GIT Lec 4 Pt 5 - Anti 5-HT3 Agents

Question 1

What are some of the drugs that are found in this class?

Answer 1

Important:
1. Ondansetron (t1/2: 4-5 hours)
2. Granisetron
3. Dolasetron
4. Palanosetron
Others:
5. Bemesetron
6. Tropisetron
7. Renzapride
8. Zacopride

Question 2

What are 5-HT3 antagonists indicated for?

Answer 2

They are indicated for the treatment of cytotoxic drugs-induced emesis due to their long duration of action (which acts peripherally and on the brain)
They are efficacious against almost all grades of emetogenic therapy
They’ve been known to prevent emesis in 50-60 cisplatin-treated-patients

Question 3

What are the pharmacokinetics of 5-HT3 antagonists?

Answer 3

1. They are administered as a single dose prior to chemotherapy either orally or IV.
2. They are extensively metabolized by the liver and excreted in urine.
3. Their doses should be regulated in patients with hepatic insufficiency.

Question 4

What are the side effects of 5-HT3 agonists?

Answer 4

1. Headaches are a common side effect.
2. QT-interval elongation can occur with dolasetron.