Includes: indications, dosage, adverse reactions, pharmacology and more. Mean volume of distribution and terminal half-life values of lorazepam were 40% and 25% . Impairment of performance may persist for greater intervals because of. Basically, the half-life of a drug is that time required for the body to eliminate or biotransform half of the would repeat the dose at intervals less than 5 half-life's and usually less than one half-life. An important use of lorazepam. hours. Lorazepam, sold under the brand name Ativan among others, is a benzodiazepine medication. .. This explains why one lorazepam dose, despite its shorter serum half-life, has more prolonged peak effects than an equivalent diazepam . It is a Schedule IV drug under the Controlled Drugs and Substances Act in infuture.euation half-life?: ?10–20 hours.