Oral contraceptives interaction

Krieger C, Jones K, Kim SU, et al The role of intracellular free calcium in motor-neuron disease. J Neurol Sci 124 27-32, 1994 Kroboth PD, Smith RB, Stoehr GP, et al Pharmacodynamic evaluation of the benzodiazepine—oral contraceptive interaction. Chn Pharmacol Ther 38 525-532, 1985... 

Deray G, le Hoang P, Cacoub P, Assogba U, Grippon P, Baumelou A. Oral contraceptive interaction with cyclosporin. Lancet 1987 l(8525) 158-9. 

Krobodi PD, Smidi RB, Stoehr GP, Juhl RP. Pharmacocfynamic evaluation of the benzodi-azepine-oral contraceptive interaction. Clin Pharmacol 7%er(1985) 38, 525-32. 

Krauss GL, Brandt J, Campbell M, Plate C, Summerfield M. Antiepileptic medication and oral contraceptive interactions a national survey of neurologists and obstetricians. Neurology (1996)46,1534-9. 

Saw palmetto (cabbage palm, fan palm, scrub palm) Serenoa repens %mptoms of benign prostatic hyperplasia Generally well-tolerated occasional gastrointestinal effects May interact with hormones such as oral contraceptive drugs and hormone replacement therapy. 

Is there an interaction between carbamazepine and the oral contraceptive ... 

Drug Interactions Carbamazepine induces the hepatic metabolism of many drugs, including other antiepileptic drugs, antipsychotics, some antidepressants, oral contraceptives, and... 

Cite important drug interactions with oral contraceptives. 

Ethinyl estradiol is metabolized in the liver via the cytochrome P-450 system. It is metabolized primarily via CYP450 3A4. When reviewing drug interactions of oral contraceptives, it is important to keep in mind that antibiotic administration during contraceptive use may decrease the efficacy of many combined contraceptives. Refer to Table 45-4 for a list of common drug interactions seen with oral contraceptives.1,31... 

Dickinson BD, Altman RD, Nielsen NH, Sterling ML Council on Scientific Affairs, American Medical Association Drug interactions between oral contraceptives and antibiotics. Obstet Gynecol 2001 98 853-860. 

Numerous potential drug interactions are possible clinically significant drug interactions with oral contraceptives, warfarin, and oral dexametha-sone have been described. 

Interactions of Oral Contraceptives (PCs) with Other Drugs... 

Drug-drug interactions are often more problematic with carbamazepine than other mood stabilizers. Carbamazepine increases the activity of certain liver enzymes. Because these enzymes metabolize and eliminate medications and other substances introduced to the body, carbamazepine therapy can decrease the blood level and thereby reduce the effectiveness of itself (a phenomenon called autoinduction) and other medications that are metabolized by these enzymes. It is not unusual to find that the dose of carbamazepine must be increased after several weeks, because it has increased its own elimination. Other medications may likewise be less effective. Of particular concern are the oral contraceptives, Depo-Provera, and protease inhibitors used for the treatment of HI V+ patients. Oral contraceptives often require an increase in dose. 

Corbamazepine interacts with oral contraceptives. Corbamazepine increases the metabolism of oestrogens and progestogens resulting in a decrease in the plasma concentration of oestrogens and progestogens. This in turn brings about a decrease in the contraceptive level provided. 

Drugs that may interact with folic acid include aminosalicylic acid, oral contraceptives, dihydrofolate reductase inhibitors (eg, methotrexate, trimethoprim), sulfasalazine, hydantoins. 

Drugs that may be affected by HMG-CoA reductase inhibitors include oral contraceptives, diclofenac, digoxin, glyburide, phenytoin, and warfarin. Atorvastatin, lovastatin, and simvastatin are primarily metabolized by CYP3A4 they may interact with CYP3A4 inhibitors. 

Drug interactions with tizanidine hydrochloride include acetaminophen, alcohol, and oral contraceptives. 

Tegaserod may interact with digoxin and oral contraceptives. 

Prescribers are advised to consult the package insert of any medication administered concomitantly with hormonal contraceptives, because some medications may decrease the effectiveness of these birth control products. Patients should be prospectively cautioned not to self-medicate with the herbal supplement St. John s wort because a possible interaction has been suggested with hormonal contraceptives based on reports of breakthrough bleeding while on oral contraceptives shortly after starting St. John s wort. Pregnancies have been reported by users of combined hormonal contraceptives who also used some form of St. John s wort. 

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