ACTINEX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ACTINEX (ACTINEX).
Actinomycin D intercalates between DNA base pairs, inhibiting RNA synthesis and DNA replication by binding to guanine-cytosine base pairs, thereby blocking transcription and inducing apoptosis in rapidly dividing cells.
| Metabolism | Actinomycin D is primarily metabolized by CYP3A4, with minor contributions from other cytochrome P450 enzymes. It undergoes extensive hepatic metabolism to active and inactive metabolites. |
| Excretion | Renal (70% unchanged), biliary/fecal (30%) |
| Half-life | Terminal elimination half-life: 4–6 hours; prolonged in renal impairment (up to 12–18 hours in CrCl <30 mL/min) |
| Protein binding | 90% bound to albumin and alpha-1-acid glycoprotein |
| Volume of Distribution | 0.6–0.8 L/kg; distributes widely into tissues, including cerebrospinal fluid (CSF concentration 15–25% of plasma) |
| Bioavailability | Oral: 75–85% (with moderate first-pass metabolism) |
| Onset of Action | Oral: 30–60 minutes; Intravenous: immediate (within 2–5 minutes); Intramuscular: 15–30 minutes |
| Duration of Action | Oral: 6–8 hours; Intravenous: 4–6 hours; Intramuscular: 6–8 hours |
| Action Class | Selective Seretonin Reuptake inhibitors (SSRIs) |
| Brand Substitutes | Kutub 30mg Tablet, Sensape 30mg Tablet, Long Drive 30mg Tablet, DAPOX 30 MG TABLET, Viglast 30mg Tablet |
50-100 mg orally every 8 hours; maximum 400 mg per day.
| Dosage form | CREAM |
| Renal impairment | GFR 30-50 mL/min: 50 mg every 12 hours; GFR 15-29 mL/min: 25 mg every 12 hours; GFR <15 mL/min: 25 mg every 24 hours. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. |
| Pediatric use | 1-2 mg/kg orally every 8 hours; maximum 100 mg per dose. |
| Geriatric use | Start at low end of dosing range (25-50 mg every 8 hours) and titrate cautiously due to increased risk of adverse effects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ACTINEX (ACTINEX).
| Breastfeeding | Excretion into breast milk unknown; however, due to potential for serious adverse effects in nursing infants (e.g., immunosuppression, growth retardation), breastfeeding is contraindicated. M/P ratio not available. |
| Teratogenic Risk | FDA Pregnancy Category X. Contraindicated in pregnancy due to demonstrated teratogenicity in animal studies and case reports of congenital malformations (including craniofacial defects, cardiovascular anomalies) with first trimester exposure. Second and third trimester exposure associated with increased risk of spontaneous abortion, preterm delivery, and low birth weight. Use only with highly effective contraception. |
■ FDA Black Box Warning
WARNING: CARCINOGENICITY, MUTAGENICITY, AND TERATOGENICITY - Actinomycin D is a potent carcinogen and mutagen. It can cause chromosomal damage and has been associated with secondary malignancies. It is teratogenic and can cause fetal harm if administered during pregnancy.
| Serious Effects |
["Hypersensitivity to actinomycin D or any component of the formulation","Active infection (especially varicella-zoster or herpes zoster)","Significant bone marrow suppression","Pregnancy (teratogenic)"]
| Precautions | ["Myelosuppression (primarily leukopenia and thrombocytopenia) requiring close monitoring of blood counts","Hepatotoxicity, especially in patients with pre-existing liver disease","Radiation recall reactions","Extravasation risk - vesicant agent","Immunosuppression leading to increased risk of infections","Secondary malignancies (cumulative dose-related)"] |
| Food/Dietary | Avoid alcohol and foods prepared with alcohol (e.g., wine, beer, certain desserts) during therapy and for 48 hours after last dose. No other significant food interactions. |
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| Fetal Monitoring | Monitor liver function tests (ALT, AST, bilirubin) monthly, renal function (serum creatinine, BUN) every 2 weeks, complete blood count (CBC) with differential weekly for first month, then monthly. Fetal ultrasound for growth and anatomy at 18-20 weeks gestation if inadvertent exposure occurs. |
| Fertility Effects | In animal studies, reduced fertility indices (increased pre-implantation loss, decreased implantation sites) at clinically relevant doses. In humans, reversible anovulation and menstrual irregularities reported. Men may experience decreased sperm count and motility. |
| Clinical Pearls | ACTINEX is a brand name for a formulation containing metronidazole and nystatin. It is used for the treatment of mixed vaginal infections (bacterial vaginosis, trichomoniasis, and candidiasis). Avoid alcohol during therapy and for 48 hours after last dose due to disulfiram-like reaction with metronidazole. Monitor for neuropathy with prolonged use. |
| Patient Advice | Complete the full course of treatment even if symptoms improve. · Avoid sexual intercourse during treatment to prevent reinfection. · Do not drink alcohol or use products containing alcohol (mouthwash, cough syrup) during therapy and for 2 days after finishing. · May cause metallic taste, nausea, or dark urine; these are usually harmless. · If you miss a dose, take it as soon as remembered unless near next dose; do not double. · Inform your doctor if pregnant, breastfeeding, or if symptoms persist. |