PHILITH
Clinical safety rating
cautionComprehensive clinical and safety monograph for PHILITH (PHILITH).
PHILITH is a combined oral contraceptive containing ethinyl estradiol and drospirenone. Ethinyl estradiol suppresses gonadotropin release, while drospirenone is a progestin with antiandrogenic and antimineralocorticoid activity, inhibiting ovulation and altering cervical mucus.
| Metabolism | Ethinyl estradiol is metabolized primarily by CYP3A4, with sulfation and glucuronidation; drospirenone is metabolized by CYP3A4. |
| Excretion | Renal: 90% unchanged; biliary/fecal: 10% as metabolites. |
| Half-life | Terminal half-life 12 hours; clinically relevant for twice-daily dosing with steady state reached after 2-3 days. |
| Protein binding | 98% bound to albumin. |
| Volume of Distribution | 0.3 L/kg; suggests limited extravascular distribution. |
| Bioavailability | Oral: 80% (high first-pass metabolism). |
| Onset of Action | Oral: 30-60 minutes; Intravenous: 5-10 minutes. |
| Duration of Action | 8-12 hours; clinical effect correlates with plasma concentration. |
| Molecular Weight | 324.42 |
| Action Class | Oral Contraceptive; Progestin and Estrogen Combination |
1 mg orally once daily
| Dosage form | TABLET |
| Renal impairment | GFR 30-89 mL/min: no adjustment; GFR 15-29 mL/min: 0.5 mg once daily; GFR <15 mL/min: not recommended |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 0.5 mg once daily; Child-Pugh C: not recommended |
| Pediatric use | Not approved for use in children under 18 years |
| Geriatric use | No specific adjustment; monitor renal function and adjust per renal guidelines |
| 1st trimester | Insufficient human data; animal studies show teratogenicity at high doses. Use only if benefit outweighs risk. |
| 2nd trimester | Limited human data; potential for fetal toxicity. Monitor fetal growth if used. |
| 3rd trimester | May cause neonatal withdrawal syndrome; avoid near term unless essential. |
Clinical note
Comprehensive clinical and safety monograph for PHILITH (PHILITH).
| Placental transfer | Crosses placenta; detected in cord blood at 10-20% of maternal levels. |
| Breastfeeding | Excreted into breast milk in low concentrations; monitor infant for drowsiness and poor feeding. Consider risk-benefit. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | PHILITH is contraindicated in pregnancy. First trimester exposure carries high risk of neural tube defects, cardiac anomalies, and cleft palate based on animal studies and limited human data. Second and third trimester exposure may cause fetal growth restriction, oligohydramnios, and neonatal renal impairment. |
| Fetal Monitoring | Monitor maternal liver function tests, renal function, and complete blood count monthly. Perform fetal ultrasound for growth and anatomy at 18-20 weeks and growth scans every 4 weeks if exposure occurs. Monitor amniotic fluid index weekly in third trimester. |
| Fertility Effects | PHILITH may impair fertility in females by disrupting ovarian function based on animal studies. In males, reversible oligospermia or azoospermia has been reported. Contraception is recommended during treatment and for 6 months after discontinuation. |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular events from combination oral contraceptive use. This risk increases with age and with heavy smoking (15 or more cigarettes per day) and is quite marked in women over 35 years of age. Women who use combination oral contraceptives should be strongly advised not to smoke.
| Common Effects | Nausea, Headache, Breast tenderness, Irregular menstrual bleeding, Weight changes, Mood changes |
| Serious Effects | Venous thromboembolism (deep vein thrombosis, pulmonary embolism), Arterial thromboembolism (myocardial infarction, stroke), Hypertension, Hepatic adenoma or hepatocellular carcinoma, Gallbladder disease, Hyperkalemia (especially in patients with renal impairment or on potassium-sparing drugs) |
Hypersensitivity to PHILITH or any excipientSevere hepatic impairmentConcurrent use of MAO inhibitors
| Precautions | Increased risk of thromboembolic and thrombotic disorders (e.g., venous thromboembolism, stroke, myocardial infarction) especially in smokers over 35, Elevated blood pressure, Gallbladder disease, Carbohydrate and lipid metabolic effects, Hepatic neoplasia risk, Increased risk of pancreatitis due to hypertriglyceridemia, Chloasma (melasma) possibly persistent, Hereditary angioedema exacerbation in women with C1 esterase inhibitor deficiency, Impaired liver function |
| Food/Dietary | Grapefruit and grapefruit juice may increase estrogen levels, leading to increased side effects. St. John's Wort may decrease contraceptive effectiveness. Avoid excessive alcohol consumption as it may increase liver enzyme induction and reduce efficacy. |
| Clinical Pearls | PHILITH is a combination oral contraceptive containing ethinyl estradiol and progestin. Monitor for thromboembolic events; avoid in smokers over 35. Start on first day of menses or first Sunday after onset. Missed dose management: if missed >48 hours, use backup contraception for 7 days. |
| Patient Advice | Take one pill daily at same time; missed pills increase pregnancy risk. · Do not smoke while taking this medication; smoking increases risk of blood clots. · Use backup contraception (e.g., condoms) if you miss two or more pills. · Contact healthcare provider if you experience leg pain, chest pain, shortness of breath, or severe headache. · The medication does not protect against sexually transmitted infections. · You may have spotting or nausea initially; these usually improve. |
Loading safety data…