Continuin
Continuin - General Information
A synthetic progestational hormone used alone or in combination with estrogens as an oral contraceptive.
Pharmacology of Continuin
Continuin is used as a female contraceptive. Continuin is a progestin or a synthetic form of the naturally occurring female sex hormone, progesterone. In a woman's normal menstrual cycle, an egg matures and is released from the ovaries (ovulation). The ovary then produces progesterone, preventing the release of further eggs and priming the lining of the womb for a possible pregnancy. If pregnancy occurs, progesterone levels in the body remain high, maintaining the womb lining. If pregnancy does not occur, progesterone levels in the body fall, resulting in a menstrual period. Continuin tricks the body processes into thinking that ovulation has already occurred, by maintaining high levels of the synthetic progesterone. This prevents the release of eggs from the ovaries.
Continuin for patients
Continuin Interactions
Ethinyl estradiol: Substrate of CYP3A4 (major), 3A5-7 (minor); Inhibits CYP1A2 (weak), 2B6 (weak), 2C19 (weak), 3A4 (weak).
Acetaminophen: May increase plasma concentration of synthetic estrogens, possibly by inhibiting conjugation. Combination hormonal contraceptives may also decrease the plasma concentration of acetaminophen.
Acitretin: Interferes with the contraceptive effect of microdosed progestin-containing "minipill" preparations. The effect on other progestational contraceptives (eg, implants, injectables) is unknown.
Aminoglutethimide: May increase CYP metabolism of progestins leading to possible decrease in contraceptive effectiveness. Use of a nonhormonal contraceptive product is recommended.
Antibiotics (ampicillin, tetracycline): Pregnancy has been reported following concomitant use, however, pharmacokinetic studies have not shown consistent effects with these antibiotics on plasma concentrations of synthetic steroids. Use of a nonhormonal contraceptive product is recommended.
Anticoagulants: Combination hormonal contraceptives may increase or decrease the effects of coumarin derivatives. Combination hormonal contraceptives may also increase risk of thromboembolic disorders.
Anticonvulsants (carbamazepine, felbamate, phenobarbital, phenytoin, topiramate): Increase the metabolism of ethinyl estradiol and/or some progestins, leading to possible decrease in contraceptive effectiveness. Use of a nonhormonal contraceptive product is recommended.
Ascorbic acid: Doses of ascorbic acid (vitamin C) 1 g/day have been reported to increase plasma concentration of synthetic estrogens by ~47%, possibly by inhibiting conjugation; clinical implications are unclear.
Atorvastatin: Atorvastatin increases the AUC for norethindrone and ethinyl estradiol.
Benzodiazepines: Combination hormonal contraceptives may decrease the clearance of some benzodiazepines (alprazolam, chlordiazepoxide, diazepam) and increase the clearance of others (lorazepam, oxazepam, temazepam).
Clofibric acid: Combination hormonal contraceptives may increase the clearance of clofibric acid.
Cyclosporine: Combination hormonal contraceptives may inhibit the metabolism of cyclosporine, leading to increased plasma concentrations; monitor cyclosporine levels.
CYP3A4 inducers: CYP3A4 inducers may decrease the levels/effects of ethinyl estradiol. Example inducers include aminoglutethimide, carbamazepine, nafcillin, nevirapine, phenobarbital, phenytoin, and rifamycins.
Griseofulvin: Griseofulvin may induce the metabolism of combination hormonal contraceptives causing menstrual changes; pregnancies have been reported. Use of barrier form of contraception is suggested while on griseofulvin therapy.
Morphine: Combination hormonal contraceptives may increase the clearance of morphine.
Non-nucleoside reverse transcriptase inhibitors (NNRTIs): Nevirapine may decrease plasma levels of combination hormonal contraceptives; use of a nonhormonal contraceptive product is recommended. No data for delavirdine; incomplete data for efavirenz.
Prednisolone: Ethinyl estradiol may inhibit the metabolism of prednisolone, leading to increased plasma concentrations.
Protease inhibitors: Amprenavir, lopinavir, nelfinavir, and ritonavir have been shown to decrease plasma levels of combination hormonal contraceptives; use of a nonhormonal contraceptive product is recommended. Indinavir has been shown to increase plasma levels of combination hormonal contraceptives. No data for saquinavir.
Rifampin: Rifampin increases the metabolism of ethinyl estradiol and some progestins (norethindrone) resulting in decreased contraceptive effectiveness and increased menstrual irregularities. Use of a nonhormonal contraceptive product is recommended.
Salicylic acid: Combination hormonal contraceptives may increase the clearance of salicylic acid.
Selegiline: Combination hormonal contraceptives may increase the serum concentration of selegiline.
Theophylline: Ethinyl estradiol may inhibit the metabolism of theophylline, leading to increased plasma concentrations.
Tricyclic antidepressants (amitriptyline, imipramine, nortriptyline): Metabolism may be inhibited by combination hormonal contraceptives, increasing plasma levels of antidepressant; use caution.
ETHANOL / NUTRITION / HERB INTERACTIONS:
Food: CNS effects of caffeine may be enhanced if combination hormonal contraceptives are used concurrently with caffeine. Grapefruit juice increases ethinyl estradiol concentrations and would be expected to increase progesterone serum levels as well; clinical implications are unclear.
Herb/Nutraceutical: St John's wort may decrease the effectiveness of combination hormonal contraceptives by inducing hepatic enzymes. Avoid dong quai and black cohosh (have estrogen activity). Avoid saw palmetto, red clover, ginseng.
Continuin Contraindications
Hypersensitivity to ethinyl estradiol, ethynodiol diacetate, or any component of the formulation; history of or current thrombophlebitis or venous thromboembolic disorders (including DVT, PE); active or recent (within 1 year) arterial thromboembolic disease (eg, stroke, MI); cerebral vascular disease, coronary artery disease, valvular heart disease with complications, severe hypertension; diabetes mellitus with vascular involvement; severe headache with focal neurological symptoms; known or suspected breast carcinoma, endometrial cancer, estrogen-dependent neoplasms, undiagnosed abnormal genital bleeding; hepatic dysfunction or tumor, cholestatic jaundice of pregnancy, jaundice with prior combination hormonal contraceptive use; major surgery with prolonged immobilization; heavy smoking (15 cigarettes/day) in patients >35 years of age; pregnancy.
Additional information about Continuin
Continuin Indication: For the prevention of pregnancy in women who elect to use this product as a method of contraception.
Mechanism Of Action: Binds to the progesterone and estrogen receptors. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Once bound to the receptor, progestins like Continuin will slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH (luteinizing hormone) surge.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Ethynodiol Diacetate
Synonyms: Ethinodiol Diacetate; Ethynodiol; Etynodiol
Drug Category: Contraceptives, Oral, Synthetic
Drug Type: Small Molecule; Approved
Other Brand Names containing Ethynodiol Diacetate: Cervicundin; Continuin; Femulen; Luteonorm; Luto-Metrodiol; Metrodiol; Metrodiol Diacetate; Metrulen; Ovulen; Ovulen 50;
Absorption: Not Available
Toxicity (Overdose): Not Available
Protein Binding: 50-85%
Biotransformation: Not Available
Half Life: Not Available
Dosage Forms of Continuin: Tablet Oral
Chemical IUPAC Name: [(3S,8R,9S,10R,13S,14S,17R)-17-acetyloxy-17-ethynyl-13-methyl-2,3,6,7,8,9,10,11,12,14,15,16-dodecahydro-1H-cyclopenta[a]phenanthren-3-yl] acetate
Chemical Formula: C24H32O4
Ethynodiol Diacetate on Wikipedia: https://en.wikipedia.org/wiki/Ethynodiol_diacetate
Organisms Affected: Humans and other mammals