Is phenobarbital similar to xanax or valuim?

Chemically they are different. One is a benzodiazepine (Xanax) and phenobarbital is a barbiturate but they both produce relaxation and drowsiness so in a way their actions are the same but very chemically different drugs. Phenobarbital is most often used to control seizures but as a barbiturate it can produce profound relaxation of skeletal muscles and drowsiness. Most folks who take it for seizures develop tolerance for the effects of drowsiness fairly quickly. Valium is a benzodiazepine and is also used often for seizures, sometimes in conjunction with phenobarbital. Valium is one of the best muscle relaxants around that truly acts on the muscles, not just offering muscle relaxation as a result of sedation as some others in the muscle relaxant category do. Xanax is used primarily for anxiety. All three drugs can be very habit forming.