Used to be the sedative-hypnotic drugs of choice, but are not any longer because adverse effects and risk of addiction are greater with barbiturates than new drugs.
Action: CNS depressants that inhibit neuronal impulse conduction in the ascending RAS, depress the cerebral cortex, alter cerebellar function, and depress motor output.
Indication: the relief of symptoms and signs of anxiety and for sedation, insomnia, pre anesthesia, and the treatment of seizures.
allergy, previous addiction to sedative-hypnotic drugs, porphyria, hepatic impairment or nephritis, respiratory distress, pregnancy, use with caution in patients with acute or chronic pain (can cause paradoxical excitement, masking other symptoms)
More severe than with newer sedative-hypnotics, also the development of physical and psychological dependence is more likely.
CNS effects- drowsiness, ataxia, vertigo, "hangover" feeling, thinking abnormalities, paradoxical excitement, anxiety, hallucinations.
GI effects- nausea, vomiting, constipation, diarrhea, epigastric pain.
CV effects- bradycardia, hypotension (especially with IV administration), syncope.
Hypoventilation, respiratory depression
Hypersensitivity reactions- rash, serum sickness, Stevens-Johnson syndrome