GEN-XENE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GEN-XENE (GEN-XENE).
Benzodiazepine that enhances GABA-A receptor activity by binding to the benzodiazepine site, increasing chloride ion conductance and neuronal inhibition.
| Metabolism | Hepatic via CYP3A4; active metabolite N-desmethyldiazepam; also undergoes glucuronidation. |
| Excretion | Renal: ~80% as glucuronide and oxidized metabolites; fecal: ~20% via biliary excretion. |
| Half-life | 30–100 hours (mean ~50 h); prolonged in elderly and hepatic impairment; steady-state achieved in 7–10 days. |
| Protein binding | 95–99% bound, primarily to albumin. |
| Volume of Distribution | 0.5–2.0 L/kg; indicates extensive tissue distribution. |
| Bioavailability | Oral: 85–100%; rectal: 90%. |
| Onset of Action | Oral: 30–60 minutes; rectal: 15–30 minutes; IV: 2–5 minutes. |
| Duration of Action | 6–12 hours (single dose), up to 24 hours with accumulation; prolonged with high doses or chronic use. |
| Molecular Weight | 408.79 |
Initial: 10 mg PO TID; maintenance: 20-40 mg/day PO in divided doses; max: 120 mg/day.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-60 mL/min: reduce dose by 50%; CrCl <30 mL/min: use not recommended. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. |
| Pediatric use | Not recommended for use in children under 6 years; for children ≥6 years: initial 5 mg PO BID, titrate as needed up to 60 mg/day. |
| Geriatric use | Initial: 5 mg PO BID; increase slowly; max: 60 mg/day; increased sensitivity to CNS effects. |
| 1st trimester | Associated with increased risk of congenital malformations, particularly cleft lip/palate, when used during first trimester. Avoid if possible. |
| 2nd trimester | May be associated with preterm delivery and low birth weight; use only if clearly needed. |
| 3rd trimester | Use in third trimester may cause neonatal withdrawal symptoms (floppy infant syndrome, respiratory depression, sedation). Avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for GEN-XENE (GEN-XENE).
| Placental transfer | Clorazepate crosses the placenta readily; fetal plasma concentrations approximate maternal levels. |
| Breastfeeding | Gen-Xene (clorazepate) is excreted into breast milk in concentrations that can cause sedation and feeding difficulties in the infant. Use during breastfeeding is generally not recommended; alternative agents are preferred. |
■ FDA Black Box Warning
Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for patients for whom alternative treatment options are inadequate.
| Serious Effects |
Hypersensitivity to clorazepate or any benzodiazepineAcute narrow-angle glaucomaSevere hepatic impairmentMyasthenia gravisConcurrent use with ketoconazole or itraconazolePregnancy (first trimester) – avoid; teratogenic risk
| Precautions | Risk of dependence and withdrawal reactions after prolonged use, CNS depressant effects may impair mental alertness, Use with caution in elderly and debilitated patients due to increased sensitivity and fall risk, May cause anterograde amnesia, Should not be abruptly discontinued after long-term use |
| Food/Dietary | No significant food interactions are documented. Take with or without food. Grapefruit juice does not affect metabolism (clorazepate is not CYP3A4 dependent). |
Loading safety data…
| Lactation Rating | L4 (Possibly Hazardous) |
| Teratogenic Risk | First trimester: Increased risk of congenital malformations (e.g., oral clefts) with exposure. Second and third trimesters: Risk of CNS depression, hypotonia, respiratory depression (floppy infant syndrome), and withdrawal symptoms in neonates. Late third trimester or delivery: Potential for neonatal withdrawal syndrome. |
| Fetal Monitoring | Maternal: Liver function tests, CBC, renal function. Fetal/neonatal: Regular ultrasonography for growth and development; neonatal assessment for respiratory depression, hypotonia, and withdrawal signs after delivery. |
| Fertility Effects | May cause menstrual irregularities and anovulation at high doses, potentially affecting fertility. Reversible upon dose reduction or discontinuation. |
| Clinical Pearls | Gen-Xene (clorazepate dipotassium) is a benzodiazepine pro-drug that is rapidly decarboxylated to nordiazepam in the stomach. This leads to a slow onset but long duration, making it useful for anxiety with once-daily dosing. Due to active metabolites (nordiazepam, oxazepam), accumulation can occur in elderly or hepatic impairment. Avoid in acute narrow-angle glaucoma. Taper gradually to prevent withdrawal. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency. · Avoid alcohol and other CNS depressants while taking this medication. · Drowsiness or dizziness may occur; avoid driving until you know how you react. · Do not stop abruptly; withdrawal symptoms (anxiety, insomnia, seizures) can occur. · Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding. |