"What are birth control pills and how do they work?
Birth control pills are also known as oral contraceptives (OCs) or, simply, “the pill.” They offer protection against pregnancy by blocking the union of sperm and egg, thereby prevent"...
An increased risk of the following serious adverse reactions has been associated with the use of oral contraceptives (see WARNINGS section):
| • Thrombophlebitis and venous
thrombosis with or without embolism
• Arterial thromboembolism
• Pulmonary embolism
• Myocardial infarction
| • Cerebral hemorrhage
• Cerebral thrombosis
• Gallbladder disease
• Hepatic adenomas or benign liver tumors
There is evidence of an association between the following conditions and the use of oral contraceptives:
|• Mesenteric thrombosis||• Retinal thrombosis|
The following adverse reactions have been reported in patients receiving oral contraceptives and are believed to be drug-related:
| • Nausea
• Gastrointestinal symptoms (such as
abdominal pain, cramps and bloating)
• Breakthrough bleeding
• Change in menstrual flow
• Temporary infertility after
discontinuation of treatment
• Edema/fluid retention
• Melasma/chloasma which may persist
• Breast changes: tenderness, pain,
enlargement, and secretion
• Decrease in serum folate levels
• Exacerbation of porphyria
• Aggravation of varicose veins
| • Change in weight or appetite (increase or decrease)
• Change in cervical ectropion and secretion
• Possible diminution in lactation when given
• Cholestatic jaundice
• Migraine headache
• Rash (allergic)
• Mood changes, including depression
• Vaginitis, including candidiasis
• Change in corneal curvature (steepening)
• Intolerance to contact lenses
• Exacerbation of systemic lupus erythematosus
• Exacerbation of chorea
• Anaphylactic/anaphylactoid reactions, including urticaria, angioedema, and severe reactions with respiratory and circulatory symptoms
The following adverse reactions have been reported in users of oral contraceptives and the association has been neither confirmed nor refuted:
| • Pre-menstrual syndrome
• Cystitis-like syndrome
• Loss of scalp hair
• Erythema multiforme
| • Erythema nodosum
• Hemorrhagic eruption
• Impaired renal function
• Hemolytic uremic syndrome
• Changes in libido
• Budd-Chiari Syndrome
• Optic neuritis, which may lead to partial or complete loss of vision
Read the Cyclessa (desogestrel ethinyl estradiol tablets) Side Effects Center for a complete guide to possible side effects
Changes in contraceptive effectiveness associated with co-administration of other drugs:
a. Anti-infective agents and anticonvulsants
Contraceptive effectiveness may be reduced when hormonal contraceptives are co-administered with some antibiotics, anticonvulsants, and other drugs that increase metabolism of contraceptive steroids. This could result in unintended pregnancy or breakthrough bleeding. Examples include barbiturates, rifampin, phenylbutazone, phenytoin, carbamazepine, felbamate, oxcarbazepine, topiramate, and griseofulvin.
Since desogestrel is mainly metabolized by the cytochrome P450 2C9 enzyme (CYP 2C9) to form etonogestrel, the active progestin, there is a possibility of interaction with CYP 2C9 substrates or inhibitors (such as: ibuprofen, piroxicam, naproxen, phenytoin, fluconazole, diclofenac, tolbutamide, glipizide, celecoxib, sulfamethoxazole, isoniazid, torsemide, irbesartan, losartan, and valsartan). The clinical relevance of these interactions is unknown.
b. Anti-HIV protease inhibitors
Several of the anti-HIV protease inhibitors have been studied with co-administration of oral combination hormonal contraceptives; significant changes (increase and decrease) in the plasma levels of the estrogen and progestin have been noted in some cases. The efficacy and safety of these oral contraceptive products may be affected with co-administration of anti-HIV protease inhibitors. Health care providers should refer to the label of the individual anti-HIV protease inhibitors for further drug-drug interaction information.
c. Herbal products
Herbal products containing St. John's Wort (hypericum perforatum) may induce hepatic enzymes (cytochrome P450) and p-glycoprotein transporter and may reduce the effectiveness of contraceptive steroids. This may also result in breakthrough bleeding.
Increase in plasma hormone levels associated with co-administered drugs
Co-administration of atorvastatin and certain ethinyl estradiol containing oral contraceptives increased AUC values for ethinyl estradiol by approximately 20%. Ascorbic acid and acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. CYP 3A4 inhibitors such as itraconazole or ketoconazole may increase plasma hormone levels.
Changes in plasma levels of co-administered drugs
Combination hormonal contraceptives containing some synthetic estrogens (e.g., ethinyl estradiol) may inhibit the metabolism of other compounds. Increased plasma concentrations of cyclosporine, prednisolone, and theophylline have been reported with concomitant administration of oral contraceptives. Decreased plasma concentrations of acetaminophen and increased clearance of temazepam, salicylic acid, morphine and clofibric acid have been noted when these drugs were administered with oral contraceptives.
No formal drug-drug interaction studies were conducted with Cyclessa® (desogestrel ethinyl estradiol tablets) .
Interactions With Laboratory Tests
Certain endocrine and liver function tests and blood components may be affected by oral contraceptives:
b. Increased thyroid binding globulin (TBG) leading to increased circulating total thyroid hormone, as measured by protein-bound iodine (PBI), T4 by column or by radioimmunoassay. Free T3 resin uptake is decreased, reflecting the elevated TBG; free T4 concentration is unaltered.
c. Other binding proteins may be elevated in serum.
d. Sex hormone-binding globulins are increased and result in elevated levels of total circulating sex steroids; however, free or biologically active levels either decrease or remain unchanged.
f. Glucose tolerance may be decreased.
g. Serum folate levels may be depressed by oral contraceptive therapy. This may be of clinical significance if a woman becomes pregnant shortly after discontinuing oral contraceptives.
Last reviewed on RxList: 5/2/2007
This monograph has been modified to include the generic and brand name in many instances.
Additional Cyclessa Information
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