• What factors may affect the absorption and distribution of sedative-hypnotic drugs? What is the clinical significance thereof?

There are many factors that can affect the absorption and distribution of drugs like the more lipid soluble a drug is the faster the rate of adsorption will be and faster redistribution to the CNS. Other factors like drugs that inhibit CYT P450 enzymes has an effect on the elimination half-life of highly lipophilic BD which has a rapid onset of action so you should be careful to administer these drugs with impaired CYT P450 enzymes.

• What is meant by redistribution and what is the significance thereof?

Redistribution occurs when highly lipophilic drugs is redistributed from the cns to fatty tissues and muscles so it will increase its elimination half-life.

• How are the BDs metabolized? Name the various steps in the process.

BD are metabolized by

Dealkylation then by oxidation followed by conjugation

• Which BDs are converted to active metabolites? What is the significance thereof?

It is significant as it increases the drugs duration of action examples of these drugs are diazepam, chlorazepate, prazepam chlordiazepoxide and ketazolam

• Which BDs are not dependent on the cytochrome P450 oxidative enzymes for metabolism?

What are the advantages thereof?

(BOLT)

Bromazepam, oxazepam, Lorazepam and Temazapam.

It is advantageous as it can be used in patients who have impaired CYT P450 enzyme function.

• What is enzyme induction? Which of the sedative hypnotic drugs are known for this? What is the clinical significance of enzyme induction?

Enzyme induction is the increased rate of hepatic metabolism leading to increased metabolism of the drug. Drugs in this category are barbiturates like phenobarbitone