Article Contents ::
Details About Generic Salt :: Ondansetron
Main Medicine Class:: Gastrointestinal System Sub Medicine Class :: Anti Emetics
7D. ANTI-EMETICS in 7. GASTROINTESTINAL SYSTEM |
ONDANSETRON |
SELECTIVE 5-HT3 RECEPTOR ANTAGONIST | ANTI-EMETIC |
PK: A: Well absorbed D: Vd: 1.7-3.7 L/kg (children); 2.2-2.5 L/kg (adults) M: Hepatic E: Urine (44-60% as metabolites, ~5% as unchanged drug), feces (~25%) |
Indications & Dose: CHEMOTHERAPY-INDUCED EMESIS RECTAL Adult Highly emetogenic chemotherapy: 16mg suppository 1-2h before treatment, Less emetogenic chemotherapy/radiotherapy: 16mg OD up to 5 days after the end of chemotherapy course | PREVENTION OF CHEMOTHERAPY-INDUCED EMESIS PO Adult Highly-emetogenic agents/single-day therapy: 24mg 30min prior to the start of therapy, Moderately-emetogenic agents: 8mg 30 min before chemotherapy, repeat 8h after initial dose, then 8mg q12h for 1-2 days after chemotherapy completed Child Moderately-emetogenic: 4-11 yr: 4mg 30min before chemotherapy, repeat 4 & 8h after initial dose, then 4mg q8h for 1-2 days after chemotherapy completed, >12 yr: Same as adult dose | IV Adult 0.15mg/kg TID beginning 30 min prior to chemotherapy or 0.45mg/kg OD or 8-10mg 1-2 times/day or 24mg or 32mg OD Child 6 months-18 yr: 0.15mg/kg/dose before 30min to chemotherapy, 4 & 8h after the first dose or 0.45mg/kg/day as single dose | PREVENTION OF POSTOPERATIVE NAUSEA & VOMITING PO Adult 16mg 1h prior to induction of anesthesia | IV Child 1 month-12 yr: <40 kg: 0.1mg/kg single dose, >40 kg: 4mg single dose | IV/IM Adult 4mg as single dose 30min before the end of anesthesia or as treatment if vomiting occurs after surgery | RADIATION INDUCED NAUSEA/VOMITING Prophylactic therapy PO Adult Total body irradiation: 8mg 1-2h before daily each fraction of radiotherapy. Single high-dose fraction radiotherapy to abdomen: 8mg 1-2h before irradiation, then 8mg q8h after first dose for 1-2 days after completion of radiotherapy. Daily fractionated radiotherapy to abdomen: 8mg 1-2h before irradiation, then 8mg 8h after first dose for each day of radiotherapy |
Contra: Hypersensitivity, concomitant use of apomorphine
Precautions: Hepatic impairment, phenylketonuria, children <12 yrs ADR: Serious: Anaphylaxis, bronchospasm, EPS, chest pain, hypotension, transient ECG changes including QT interval prolongation, Others: constipation, diarrhea, abdominal pain, dry mouth, urinary retention, rash, pain at Inj site, shivering, headache, dizziness, malaise, drowsiness, fatigue, weakness DDI: Serious Apomorphine causes hypotension, β-blockers/Anti-Arrhythmics increases in QTc interval, Amphetamine leads to subjective feelings such as light-headedness, Rifampicin modestly reduces drug levels, Tramadol reduces pain control & increases nausea/vomiting Diet: With/without food |