Dolasetron

Indications

Dolasetron is used for: Nausea and vomiting associated with cancer chemotherapy

Adult Dose

Oral Nausea and vomiting associated with cancer chemotherapy Adult: 100 or 200 mg once daily w/in 1 hr before chemotherapy. Duration of treatment: 4-7 consecutive days/chemotherapy cycle. Prophylaxis of postoperative nausea and vomiting Adult: 50 mg at the induction of anaesthesia, or 100 mg w/in 2 hr before surgery. Intravenous Treatment and prophylaxis of postoperative nausea and vomiting Adult: 12.5 mg once daily as IV push over 30 seconds or via infusion over 15 min; given as soon as nausea or vomiting present (treatment) or approx 15 min before cessation of anaesthesia (prophylaxis).

Child Dose

Cancer Chemotherapy Induced Nausea & Vomiting <2 years: Safety and efficacy not established 2-16 years: 1.8 mg/kg PO 1 hr before chemotherapy; not to exceed 100 mg/dose IV may be administered PO in children aged 2-16 years: 1.8 mg/kg PO 1 hr before chemotherapy; not to exceed 100 mg/dose Note: IV administration no longer indicated for CINV because of risk for QT prolongation Postoperative Nausea & Vomiting Indicated for prevention and treatment of post-op nausea and vomiting (PONV) in children ?2 years <2 years: Safety and efficacy not established IV: 0.35 mg/kg 15 minutes before cessation of anesthesia or as soon as N/V develops; not to exceed 12.5 mg/dose IV may be administered PO in children aged 2-16 years: 1.2 mg/kg PO administered within 2 hr before surgery; not to exceed 100 mg/dose Note: Oral tablet no longer indicated for PONV

Renal Dose

Administration

IV Preparation For infusion, dilute to 50 mL in NS/D5W/D5 in 0.5 NS/D5 in LR/LR/10% mannitol injection Store vial at room temp Dilution stable for 24 hr at room temp or 48 hr refrigerated IV Administration IVP 100 mg/30 sec OR Dilute as above and infuse over up to 15 min After dilution, use within 24 hr, or 48 hr if refrigerated Do not mix with other drugs Flush infusion line before and after administration

Contra Indications

Complete heart block (w/o pacemaker), congenital QT syndrome.

Precautions

Patient w/ history of abnormal heart rhythms, structural heart disease, sick sinus syndrome, AF w/ slow ventricular response, myocardial ischemia, electrolyte abnormalities (i.e. hypokalaemia, hypomagnesemia). IV admin is not intended for prophylaxis of chemotherapy-associated nausea and vomiting. Pregnancy and lactation. Monitoring Parameters Monitor ECG, serum K and Mg concentration.

Pregnancy-Lactation

Pregnancy Category: B Lactation: not known whether distributed into breast milk, use caution

Interactions

Increased risk of QT prolongation w/ other QT prolonging agents (e.g. pimozide, ziprasideone) and drugs known to cause electrolyte imbalance (e.g. diuretics). Decreased blood levels and therapeutic effects w/ rifampicin. Increased blood levels and effects w/ atenolol and cimetidine. Increased risk of conduction abnormalities when concurrently used w/ antiarrhythmic agents (e.g. verapamil, flecainide, quinidine).

Adverse Effects

Side effects of Dolasetron : >10% Headache Diarrhea 1-10% Dizziness Drowsiness Fatigue Bradycardia HTN Hypotension Tachycardia Abdominal pain Dyspepsia Abnormal liver function Chills Fever Oliguria Urinary retention Pain Pruritus

Mechanism of Action

Dolasetron, a selective serotonin (5-HT3) receptor antagonist, has antiemetic actions similar to ondansetron. It blocks serotonin both peripherally at the GI tract (main site of action) and centrally at the chemoreceptor trigger zone.