1. Pka value: With barbiturates, they are weak acids and have a pka-value of 7.2 and they are eliminated faster due to alkalinisation.

Lipophilicity: Drugs with a high lipophilicity enter the CNS rapidly and this gives them the ability to be used as induction agents in anaesthesia.

2. Redistribution means that something is distributed to another area from the area it was initially distributed to. For example, thiopental’s CNS effects are terminated through rapid distribution to other high perfused areas such as the skeletal muscles, the heart and the kidney.
3. First step is dealkylation, then it is followed by oxidation (phase 1 reaction) through the cytochrome P450 enzymes. The metabolites are subsequently conjugated (phase 2 reactions) to form glucuronides that are excreted in the urine.
4. Chlordiazepoxide, Diazepam, Prazepam, clorazepate and ketazolam. Their active metabolites contribute to the extended duration of action as they are converted into pro-drugs in which they can only show their pharmacological effects when they are in their active form.
5. Oxazepam, lorazepam, temazepam and lormetazepam. These drugs are given in their active form.

 6.  Stimulation of drug-metabolizing capacity; usually manifested in the liver by increased synthesis of smooth endoplasmic reticulum (which contains high concentrations of phase 1 enzymes). These drugs will have marked sedative, hypnotic and anxiolytic effects after the phase 1 reaction