PORTIA-21
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PORTIA-21 (PORTIA-21).
Oral contraceptive: inhibition of ovulation by suppressing gonadotropin release; increases viscosity of cervical mucus, reducing sperm penetration; alters endometrial receptivity.
| Metabolism | Ethinyl estradiol undergoes first-pass metabolism in liver and gut via CYP3A4; levonorgestrel metabolized via CYP3A4 and reduction/sulfation. |
| Excretion | Renal (50-60% unchanged), fecal (30-40% as metabolites), minor biliary |
| Half-life | Terminal elimination half-life: 24-30 hours; clinical context: steady-state reached after 5-7 days, allows once-daily dosing |
| Protein binding | 98-99% bound, primarily to albumin and sex hormone-binding globulin (SHBG) |
| Volume of Distribution | 2.8-4.1 L/kg, indicating extensive tissue distribution and accumulation in fat and reproductive organs |
| Bioavailability | Oral: 60-80% (first-pass metabolism reduces systemic availability); IV: 100% |
| Onset of Action | Oral: 1-2 hours for detectable serum levels; 4-6 hours for peak effect; IV: within minutes for therapeutic effect |
| Duration of Action | Oral: 24 hours (supports once-daily dosing); IV: 6-12 hours depending on dose and indication |
One tablet (norgestimate 0.180 mg/ethinyl estradiol 0.035 mg) orally once daily for 21 days, followed by 7 days of placebo.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Insufficient data for severe renal impairment (eGFR <30 mL/min/1.73 m²); use with caution. |
| Liver impairment | Contraindicated in Child-Pugh class B or C (moderate to severe hepatic impairment). For Child-Pugh class A, use with caution; no specific dose adjustment recommended. |
| Pediatric use | Not indicated for use before menarche. Post-menarche: same as adult dosing (one tablet daily for 21 days, then 7 days placebo). |
| Geriatric use | Not indicated for postmenopausal women. No specific geriatric dosing recommendations; follow standard dosing if prescribed off-label, but consider increased risk of thromboembolism and cardiovascular events. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PORTIA-21 (PORTIA-21).
| Breastfeeding | Excreted in human milk. M/P ratio not established. May reduce milk production and composition. Potential for adverse effects in the nursing infant including jaundice, breast enlargement, and hormonal disruption. Use is contraindicated during breastfeeding. |
| Teratogenic Risk | Pregnancy category X. Contraindicated in pregnancy. First trimester: Major congenital anomalies including cardiovascular, skeletal, and neural tube defects due to progestin and estrogen exposure. Second and third trimesters: Increased risk of fetal genital abnormalities, urogenital malformations, and potential long-term effects on reproductive development. Use only if pregnancy is ruled out. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combination hormonal contraceptives. Risk increases with age (especially >35) and number of cigarettes smoked. Women >35 who smoke should not use this product.
| Serious Effects |
["Thrombophlebitis or thromboembolic disorders","History of deep vein thrombosis or pulmonary embolism","Cerebrovascular or coronary artery disease","Known or suspected breast cancer","Carcinoma of endometrium or other estrogen-dependent neoplasia","Undiagnosed abnormal genital bleeding","Cholestatic jaundice of pregnancy or jaundice with prior pill use","Hepatic adenoma or carcinoma","Known or suspected pregnancy","Hypersensitivity to any component"]
| Precautions | ["Increased risk of thromboembolic disorders","Elevated blood pressure","Hepatic neoplasia or active liver disease","Gallbladder disease","Carbohydrate/lipid effects","Ocular changes (retinal thrombosis)","Headache/migraine","Menstrual irregularities"] |
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| Fetal Monitoring | Maternal: Regular pregnancy testing, liver function tests, blood pressure monitoring, lipid profile, glucose tolerance test. Fetal: Ultrasound for anatomical survey and growth assessment if inadvertent exposure occurs. Monitor for signs of fetal distress if pregnancy continues. |
| Fertility Effects | Returns fertility rapidly upon discontinuation. No known long-term impairment. May initially cause menstrual irregularities post-discontinuation but no permanent effects on ovulatory function, implantation, or subsequent fertility. |