Paroxetine

Also indexed as: Paxil®, Seroxat®

Paroxetine is a member of the selective serotonin reuptake inhibitor (SSRI) family of drugs used to treat people with depression.

Summary of Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem contradictory. For clarification, read the full article for details about the summarized interactions.

Beneficial May be Beneficial: Depletion or interference—The medication may deplete or interfere with the absorption or function of the nutrient. Taking these nutrients may help replenish them.

Sodium
Beneficial May be Beneficial: Side effect reduction/prevention—Taking these supplements may help reduce the likelihood and/or severity of a potential side effect caused by the medication.

Ginkgo biloba*
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*
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-trytophan
Paroxetine increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with paroxetine may increase paroxetine-induced side effects. Dietary supplements of L-tryptophan (available only by prescriptions from special compounding pharmacists) taken with paroxetine caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.1 Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase the effectiveness of the latter. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with paroxetine or other SSRIs, unless the combination is being closely monitored by a doctor. Foods rich in L-tryptophan do not appear to interact with paroxtine or other SSRIs.

On the other hand, the combination of 45 mg DL-tryptophan (a synthetic variation of L-tryptophan) per pound of body weight (a relatively high dose) with zimelidine, a drug with a similar action to paroxetine, did not cause these side effects in another trial.2

Sodium
SSRI drugs, including paroxetine, have been reported to cause sodium depletion.3 4 5 The risk for SSRI-induced sodium depletion appears to be increased during the first few weeks of treatment in women, the elderly, and patients also using diuretics. Doctors prescribing SSRI drugs, including paroxetine, should monitor their patients for signs of sodium depletion.

Interactions with Herbs

Ginkgo biloba
In three men and two women treated with fluoxetine or sertraline (SSRI drugs closely related to paroxetine) for depression who experienced sexual dysfunction, addition of Ginkgo biloba extract (GBE) in the amount of 240 mg per day effectively reversed the sexual dysfunction.6 This makes sense because ginkgo has been reported to help men with some forms of erectile dysfunction.7

St. John’s wort (Hypericum perforatum)
One report described a case of serotonin syndrome in a patient who took St. John’s wort and trazodone, a weak SSRI drug.8 The patient reportedly experienced mental confusion, muscle twitching, sweating, flushing, and ataxia. In another case, a patient experienced grogginess, lethargy, nausea, weakness, and fatigue after taking one dose of paroxetine after ten days of St. John’s wort use.9

Interactions with Foods and Other Compounds

Food
Paroxetine may be taken with or without food.10

Alcohol
SSRI drugs, including paroxetine, may cause dizziness or drowsiness.11 Alcohol may intensify these effects and increase the risk of accidental injury. Alcohol should be avoided during paroxetine therapy.

References

1. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264q–4r.

2. Walinder J, Carlsson A, Persson R. 5-HT reuptake inhibitors plus tryptophan in endogenous depression. Acta Psych Scand Suppl 1981;290:179–90.

3. Spigset O, Hedenmalm K, Mortimer O. Hyponatremia as a side effect of serotonin uptake inhibitors. Lakartidningen 1998;95:3537–9 [Swedish].

4. Strachan J, Shepherd J. Hyponatraemia associated with the use of selective serotonin re-uptake inhibitors. Aust N Z J Psychiatry 1998;32:295–8.

5. Bouman WP, Pinner G, Johnson H. Incidence of selective serotonin reuptake inhibitor (SSRI) induced hyponatraemia due to the syndrome of antidiuretic hormone (SIADH) secretion in the elderly. Int J Geriatr Psychiatry 1998;13:12–5.

6. Cohen AJ. Long term safety and efficacy of Ginkgo biloba extract in the treatment of anti-depressant-induced sexual dysfunction. Psychiatry On-Line http://www.priory.com/ginkgo.html.

7. Sohn M, Sikora R. Ginkgo biloba extract in the therapy of erectile dysfunction. J Sex Educ Ther 1991;17:53–61.

8. Demott K. St. John’s wort tied to serotonin syndrome. Clinical Psychiatry News 1998;26:28.

9. Gordon JB. SSRIs and St. John’s Wort: possible toxicity? Am Fam Physician 1998;57:950.

10. Nemeroff CB. Paroxetine: an overview of the efficacy and safety of a new selective serotonin reuptake inhibitor in the treatment of depression. J Clin Psychopharmacol 1993;13(6 suppl 2):10S–7S [review].

11. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264q–4r.