What are tricyclic antidepressants? How do they interact with other drugs?

Coenzyme Q10 (CoQ10)

Effect: Supplementation Possibly Helpful

Preliminary evidence suggests that tricyclic antidepressants might deplete the body of CoQ10, a substance that appears to be important for normal heart function. 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-Hydroxytryptophan (5-HTP), S-Adenosylmethionine (SAMe)

Effect: Possible Dangerous Interactions

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

St. John’s Wort

Effect: Possible Harmful Interaction

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

Bibliography

Iruela, L. M., et al. “Toxic Interaction of S-Adenosylmethionine and Clomipramine.” American Journal of Psychiatry 150 (1993): 522.

Johne, A., et al. “Decreased Plasma Levels of Amitriptyline and Its Metabolites on Comedication with an Extract from St. John’s Wort (Hypericum perforatum).” Journal of Clinical Psychopharmacology 22 (2002): 46-54.

Roots, J., et al. “Interaction of a Herbal Extract from St. John’s Wort with Amitryptyline and Its Metabolites.” Clinical Pharmacology and Therapeutics 67 (2000): 159.