There are currently 16 medicines listed in US state and federal lethal injection protocols.
These are: Pentobarbital (15 states and the Federal Government); Midazolam (7 states); Sodium Thiopental (13 states); Methohexital Sodium (1 state); Diazepam (1 state); Hydromorphone (1 state); Fentanyl (2 states); Alfentanil (1 state); Ketamine (1 state); Etomidate (1 state); Pancuronium Bromide (10 states); Rocuronium Bromide (5 states); Vecuronium Bromide (6 states); Cisatracurium Besylate (2 states); Potassium Chloride (15 states); and Potassium Acetate (2 states).