DASETTA 1/35
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DASETTA 1/35 (DASETTA 1/35).
Combination of an estrogen (ethinyl estradiol) and a progestin (norethindrone). Suppresses gonadotropin-releasing hormone (GnRH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion from the pituitary, thereby inhibiting ovulation. Additionally, induces changes in cervical mucus (impenetrability to sperm) and endometrium (reduced likelihood of implantation).
| Metabolism | Ethinyl estradiol is metabolized primarily by CYP3A4, with sulfation and glucuronidation also involved. Norethindrone is metabolized via reduction and conjugation (sulfate and glucuronide conjugates) and also undergoes oxidation by CYP3A4. |
| Excretion | Renal (55-60% as metabolites, 25-30% as unchanged drug and conjugates), biliary/fecal (30-35% as metabolites). |
| Half-life | Norethindrone: 5-14 hours (mean 8 hours); ethinyl estradiol: 10-20 hours (mean 14 hours). Clinical context: steady-state achieved within 5-7 days. |
| Protein binding | Norethindrone: 80-90% bound to SHBG and albumin; ethinyl estradiol: 97-98% bound to albumin. |
| Volume of Distribution | Norethindrone: 4.0 L/kg (distribution extensive into tissues); ethinyl estradiol: 4.5 L/kg (high tissue binding). |
| Bioavailability | Oral: norethindrone 50-77% (first-pass metabolism); ethinyl estradiol 38-48% (first-pass metabolism). |
| Onset of Action | Oral: inhibition of ovulation occurs within 2-3 days of consistent daily dosing; maximal contraceptive effect after 7 days. |
| Duration of Action | Oral: contraceptive effect persists as long as daily dosing continues; return to baseline fertility typically within 1-3 months after discontinuation. |
One tablet orally once daily, each containing 1 mg norethindrone acetate and 35 mcg ethinyl estradiol.
| Dosage form | TABLET |
| Renal impairment | No adjustment required for mild to moderate renal impairment. Use with caution in severe renal impairment (GFR <30 mL/min) due to potential fluid retention. |
| Liver impairment | Contraindicated in acute hepatic disease or hepatocellular carcinoma. For mild hepatic impairment (Child-Pugh A), use with caution; no specific dose adjustment established. Avoid in moderate to severe (Child-Pugh B or C) due to impaired hormone clearance. |
| Pediatric use | Not indicated for use before menarche. For postmenarchal adolescents, dosing is same as adults: one tablet orally once daily. |
| Geriatric use | Not indicated for use after menopause. No specific geriatric dosing recommendations; consider risk of thrombotic events and comorbidities. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DASETTA 1/35 (DASETTA 1/35).
| Breastfeeding | Contraindicated. Diethylstilbestrol is excreted in breast milk; M/P ratio unknown. Potential estrogenic effects in infants. Alternative contraception recommended. |
| Teratogenic Risk | Category X. First trimester: Risk of cardiovascular defects and neural tube defects; second and third trimesters: Risk of female genital tract anomalies (e.g., vaginal adenosis, clear cell adenocarcinoma) due to diethylstilbestrol component. |
| Fetal Monitoring |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular adverse effects from combination oral contraceptives (COCs). This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. For this reason, COCs should not be used by women who are over 35 years of age and smoke.
| Serious Effects |
["Thrombophlebitis or thromboembolic disorders (current or history)","Cerebrovascular or coronary artery disease (current or history)","Known or suspected breast carcinoma","Undiagnosed abnormal genital bleeding","Cholestatic jaundice of pregnancy or jaundice with prior oral contraceptive use","Hepatic adenoma or carcinoma (current or history)","Known or suspected pregnancy","Active liver disease (e.g., acute viral hepatitis, severe cirrhosis)","Hypersensitivity to any component of the product","Use of Hepatitis C drug combinations containing ombitasvir/paritaprevir/ritonavir, with or without dasabuvir"]
| Precautions | ["Thrombotic and other vascular events (e.g., venous thromboembolism, myocardial infarction, stroke)","Liver disease (e.g., hepatic adenomas, hepatocellular carcinoma)","Elevated blood pressure","Carbohydrate and lipid metabolic effects","Gallbladder disease","Dermatologic conditions (e.g., chloasma, photosensitivity)","Ocular effects (e.g., retinal thrombosis)","Depression","Cervical cancer screening","Hereditary angioedema","Interference with laboratory tests"] |
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| Monitor for signs of fetal exposure: ultrasound for structural anomalies; pregnancy test before initiation; liver function tests due to estrogen component. |
| Fertility Effects | May impair fertility by disrupting ovulation and endometrial receptivity; long-term use may cause amenorrhea or anovulation. |
| Food/Dietary | No specific food interactions are known for DASETTA 1/35. However, grapefruit juice may increase estrogen levels by inhibiting CYP3A4 metabolism; consider limiting grapefruit intake. St. John's Wort can reduce efficacy of oral contraceptives and should be avoided. |
| Clinical Pearls | DASETTA 1/35 is a monophasic combination oral contraceptive containing 1 mg norethindrone and 35 mcg ethinyl estradiol. It is used for contraception and may also regulate menstrual cycles. The pill-free interval is 7 days. Instruct patients to take one tablet daily at the same time. If a pill is missed, follow standard missed pill guidelines: if missed by <24 hours, take it immediately; if by >24 hours, take the missed pill and skip the placebo week. Breakthrough bleeding is common in the first few cycles; consider adjusting estrogen dose if persistent. Counsel about increased thromboembolic risk in smokers >35 years old. |
| Patient Advice | Take one tablet at the same time every day for 21 days, then 7 placebo pills. · Start the pack on the first Sunday after menstruation begins or on the first day of menses. · If you miss a pill, take it as soon as remembered unless >24 hours late; then take two pills the next day. · Use backup contraception (e.g., condoms) if you miss more than one pill or if vomiting/diarrhea occurs within 4 hours of taking a pill. · Report signs of blood clots: sudden leg pain, shortness of breath, chest pain, or headache. · Do not smoke while taking this medication, especially if over 35 years old. · The pill does not protect against sexually transmitted infections. |