CLORAZEPATE DIPOTASSIUM
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Binds to benzodiazepine site on gamma-aminobutyric acid type A (GABAA) receptors, enhancing GABA-mediated chloride ion influx, leading to neuronal hyperpolarization and decreased excitability.
| Metabolism | Hepatic; primarily metabolized by CYP3A4 and CYP2C19 to active metabolite N-desmethyldiazepam (nordazepam); other active metabolites include oxazepam and temazepam. |
| Excretion | Primarily renal (60-70% as oxazepam glucuronide and other metabolites), with 15-20% biliary/fecal elimination. Less than 1% excreted unchanged. |
| Half-life | 40-50 hours (clorazepate is a prodrug rapidly converted to nordiazepam); effective half-life of nordiazepam is 40-100 hours. Accumulation occurs with repeated dosing, leading to prolonged sedation in elderly or hepatic impairment. |
| Protein binding | 85-95% bound, primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.15-0.3 L/kg for clorazepate; nordiazepam Vd is 0.5-1.0 L/kg. Clinical meaning: moderate distribution, with higher Vd in obesity due to lipophilicity. |
| Bioavailability | Oral: ~100% (rapidly hydrolyzed to nordiazepam in GI tract); intravenous: not available. IM: not recommended due to erratic absorption. |
| Onset of Action | Oral: 30-60 minutes; peak effects at 1-2 hours. Rapid conversion to nordiazepam (t1/2 of conversion ~2 hours) allows for anxiolytic effect within 1 hour. |
| Duration of Action | Anxiolytic: 24-36 hours; anticonvulsant: 12-24 hours. Long duration due to active metabolite nordiazepam; steady-state achieved in 5-7 days. |
| Molecular Weight | 408.94 |
15-60 mg/day orally in divided doses 2-4 times daily; usual starting dose 15 mg at bedtime or 15 mg twice daily.
| Dosage form | CAPSULE |
| Renal impairment | GFR 10-50 mL/min: administer 50% of usual dose; GFR <10 mL/min: administer 25% of usual dose or not recommended. |
| Liver impairment | Child-Pugh Class A: consider 50% dose reduction; Child-Pugh Class B or C: contraindicated or use with extreme caution, maximum 15 mg/day. |
| Pediatric use | Not recommended for patients under 9 years; for ages 9-12: 7.5 mg twice daily initially, max 60 mg/day; for ages 12-18: same as adult dosing. |
| Geriatric use | Initial dose 7.5 mg/day orally, may increase to 15 mg/day; avoid doses >30 mg/day; monitor for excessive sedation and falls. |
| 1st trimester | Risk of congenital malformations (e.g., cleft palate) with first trimester exposure; avoid unless clearly needed. |
| 2nd trimester | May cause fetal CNS depression; use only if benefit outweighs risk. |
| 3rd trimester | Neonatal withdrawal and floppy infant syndrome; avoid during late pregnancy. |
Clinical note
CNS depressants including alcohol and opioids increase sedation risk Abrupt discontinuation can cause withdrawal symptoms.
| Placental transfer | Clorazepate and its active metabolite nordazepam cross the placenta; fetal plasma levels approximate maternal levels. |
| Breastfeeding | Clorazepate is excreted into breast milk; monitor infant for sedation, poor feeding, and weight loss. Use with caution, especially with prolonged exposure. |
■ FDA Black Box Warning
Coadministration with opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for patients without alternative treatment options.
| Common Effects | Sedation |
| Serious Effects |
Narrow-angle glaucomaSevere hepatic impairmentMyasthenia gravisHypersensitivity to benzodiazepinesPre-existing CNS depression (including acute intoxication with alcohol, opioids, or other sedatives)
| Precautions | Severe anaphylactic reactions, Central nervous system depression (concomitant CNS depressants), Physical and psychological dependence (avoid abrupt discontinuation), Acute withdrawal (including seizures) with dose reduction, Epilepsy (taper abruptly may exacerbate seizures), Paradoxical reactions (hyperactivity, aggression), Renal impairment (dose adjustment may be required), Hepatic impairment (dose reduction recommended), Use in pregnancy (risk of congenital malformations; neonatal withdrawal/SSR) |
Loading safety data…
| Lactation Rating |
| L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Increased risk of oral clefts (odds ratio ~2.2) based on animal and limited human data. Second and third trimesters: Risk of neonatal withdrawal syndrome (irritability, hypertonia, feeding difficulties) and floppy infant syndrome (hypotonia, lethargy, poor suck) following chronic exposure. Use only if benefit clearly outweighs risk. |
| Fetal Monitoring | Monitor maternal for excessive sedation, dependence, withdrawal symptoms. Fetal: Ultrasound for growth abnormalities if chronic use. Neonatal: Observe for withdrawal symptoms (hypertonia, tremors, irritability) for 48-72 hours postpartum; floppy infant syndrome may persist for weeks. |
| Fertility Effects | Animal studies show no impairment of fertility at clinically relevant doses. Human data insufficient; theoretical risk of hormonal disruption with chronic high-dose use. No well-controlled studies on human fertility. |
| Food/Dietary |
| Avoid grapefruit juice as it may increase serum levels of clorazepate. No other significant food interactions; may take with or without food. Alcohol must be avoided due to additive CNS depression. |
| Clinical Pearls | Avoid abrupt discontinuation after prolonged use; taper to reduce withdrawal risk. Use with caution in hepatic impairment or COPD. Monitor for paradoxical disinhibition reactions, especially in elderly. Peak effect occurs in 1-2 hours; long half-life allows once-daily dosing. |
| Patient Advice | Do not stop taking this medication suddenly; your dose must be slowly reduced to prevent withdrawal symptoms. · Avoid alcohol and other CNS depressants; they can increase sedation and risk of respiratory depression. · May cause drowsiness or dizziness; do not drive or operate heavy machinery until you know how this drug affects you. · Take exactly as prescribed; this medication has a risk of dependence and abuse. · Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding. · Store at room temperature away from moisture and heat. |