Question

3. A 67-year-old woman, receiving chemotherapy for metastatic ovarian cancer, develops nausea and vomiting. IV ondansetron is ordered prior to her next dose of chemotherapy. What is the mechanism of action of ondansetron, and what are the common side effects associated with this drug

4. A 48-year-old man presents for evaluation of heartburn. He reports a burning feeling in his chest after eating, worse after eating spicy foods, and sometimes is awakened at night with symptoms. He has tried OTC antacids and H-2 blockers with partial relief. An upper GI X-ray series reveals GERD. Along with appropriate diet and lifestyle modifications recommendations, he is prescribed omeprazole. What is the mechanism of action of omeprazole? How long before he achieves maximal inhibition of acid secretion?

Answer 1

3) ondensetron mechanism of action- it is a serotonin 5-Ht3 antagonist . It does not have any effect on dopamine and nuscarinic receptors .
side effects of ondensetron - diarrhoea , constipation, headache, itchiness, sleepiness . Serious side effects include - QT prolongation , and severe allergic reaction.

4) omperazole is a proton pump inhibitor . It inhibits the parietal cell H+ /k+ ATP pump , the final step of acid production. it suppressed gastric nasal and stimulated acid secretion.
The inhibitory effects of omeprazole occur rapidly within 1 hr of administration, with the maximum effect occurring within 2 hrs . The inhibitory effects of omeprazole lasts for approximately 72 hrs after administration of drug , followed by return to baseline activity within 3 - 5 days .