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. 4
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. [Wikipedia] It has been approved for marketing in Italy.
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|Weight||Average: 305.159 |
|Description||This compound belongs to the class of organic compounds known as 1,4-benzodiazepines. These are organic compounds containing a benzene ring fused to a 1,4-azepine.|
|Super Class||Organoheterocyclic compounds|
|Molecular Framework||Aromatic heteropolycyclic compounds|
|External Descriptors||Not Available|
|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. [Wikipedia] 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. |
|Mechanism of action||Not Available|
|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, however accumulation is slower in younger patients.|
|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. 5
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. 2
|Protein binding||>90% protein bound. |
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. 
|Route of elimination||Renally eliminated.|
|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. |
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. 2
|Toxicity||Older patients metabolize delorazepam slower than younger patients and thus suffer from more adverse effects. |
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1. Bareggi, S. R., et al. “Age-related multiple-dose pharmacokinetics and anxiolytic effects of delorazepam (chlordesmethyldiazepam).” International journal of clinical pharmacology research 6.4 (1986): 309.
2. Bareggi, S. R., et al. “Effects of liver disease on the pharmacokinetics of intravenous and oral chlordesmethyldiazepam.” European journal of clinical pharmacology 48.3-4 (1995): 265-268.
3. Cazzato, G., et al. “[Prevention and therapy of delirium tremens with tiapride and chlordesmethyldiazepam].” Rivista di neurologia 52.6 (1981): 331-342.
4. Scarone, S., L. F. Strambi, and C. L. Cazzullo. “Effects of two dosages of chlordesmethyldiazepam on mnestic-information processes in normal subjects.” Clinical therapeutics 4.3 (1981): 184.
5. Sennesael, J., et al. “Pharmacokinetics of intravenous and oral chlordesmethyldiazepam in patients on regular haemodialysis.” European journal of clinical pharmacology 41.1 (1991): 65-68.
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