Phenobarbitone is the most commonly used barbiturate for premedication aIthough, in general, these agents are rarely used since the introduction of the benzodiazepines. Barbituric acid.
It is thought that this inspired the naming of the compound ‘barbituric acid’. Phenobarbitone is available in both oral and injectable form. Pharmacologically it is a depressant, depressing the function of many body systems often at a micromolecular level. Its most profound therapeutic actions are central nervous system (CNS) sedation and the control of epilepsy. Its action on the CNS varies with dosage: increasing the dosage increases the sedation until eventually the vital centres controlling the respiratory muscles and heart are depressed.
In small doses it is a sedative and in larger doses an hypnotic, (i.e. it will produce sleep). Phenobarbitone served for many years as an ideal agent for premedication. Its side-effects include addiction, tolerance (i.e. more is needed each time to produce the same effect) Toilet Training with Autism and enzyme induction.