Venlafaxine

Also indexed as: Effexor®

Venlafaxine is a drug used to treat depression. It is unrelated to other drugs used to treat depression.

Safetychecker Summary for Venlafaxine
(for details about the summarized interactions, read the full article)

Avoid Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results.

5-Hydroxytryptophan (5-HTP)*

L-tryptophan*

St. John’s wort*
Check Check: Other—Before taking any of these supplements or eating any of these foods with your medication, read this article in full for details.

Sodium
Depletion or interference

None known
Side effect reduction/prevention

None known
Supportive interaction

None known
Reduced drug absorption/bioavailability

None known

An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.

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.

Interactions with Herbs

St. John’s wort (Hypericum perforatum)
Although there have been no interactions reported in the medical literature, it is best to avoid using venlafaxine with St. John’s wort unless you are under the supervision of a qualified healthcare professional.

Interactions with Foods and Other Compounds

Food
Venlafaxine is recommended to be taken with food.6

Alcohol
Venlafaxine may cause dizziness or drowsiness.7 Alcohol may intensify these effects and increase the risk of accidental injury.8 To prevent problems, people taking venlafaxine should avoid alcohol.

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.