• Name an example of each of the three phenothiazine sub-families and state how they differ from one another in terms of potency and side effects.

Aliphatic side-chain:

Chlorpromazine.

Piperidine side-chain:

Periciazine.

Piperazine side-chain:

Fluphenazine.

The Aliphatic and Piperidine compounds has a low potency, thus can little EPS effects be expected. The side effects associated with these compounds are severe sedation, strong anti-cholinergic effects, strong alphalytic effects (e.g. postural hypotension) and these medications can also cause cardiotoxicity.

The Piperazine compounds has a very high potency, thus can more EPS effects be expected with the use of these compounds. They do, however have weaker anti-chlinergic effects, weaker alphalytic effects, less sedation and also less CVS side effects.

• Which receptors in particular are blocked by the typical antipsychotic drugs?

Serotonin 2A receptors

• How does the mechanism of action of the atypical drugs differ from that of the typical drugs?

The atypical drugs has a stronger anatgonism of Serotonin 2A receptors than  for the Dopamine 2 receptors. Where the typical drugs only has an affinity for the Mesolimbic D2 receptors.

• Which of the receptors blocked by the older drugs reduce the risk of extrapyramidal side effects?

Dopamine 3 receptors

• Which of the older drugs have a high incidence of extrapyramidal side effects? What is the reason for this?

Butyrophenone derivatives (Haloperidol and Droperidol), these medications are very potent Dopamine 2 blockers.

• Because of which receptor(s) blockade do the aliphatic group of drugs have a high incidence of autonomic side effects?

Alpha-receptors.