1. 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 derivatives (chlorpromazine), Piperdine derivatives (thioridazine) and Piperazine derivatives (perphenazine).  Aliphatic and Piperdine derivatives are the least potent and have side effects such as sedation and weight gain while Piperazine derivatives are the more potent drugs and have side effects such as blurring of vision, clumsiness and skin rash or itchiness. 

2. WHICH RECEPTORS IN PARTICULAR ARE BLOCKED BY THE TYPICAL ANTIPSYCHOTICS DRUGS?

There is a blockade of D2 receptors and blockade of 5HT2a receptors.

3. HOW DOES THE MECHANISM OF ACTION OF THE ATYPICAL DRUGS DIFFER FROM THAT OF THE TYPICAL DRUGS?

Atypical drugs have a higher affinity to block 5-Ht2a receptors than D2 receptors while typical antipsychotics have a higher affinity to block D receptors than 5HT2a receptors.

4. WHICH OF THE RECEPTORS BLOCKED BY THE OLDER DRUGS REDUCE THE RISK OF EXTRAPYRAMIDIAL SIDE EFFECTS?

The blockade of serotonin (5HT2a) receptors and the fact that the drugs are low potent so they have a weaker bond to the dopamine receptors so this reduces the risk of EPS.

5. WHICH OF THE DRUGS HAS A HIGH INCIDENCE OF EXTRAPYRAMIDIAL SIDE EFFECTS? WHATS THE REASON FOR THIS?

Haloperidol, it has a high affinity for D2 receptors and has a high potency so that means it has a stronger bond to the dopamine receptors and thus has a high incidence of EPS than most of the other typical antipsychotics.

6. BECAUSE OF WHICH RECEPTOR BLOCKADE DO THE ALIPHATIC GROUP OF DRUGS HAVE A HIGH INCIDENCE OF AUTONOMIC SIDE EFFECTS?

 A blockade of alpha 1 receptors may lead to autonomic side effects such as urinary problems(retention), hypertension and orthostatic hypotension.