Delorazepam Stats & Data
O=C1CN=C(c2ccccc2Cl)c2cc(Cl)ccc2N1CHIFCDOIPRCHCF-UHFFFAOYSA-NPharmacology
DrugBankDescription
Delorazepam is a benzodiazepine which, like other drugs in its class, possesses anxiolytic, skeletal muscle relaxant, hypnotic and anticonvulsant properties. It may have adverse effects such as drowsiness, and cognitive impairments such as short term memory impairment. Delorazepam is an active metabolite of the benzodiazepine known as cloxazolam. It is a long acting benzodiazepine which makes it superior in this sense to lorazepam which is short acting. Lorazepam is also a major active metabolite of delorazepam. In addition to be long acting, delorazepam is relatively potent, with 1 mg of delorazepam being the equivalent of 10 mg diazepam. It has been approved for marketing in Italy.
Metabolism
Delorazepam is metabolized at a relatively slow pace by the liver. The major metabolite (15-34% of the parent drug) is lorazepam. Older patients metabolize delorazepam slower than younger patients.
Absorption
77-87% oral bioavailability, with a relatively slow absorption rate. Reaches peak plasma levels within 1-2 hours of administration. Food may slow absorption, however other pharmacokinetic variables remain unchanged. After multiple doses delorazepam accumulates, although accumulation is slower in younger patients.
Toxicity
Older patients metabolize delorazepam slower than younger patients and thus suffer from more adverse effects.
Indication
Mainly used as an anti-anxiety agent. Studies have found delorazepam to be more effective in the first 4 weeks of use than antidepressants; however, after 4 weeks, antidepressants showed superior anti-anxiety effects. Anti-anxiety effects also appear to be weaker in elderly patients. Effectiveness has also been observed in the treatment of alcohol withdrawal. Delorazapam was reported to be a manageable drug in that it did not exhibit severe side effects and did not require further therapies to control symptoms of withdrawal.
Half-life
Very long elimination half life of 80-115 hours, varying with age. Elimination is slower as age increases. Liver disease also impacts elimination half life, with impairment resulting in half lives up to 395 hours.
Elimination
Renally eliminated.
Volume of Distribution
140 L/kg apparent volume of distribution in 11 patients with normal renal function; 47 L/kg in 11 patients with renal failure and on regular hemodialysis. In another study, apparent volume of distribution was 65 L/kg in 8 patients with liver disease and 118.4 L/kg in 12 healthy controls.
Clearance
Still detectable 72 hours after dosing in healthy patients. Patients with liver disease experienced a reduction in clearance from 0.13 to 0.25 ng/mLh.
Receptor Profile
Receptor Actions
History & Culture
Delorazepam is an uncommon benzodiazepine that has been marketed primarily in Italy, where it is available under the trade name EN. The compound is notable for its relationship to other benzodiazepines in this class, serving as an active metabolite of both diclazepam and cloxazolam. As a derivative of desmethyldiazepam, it shares structural similarities with several other members of the benzodiazepine family. Despite its limited international availability compared to more widely prescribed benzodiazepines, delorazepam has found clinical application in Italy for anxiety-related conditions, including its use as a premedication for patients experiencing dental phobia.
Effect Profile
CuratedStrong anxiolysis, cognitive impairment, and euphoria with mild sedation
Tolerance & Pharmacokinetics
drugs.wikiTolerance Decay
References
Data Sources
Cited References
- Albani et al. Pharmacokinetics of delorazepam after single and repeated oral doses. Eur J Clin Pharmacol 1983;25(1):101-6
- Delorazepam - DrugBank Online
- Delorazepam - PubChem (NIST)
- Delorazepam - Tripsitter Harm Reduction Guide
- Dextro.45. '5 Days Trip, No Benzos - interesting outcome' (experience report) Bluelight.org, 2023-06-18
- Italian SPC - EN (delorazepam) 0.5 mg tablets, Chiesi Farmaceutici
- PubChem: Compound Summary for CID 4179 (Delorazepam)
- PsychonautWiki: Benzodiazepines