Interactions with Dietary Supplements
5-Hydroxytryptophan (5-HTP) and
L-tryptophan
Venlafaxine, a potent serotonin reuptake inhibitor, has been associated with several cases of
serotonin syndrome.1 2 3 4 5-HTP and L-tryptophan
are converted to serotonin in the brain, and taking them with venlafaxine may increase
venlafaxine-induced side effects. While no interactions with venlafaxine and 5-HTP or
L-tryptophan have been reported, until more is known, people taking venlafaxine are cautioned
to avoid 5-HTP or L-tryptophan.
Sodium
One case was reported of a 79-year-old woman with depression treated with venlafaxine who
experienced hyponatremia (abnormally low blood levels of sodium).5 It remains
unclear whether this interaction has any but rare ramifications.
References
1. Brubacher JR, Hoffman RS, Lurin MJ. Serotonin syndrome from
venlafaxine-tranylcypromine interaction. Vet Hum Toxicol 1996;38:358–61.
2. Weiner LA, Smythe M, Cisek J. Serotonin syndrome secondary to
phenelzine-venlafaxine interaction. Pharmacotherapy 1998;18:399–403.
3. Bhatara VS, Magnus RD, Paul KL, Preskorn SH. Serotonin syndrome
induced by venlafaxine and fluoxetine: a case study in polypharmacy and potential
pharmacodynamic and pharmacokinetic mechanisms. Ann Pharmacother
1998;32:432–6.
4. Diamond S, Pepper BJ, Diamond ML, et al. Serotonin syndrome induced by
transitioning from phenelzine to venlafaxine: four patient reports. Neurology
1998;51:274–6.
5. Ranieri P, Franzoni S, Rozzini R, Trabucchi M. Venlafaxine-induced
reset osmostat syndrome: case of a 79-year-old depressed woman. J Geriatr Psychiatry
Neurol 1997;10:75–8.
6. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants,
Venlafaxine. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Mar 1995, 263r–3x.
7. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants,
Venlafaxine. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Mar 1995, 263r–3x.
8. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants,
Venlafaxine. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and
Comparisons, Mar 1995, 263r–3x.
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