Drug Interactions:
Tricyclic Antidepressants

For many years, the tricyclics were the most popular antidepressants. Although superseded today by the less side-effect prone SSRI drugs (Prozac family), they are still used in certain cases.

Antidepressants in this family include

• amitriptyline hydrochloride (Elavil)
• amoxapine (Asendin)
• clomipramine hydrochloride (Anafranil)
• desipramine hydrochloride (Norpramin)
• doxepin hydrochloride (Sinequan)
• imipramine (Tofranil)
• nortriptyline hydrochloride (Aventyl, Pamelor)
• protriptyline hydrochloride (Vivactil)
• trimipramine maleate (Surmontil)
• and others

Coenzyme Q10 (CoQ10)

Supplementation Possibly Helpful

Preliminary evidence suggests that tricyclic antidepressants might deplete the body of coenzyme Q₁₀ (CoQ₁₀), a substance that appears to be important for normal heart function.^1,2 Based on this observation, it has been suggested (but not proved) that CoQ₁₀ supplementation might help prevent the heart-related side effects that can occur with the use of tricyclic antidepressants.

St. John's Wort, Yohimbe, 5-HTP (5-Hydroxytryptophan), SAMe (S-Adenosylmethionine)

Possible Dangerous Interactions

Based on one case report³ and our general knowledge about the actions of these supplements, taking any of these in combination with some tricyclic antidepressants could conceivably present a risk of elevating serotonin levels too high.

St. John's Wort

Possible Harmful Interaction

St. John’s wort might decrease the effectiveness of tricyclic antidepressants by reducing blood levels of the drug.⁴ Conversely, if you are taking St. John's wort already and your physician adjusts your dose of medication, suddenly stopping the herb could cause blood levels of the drug to rise dangerously high.

Last reviewed March 2002 by Medical Review Board

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