Drug Information
Summary of Interactions with Vitamins, Herbs, & Foods
Types of interactions:BeneficialAdverseCheck
Replenish Depleted Nutrients
- Vitamin B6
Phenelzine has a chemical structure similar to other drugs (isoniazid and hydralazine) that can cause vitamin B6 deficiency. One case of phenelzine-induced vitamin B6 deficiency has been reported. Little is known about this interaction. People taking phenelzine should ask their doctor about monitoring vitamin B6 levels and considering supplementation.
Support Medicine
- L-Tryptophan
Both L-tryptophan and 5-HTP have been used to treat depression. One controlled study showed that taking selegiline at the same time as 5-HTP enhanced the antidepressant effect when compared with 5-HTP alone. Further research is needed to determine whether taking selegiline and 5-HTP together might result in unwanted side effects.
Potential Negative Interaction
Ephedrine is an active ingredient found in ephedra, an herb that until 2004 was used in cold remedies and herbal weight loss products. One individual taking selegiline together with ephedrine experienced a serious side effect known as hypertensive crisis, in which blood pressure can reach dangerous levels. Though no studies have investigated whether the herb ephedra might result in similar effects, the current evidence suggests that people taking selegiline should avoid all products that contain ephedra.
Scotch broom contains high levels of tyramine. Combining phenelzine and Scotch broom may cause MAOI-type reactions (diarrhoea, flushing, sweating, pounding chest, dangerous changes in blood pressure, and other symptoms). It is important for people taking phenelzine to avoid Scotch broom. People with questions about phenelzine and Scotch broom should ask their doctor.
Explanation Required
Rarely, people taking selegiline might experience a rapid rise in blood pressure and a severe throbbing headache when the drug is taken with foods that contain tyramine, such as cheese (especially aged); sour cream; yogurt; alcoholic beverages; meat, fish, and poultry; a variety of fruits and vegetables, including avocados, figs, and eggplant; fava beans; some soups; and chocolate. One study showed that taking 30 mg of selegiline each day greatly increases tyramine sensitivity. It has therefore been suggested that people taking 30 mg or more of selegiline per day should consume a tyramine-free diet.
- 5-HTP
Both L-tryptophan and 5-HTP have been used to treat depression. One controlled study showed that taking selegiline at the same time as 5-HTP enhanced the antidepressant effect when compared with 5-HTP alone. Further research is needed to determine whether taking selegiline and 5-HTP together might result in unwanted side effects.
The interaction is supported by preliminary, weak, fragmentary, and/or contradictory scientific evidence.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
