Drug Interactions between medroxyprogesterone and st. john's wort
This report displays the potential drug interactions for the following 2 drugs:
- medroxyprogesterone
- st. john's wort
Interactions between your drugs
medroxyPROGESTERone St. John's wort
Applies to: medroxyprogesterone and st. john's wort
MONITOR: Coadministration with inducers of CYP450 3A4 may decrease the plasma concentrations and pharmacologic effects of medroxyprogesterone, which is primarily metabolized by the isoenzyme. Aminoglutethimide, a CYP450 3A4 inducer, has been shown to significantly decrease the serum levels of medroxyprogesterone by 50% or more when administered at 250 mg two to four times daily to women with breast cancer receiving high-dose medroxyprogesterone orally. The decrease was accompanied by an increase in serum cortisol level, which suggests diminished adrenal suppressive effect of medroxyprogesterone. The interaction has not been studied with depot formulations of medroxyprogesterone. Because the clearance of medroxyprogesterone is approximately equal to the rate of hepatic blood flow, drugs that induce CYP450 3A4 are not expected to significantly affect the pharmacokinetics of medroxyprogesterone administered parenterally. In one study, no interaction was reported when medroxyprogesterone was administered intravenously with aminoglutethimide.
MANAGEMENT: Pharmacologic response to medroxyprogesterone should be monitored more closely whenever a CYP450 3A4 inducer is added to or withdrawn from therapy, and the dosage adjusted as necessary. When administered as the depot formulation for contraception, no dosage adjustment for medroxyprogesterone is currently recommended during coadministration with CYP450 3A4 inducers. However, consideration may be given to decreasing the dosing interval (e.g., from one injection every 12 weeks to every 10 weeks) if an interaction is suspected.
References (7)
- Lundgren S, Lonning PE, Aakvaag A, Kvinnsland S, Lnning PE (1990) "Influence of aminoglutethimide on the metabolism of medroxyprogesterone acetate and megestrol acetate in postmenopausal patients with advanced breast cancer." Cancer Chemother Pharmacol, 27, p. 101-5
- Halpenny O, Bye A, Cranny A, Feely J, Daly PA (1990) "Influence of aminoglutethimide on plasma levels of medroxyprogesterone acetate." Med Oncol Tumor Pharmacother, 7, p. 241-7
- (2001) "Product Information. Depo-Provera (medroxyprogesterone)." Pharmacia and Upjohn
- (2001) "Product Information. Provera (medroxyprogesterone)." Pharmacia and Upjohn
- Kobayashi K, Mimura N, Fujii H, et al. (2000) "Role of human cytochrome P450 3A4 in metabolism of medroxyprogesterone acetate." Clin Cancer Res, 6, p. 3297-303
- (2005) "FFPRHC Guidance (April 2005). Drug interactions with hormonal contraception." J Fam Plann Reprod Health Care, 31, p. 139-51
- O'Brien MD, Guillebaud J (2006) "Contraception for women with epilepsy." Epilepsia, 47, p. 1419-22
Drug and food interactions
St. John's wort food
Applies to: st. john's wort
GENERALLY AVOID: An isolated case report suggests that foods containing large amounts of tyramine may precipitate a hypertensive crisis in patients treated with St. John's wort. The mechanism of interaction is unknown, as St. John's wort is not thought to possess monoamine oxidase (MAO) inhibiting activity at concentrations achieved in vivo. The case patient was a 41-year-old man who had been taking St. John's wort for seven days prior to presentation at the emergency room with confusion and disorientation. The patient recalled last eating aged cheese and having a glass of red wine approximately 10 hours prior to admission. No other cause of delirium or hypertension could be identified. In addition, alcohol may potentiate some of the pharmacologic effects of St. John's wort. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: Until further information is available, patients treated with St. John's wort should consider avoiding consumption of protein foods in which aging or breakdown of protein is used to increase flavor. These foods include cheese (particularly strong, aged or processed cheeses), sour cream, wine (particularly red wine), champagne, beer, pickled herring, anchovies, caviar, shrimp paste, liver (particularly chicken liver), dry sausage, figs, raisins, bananas, avocados, chocolate, soy sauce, bean curd, yogurt, papaya products, meat tenderizers, fava beans, protein extracts, and dietary supplements. Caffeine may also precipitate hypertensive crisis so its intake should be minimized as well. Patients should also be advised to avoid or limit consumption of alcohol.
References (1)
- Patel S, Robinson R, Burk M (2002) "Hypertensive crisis associated with St. John's Wort." Am J Med, 112, p. 507-8
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
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