Ondansetron toxicity

Ondansetron, other 5-HT3 antagonists 5-HT3 blockade in gut and CNS with shorter duration of binding than alosetron Extremely effective in preventing chemotherapy-induced and postoperative nausea and vomiting First-line agents in cancer chemotherapy also useful for postop emesis Usually given IV but orally active in prophylaxis. 4-9 h duration of action very low toxicity but may slow colonic transit... 

Ondansetron generally does not cause severe toxicity. Headache and constipation are the most frequent adverse effects. Light-headedness, dizziness, and transient increases in serum aminotransferase activity can occur. Extrapyramidal effects have occurred rarely, and anaphylactoid reactions have been reported. 

CANNABIS ANTI EMETICS -ONDANSETRON i levels, with risk of therapeutic failure Induction of CYP1A2-mediated metabolism by any form of smoking. Foods (e.g. broccoli, cabbage, Brussels sprouts, chargrilled meat) also induce this isoenzyme Watch for poor response to ondansetron conversely, watch for toxic effects if a previously heavy cannabis user stops smoking... 

Finn AL. Toxicity and side effects of ondansetron. Semin Oncol 1992 19(4 Suppl 10) 53-60. 

When used in combination with corticosteroids, cyclophosphamide is dosed at 1-3 mg/kg for oral therapy and 0.5-1.0 g/m of body surface area for intravenous therapy. The most common route of cyclophosphamide administration is intravenous, although there is little evidence that this is better than oral administration. Likewise, there is no evidence to suggest the optimal duration of treatment. Based on empirical experience, cyclophosphamide generally is dosed monthly for 6 months and then every 3 months for a period of either 2 years or for 1 year after the nephritis is in remission." " Of course, cyclophosphamide therapy is not without risk. Serious toxic effects include suppression of hematopoiesis, opportunistic infections, bladder complications (e.g., hemorrhagic cystitis and cancer), sterility, and teratogenesis. White blood cell counts must be monitored during cyclophosphamide therapy, and if the nadir is less than 1500/mm, the dose must be adjusted to keep the white cell count above 1500/mm. Nausea and vomiting associated with cyclophosphamide can be controlled with oral ondansetron plus dexamethasone. ... 

Cyclophosphamide produces severe nausea and is often used with a 5HT3 antagonist, ondansetron. Cyclophosphamide is metabolized to a toxic metabolite called acrolein, which can cause haemorrhagic cystitis, a rare but serious complication. This effect can be counteracted by a high intake of fiuid and by using a drug called mesna. Otherwise,... 

D. Toxicity Adverse effects of ketanserin are those of alpha blockade and Hj blockade. The toxicides of ondansetron, granisetron, and dolasetron include diarrhea and headache. Dolasetron has been associated with QRS and QT prolongation in the ECG and should not be used in patients with heart disease. Alosetron caused significant constipation in some patients. 

Drug overdose Severe toxicity occurred in a 12-month-old boy who unintentionally took 7 or 8 tablets of ondansetron 8 mg (5.6-6.4 mg/kg against a therapeutic dosage of 0.15 mg/kg), and developed obtundation and myoclonic movements of the limbs... 

Atropine or common antiemetics can be given to provide relief from nausea and vomiting, early signs of HD intoxication (Yu et al., 2003). Excellent choices for pediatric-specific antiemetics include medications such as promethazine, metoclopramide, and ondansetron (Sidell et al., 1997). Persistent vomiting and diarrhea are later signs of systemic toxicity requiring prompt fluid replacement. 

---