Can taking the drug rohypnol be fatal?

Anything can be: Taking an overdose of any drug — or even huge amounts of water — can be fatal. There are reports of fatal overdoses of Rohypnol due to respiratory depression. However, more common hazards result from sedation: auto accidents, falls, criminal and sexual assaults, etc. This medication has very limited legitimate use in controlled settings, and is dangerous if used recreationally.

Rohypnol: With compromised respiratory function or if used recreationally, yes.