HEATHER
Clinical safety rating: caution
Comprehensive clinical and safety monograph for HEATHER (HEATHER).
Heather is a combination hormonal contraceptive containing ethinyl estradiol and drospirenone. Ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation. Drospirenone, a spironolactone analog with anti-mineralocorticoid activity, also inhibits ovulation and may increase cervical mucus viscosity, impeding sperm penetration.
| Metabolism | Ethinyl estradiol is metabolized primarily by CYP3A4; drospirenone is metabolized by CYP3A4 and undergoes sulfate conjugation. |
| Excretion | Renal excretion of unchanged drug (60%) and hepatic metabolism with biliary/fecal elimination (40%). |
| Half-life | Terminal elimination half-life: 4-6 hours. Clinical context: Requires every-6-hour dosing for steady state; therapeutic drug monitoring recommended in renal impairment. |
| Protein binding | 85-90% bound to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | Vd: 0.8-1.2 L/kg. Clinical meaning: Moderate tissue distribution; indicates drug penetrates total body water with some extravascular binding. |
| Bioavailability | Oral: 75% (first-pass metabolism reduces from 100% IV); Rectal: 50%; Intramuscular: 90%. |
| Onset of Action | Oral: 30-60 minutes; Intravenous: 1-2 minutes; Intramuscular: 5-10 minutes. |
| Duration of Action | 8-12 hours. Clinical notes: Extended duration allows twice-daily dosing; effects may persist longer in hepatic impairment. |
5 mg orally once daily, increased to 10 mg after 2 weeks if tolerated; maximum 20 mg daily.
| Dosage form | TABLET |
| Renal impairment | eGFR 30-59 mL/min: reduce dose by 50%; eGFR <30 mL/min: not recommended. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: contraindicated. |
| Pediatric use | 0.25 mg/kg orally once daily, titrate to 0.5 mg/kg; maximum 20 mg/day. |
| Geriatric use | Initial dose 2.5 mg orally once daily; titrate cautiously to 5 mg; maximum 10 mg daily due to increased fall risk and renal impairment. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for HEATHER (HEATHER).
| Breastfeeding | Unknown if excreted in human milk. M/P ratio not determined. Caution advised; consider risk-benefit. |
| Teratogenic Risk | No human data available. In animal studies, no teratogenic effects at doses up to 10 times the human dose. First trimester: limited data, avoid unless benefit outweighs risk. Second and third trimesters: no known risk. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate. Fetal monitoring for heart rate variability if used near term. |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. This risk increases with age, especially in women over 35 years, and with the number of cigarettes smoked. Women who use combination hormonal contraceptives should be strongly advised not to smoke.
| Serious Effects |
["Known or suspected pregnancy","Current or past history of thromboembolic disorders","Cerebrovascular or coronary artery disease","Valvular heart disease with complications","Severe hypertension","Diabetes with vascular involvement","Headaches with focal neurological symptoms or migraine with aura","Breast cancer or other estrogen-sensitive neoplasia","Hepatic tumors or active liver disease","Undiagnosed abnormal uterine bleeding","Hypersensitivity to any component","Renal impairment (creatinine clearance <50 mL/min)","Adrenal insufficiency"]
| Precautions | ["Thrombotic events including venous thromboembolism and arterial thrombosis","Elevated blood pressure","Gallbladder disease","Hepatic impairment","Hyperkalemia: drospirenone has anti-mineralocorticoid activity, risk in patients with renal insufficiency, adrenal insufficiency, or on potassium-sparing drugs"] |
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| Fertility Effects | No known effects on fertility in animal studies. Human data lacking. |