Can ativan (lorazepam) decrease libido and cause an inability to have an orgasm?

Potentially: Ativan (lorazepam) is a sedative. Like any other benzodiazepine, alcohol, barbiturate, etc., it will have a dose-dependent depressant effect on your energy / motivation (hence libido), and in higher doses can basically prolong physiologic process to orgasm so long as to make unobtainable. Talk to your dr about this important side effect and treatment alternatives.