based on data from clinical trials that tested the therapy against a placebo in people with Parkinson’s disease who were on levodopa and carbidopa treatment. According to the therapy’s label, results showed Eldepryl outperformed a placebo on measures of patient-rated effectiveness and led to a greater reduction in off time, that is, when symptoms aren’t adequately controlled between levodopa doses. Eldepryl also outperformed a placebo at allowing patients to reduce their dosage of levodopa and carbidopa.

Eldepryl also resulted in other beneficial effects, including reduced end-of-dose akinesia (inability to initiate voluntary muscle movements), decreased tremors and drooling, improved speech and dressing abilities, and lower overall disability.

A 2023 meta-analysis collectively analyzed data from 27 clinical trials that compared selegiline (the therapeutic agent in Eldepryl) against a placebo (usually in addition to levodopa or other treatments), as well as 11 observational studies on the therapy. Analysis of the pooled data at several points from one month to five years showed selegiline was better than a placebo at easing Parkinson’s symptoms, as reflected by lower scores on the Unified Parkinson’s Disease Rating Scale (UPDRS) and other measures.

Common side effects of Eldepryl

Common side effects of Eldepryl included:

• nausea
• dizziness, lightheadedness, or fainting
• abdominal pain
• confusion
• hallucinations
• dry mouth
• vivid dreams
• uncontrolled movements (dyskinesia)
• headache.

Levodopa-associated side effects

Because Eldepryl extended the action of levodopa in the brain, it might have worsened side effects associated with levodopa, such as dyskinesia. These side effects can often be eased by lowering the dose of levodopa and carbidopa by about 10 to 30%.

Abnormal urges

Some patients given medicines like Eldepryl  that increase dopamine signaling experienced intense urges, such as a sudden intense desire to gamble or engage in risky sexual behavior.

Dietary considerations

Consuming a high amount of a molecule called tyramine by people taking MAO inhibitors like Eldepryl could have caused a dangerous increase in blood pressure. Most people who took Eldepryl at the recommended dose didn’t have to limit their intake of tyramine, but there were a few cases of blood pressure problems associated with consuming it.

Patients who have signs of high blood pressure, such as a sudden severe headache or unexpected new symptoms, should contact their healthcare provider immediately.

Melanoma

People with Parkinson’s are at increased risk of the skin cancer melanoma, but to date it remains unclear if this is because of Parkinson’s itself or because of treatments for it. People with Parkinson’s should have regular skin examinations to monitor for melanoma.

Use in pregnancy and breastfeeding

There have not been adequate studies that assessed Eldepryl in people who are pregnant or breastfeeding. The medication could only be used in these situations if the potential benefit from treatment clearly outweighted the potential for side effects.

Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.