Benzodiazepine Comparison Chart

Benzodiazepine	Onset of Action2	Peak Onset (hrs)	Half-life parent (hrs)	Half-life metabolite (hrs)	Comparative Oral Dose
Long Acting
Diazepam1 (Valium®)	Rapid (po, IV)	1(po)	20-50	3-100	5 mg
Intermediate  Acting
Alprazolam1 (Xanax®)	Int.	0.7-1.6	6-20	-	0.5mg
Clonazepam1 (Rivotril®)	Int.	1-4	18-39	-	0.25mg
Lorazepam1 (Ativan®)	Int. (po), Rapid (sl, IV)	1-1.5 (po)	10-20	-	1mg
Short Acting
Midazolam1 (Versed®)	Most  Rapid IV	0.5-1 (IV )	1-4	-	-

¹ formulary drug
² Rapid onset = within 15 minutes, Intermediate = 15-30 minutes, Slow = 30-60 minutes

References:

1. http://clincalc.com/Benzodiazepine/?example
2. http://emedicine.medscape.com/article/2172250-overview