Dolasetron

ANZEMET

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Pronunciation: dol-A-se-tron

Dolasetron ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Dolasetron ballicule

What it is5-HT3-antagonist prodrug converted to hydrodolasetron; prevention of postoperative nausea and vomiting.

Why this oneIts active metabolite prolongs cardiac conduction enough that the IV formulation lost its chemotherapy-nausea role.

What limits it⚑ IV use for chemotherapy nausea is contraindicated because of QT prolongation and torsades; assess rhythm risk even with oral use.

Dolasetron molecular structure (skeletal formula) — Molecular structure: Dolasetron

FDA label

Read the full label on DailyMed ↗

FDA dosing	Population	Start	Target	Max
Prevention of chemotherapy-induced nausea/vomiting	Adults	100 mg PO single dose within 1 h before chemotherapy	Same (single dose)	100 mg/dose — do not exceed
Prevention of chemotherapy-induced nausea/vomiting	Peds 2-16 y	1.8 mg/kg PO single dose within 1 h before chemotherapy	Same (single dose)	100 mg/dose

Renal No adjustment needed; ECG monitoring recommended in renal impairment

Hepatic No adjustment needed

Do not exceed recommended doses; ECG monitoring recommended for elderly and renally impaired

Instructions

Give within 1 hour before chemotherapy
Peds unable to take tablets: injection solution may be mixed in apple or apple-grape juice for oral dosing (stable 2 h at room temp)

Available strengths

tab 50 mg

Cautions

Dose-dependent QT prolongation (IV dolasetron contraindicated for CINV prevention); ECG monitoring recommended in elderly and renal impairment
Post-marketing: wide-complex/ventricular tachycardia and ventricular fibrillation cardiac arrest after IV administration
Bradycardia, ECG interval changes observed in trials

Adverse reactions

Headache (18-23%)
Fatigue
Diarrhea
Bradycardia
Dizziness
Tachycardia
Dyspepsia
ECG changes

Pregnancy No fetal harm in rat/rabbit studies (8-16x human dose); no adequate human studies — use only if clearly needed

Lactation Undefined

Cost

Dolasetron (ANZEMET)

Strength		#/mo	generic $/unit	CostPlus
50 mg	tab	per unit		not offered

NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. Dolasetron is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.

NO BOXED WARNINGS

Principal riskQT prolongation; the IV form is contraindicated for chemotherapy nausea

Classes and tags

QT-prolonging medications

Clinical profile

Therapeutic safety burden2 / 4

Overdose danger1 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades2 / 4

Direct muscarinic antagonism0 / 4

Legacy pregnancy categoryB

Defining liabilityQT, PR and QRS prolongation with serious arrhythmia risk

Serotonicity

This drug is routinely called serotonergic. By Gillman’s human-effect criteria it does not raise serotonin in the synapse.

Gillman’s four human testsA measurable SERT affinity that fails all four is not clinical serotonicity.

Retarded orgasm
Efficacy in OCD and cataplexy
Clonus and hyperreflexia in single-drug overdose
Serotonin toxicity when combined with an MAOI

Background: what serotonicity is · what is and is not an SRI · what counts as a relevant MAOI.

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