2/18 Rx: Antipsychotics

Question 1

MOA of typical psychotics

Answer 1

block D2 receptor

Question 2

MOA of atypical psychotics

Answer 2

block D2, 5-HT2, a1, H1

D2: relieve positive sx
5-HT2: relieve negative sx
a1: produce ANS effects, eg. orthostatic hypOTN, tachycardia
H1: produce sedation
muscarinic: produce confusion and memory impairment, protection against extrapyramidal side effects (EPS)

Question 3

what reduces the risk of EPS?

Answer 3

lower affinity for D2 receptors (atypical 2˚ > typical 1˚)

*atypical 2˚ also have higher affinity for 5-HT2 receptors

Question 4

characteristics of typical antipsychotics

Answer 4

D2 blockers, produce EPS, inc PRL levels, equally effective but differ in potency/SEs, largely effective for positive sx (e.g. delusions, hallucinations, disorganization of thought and behavior)

Question 5

characteristics of atypical antipsychotics

Answer 5

S2 and 5HT2 anatagonism, 5HT2– reduces EPS, improve efficacy for neg sx (eg. w/drawal, flat affect, paucity of thought, avolition)

Question 6

Chlorphromazine + structure

Answer 6

allopathic side chain, low potency, inc antimuscarinic effects, inc risk of hypOTN and sedation

Question 7

thiothixene + structure

Answer 7

piperdine ring in side chain, lower incidence of EPS, inc risk of hypOTN and sedation

Question 8

fluphenazine, perphenazine + structure

Answer 8

piperazine group in side chain, potent, inc risk of EPD and weak anticholinergic effects

Question 9

haloperidol+ structure

Answer 9

butryophenones, high potency