Estazolam

Absorption

Tablets have been found to be equivalent in absorption to an orally administered solution of estazolam. In healthy subjects who received up to three times the recommended dose, peak estazolam plasma concentrations occurred within two hours after dosing (range 0.5 to 6.0 hours) and were proportional to the administered dose, suggesting linear pharmacokinetics over the dosage range tested.

Toxicity

Symptoms of overdose include confusion, depressed breathing, drowsiness and eventually coma, lack of coordination, and slurred speech.

Originator

Eurodin,Takeda,Japan,1975

The Uses of Estazolam

A benzodiazepine derivative possessing anxiolytic, anticonvulsant, and muscle relaxant properties. It is commonly prescribed to treat short-term insomnia. Controlled Substance.

Background

A benzodiazepine with anticonvulsant, hypnotic, and muscle relaxant properties. It has been shown in some cases to be more potent than diazepam or nitrazepam.

Indications

For the short-term management of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings.

Definition

ChEBI: A triazolo[4,3-a][1,4]benzodiazepine having a phenyl group at position 6 and a chloro substituent at position 8. A short-acting benzodiazepine with general properties similar to diazepam, it is given by mouth as a hypnotic in the short-term ma agement of insomnia.

Manufacturing Process

A mixture of 5.74 grams (0.020 mol) of 7-chloro-1,3-dihydro-5-phenyl-2H- 1,4-benzodiazepine-2-thione, 3.6 grams (0.060 mol) of formic acid hydrazide and 200 ml of 1-butanol was refluxed for 3.75 hours with a slow stream of nitrogen bubbling through the mixture. The mixture was concentrated, the residue was suspended in water and the suspension was filtered. The filter cake consisted principally of unchanged starting material. The filtrate was concentrated, ethyl acetate and Skellysolve B hexanes being added during the concentration, giving crude product (2.54 grams), MP 220.5° to 225°C. Recrystallization of this material from ethyl acetate-Skellysolve B hexanes gave 8-chloro-6-phenyl-4H-s-triazolo[4,3-a] [1,4]benzodiazepine, MP 228° to 229°C.

brand name

Prosom (Abbott).

Therapeutic Function

Hypnotic, Sedative

Pharmacokinetics

Estazolam, a triazolobenzodiazepine derivative, is an oral hypnotic agent with anticonvulsant, hypnotic, and muscle relaxant properties. It has been shown in some cases to be more potent than diazepam or nitrazepam.

Metabolism

Extensively metabolized in the liver. In vitro studies with human liver microsomes indicate that the biotransformation of estazolam to the major circulating metabolite 4-hydroxy-estazolam is mediated by cytochrome P450 3A (CYP3A).