Of note, normal therapeutic lorazepam injectable doses contain very small amounts of propylene glycol, polyethylene glycol, and benzyl alcohol. Aug 17, - Lorazepam dosage needs to be reduced by approximately 50% .. (20 mg/kg) by several routes of administration was evaluated in normal. Mar 9, - Detailed Lorazepam dosage information for adults, the elderly and children. Includes dosages for Anxiety, Insomnia, Status Epilepticus and.