51 out of 53
Ondansetron acts by (PGI June 2012)
|A||Acting on CTZ|
|C||DJ and D2 receptor antagonism|
|D||Increasing CIT motility|
|E||Blocking cholinergic receptors|
Ans. A Acting on CTZ; B. 5-HT3 antagonism (Ref KDT's 6th/646)
· Ondansetron blocks the deoplarizing action of serotonin through 5-HT3 receptors on vagal afferents in the gut as well as in NTS and CTZ.
· It does not block dopamine receptors (01 and O2) or ACh receptors.