Tropisetron

Drug Approvals

(British Approved Name, rINN)

International Nonproprietary Names (INNs) in main languages (French, Latin, Spanish):

Tropisetron Hydrochloride

(British Approved Name Modified, rINNM)

Drug Nomenclature

 

Pharmacopoeias. In Europe

European Pharmacopoeia, 6th ed. (Tropisetron Hydrochloride). A white or almost white powder. Freely soluble or soluble in water sparingly soluble in alcohol very slightly soluble in dichloromethane.

Adverse Effects and Precautions

As for Ondansetron. Fatigue, abdominal pain, and diarrhoea may also occur. Visual hallucinations, and an increase in blood pressure in patients with preexisting hypertension, have been noted at high repeated doses. ECG changes such as prolongation of QT interval have been noted with high-dose intravenous tropisetron. The drug should therefore be used with caution in patients with cardiac rhythm or conduction disturbances. Care should be taken when driving or operating machinery. No dosage reduction is considered necessary in renal or hepatic impairment despite possible reductions in clearance.

Carcinogenicity

The manufacturer (Novartis, UK) has reported an increased incidence of hepatic neoplasms in male mice given high doses of tropisetron but it is suggested that these effects are both species and sex specific.

Effects on the cardiovascular system

For a discussion of the effects of 5-HT₃ antagonists on the cardiovascular system, see under Ondansetron.

Interactions

Drugs that induce or inhibit hepatic enzymes may affect plasma concentrations of tropisetron. Licensed product information considers that any changes are usually unlikely to be clinically relevant with the recommended doses.

Tropisetron should be used with caution with anti-arrhythmics, beta blockers, or drugs likely to prolong the QT interval, including those likely to cause electrolyte disturbances.

Pharmacokinetics

Tropisetron is well absorbed after oral doses. Peak plasma concentrations are achieved within 3 hours. Absolute bioavailability depends on the dose since first-pass metabolism is saturable. It is 71% bound to plasma proteins. Tropisetron is metabolised by hydroxylation and conjugation, and metabolites are excreted mainly in the urine with a small amount in the faeces. The cytochrome P450 isoenzyme CYP2D6 is involved in tropisetron metabolism, and shows genetic polymorphism. The elimination half-life is about 8 hours in extensive metabolisers and up to 45 hours in poor metabolisers. Clearance is also reduced in patients with renal impairment.

Uses and Administration

Tropisetron is a 5-HT₃ antagonist with an antiemetic action similar to that of ondansetron. It is used in the prevention of nausea and vomiting induced by cytotoxic therapy and in the treatment and prevention of postoperative nausea and vomiting.

Tropisetron is given as the hydrochloride by slow intravenous injection or infusion, or orally. Doses are expressed in terms of tropisetron base 5.64 mg of tropisetron hydrochloride is equivalent to about 5 mg of tropisetron base.

For the prophylaxis of acute nausea and vomiting associated with cytotoxic chemotherapy a single dose of 5 mg may be given by slow intravenous injection or infusion on the day of treatment, shortly before chemotherapy. The injection is given over not less than 1 minute it may be given into a running infusion. For infusion, it is diluted into 100111L of a suitable infusion fluid (such as sodium chloride 0.9% or glucose 5%), and given over 15 minutes. Subsequent doses of 5 mg daily are given orally, in the morning at least one hour before food, for a further 5 days.

Children over 2 years of age may be given 200 micrograms/kg (maximum dose 5 mg) before chemotherapy, by intravenous injection over at least 1 minute, or by infusion (at a concentration of 50 micrograms/mL in a suitable infusion fluid). In children weighing less than 25 kg the same dose may be given intravenously once daily for up to a further 4 days as required. In those weighing more than 25 kg, a dose of 5 mg may be given orally once daily for up to a further 5 days if oral dosage is not possible the same dose may be given intravenously.

For the treatment of postoperative nausea and vomiting in adults 2 mg may be given by slow intravenous injection (over not less than 30 seconds), or by infusion (over 15 minutes), within 2 hours of the end of anaesthesia. For prophylaxis, the same dose may be given shortly before induction of anaesthesia.

Anxiety disorders

A dose-dependent anxiolytic effect was reported for tropisetron when studied in patients with generalised anxiety, but clinical evidence for the benefit of 5-HT₃ antagonists in anxiety disorders is lacking.

Fatigue

Tropisetron has been reported to be of benefit in patients with chronic fatigue, see under Uses and Administration of Ondansetron.

Pain

For reference to the use of tropisetron in various painful syndromes, see under Uses and Administration of Ondansetron.

Pruritus

Tropisetron and other 5-HT₃ antagonists have been investigated for the management of pruritus (see under Ondansetron).

Proprietary Preparations

Argentina: Navoban

Australia: Navoban

Austria: Navoban

Belgium: Novaban

Brazil: Navoban

Chile: Navoban

Czech Republic: Navoban

Denmark: Navoban

Finland: Navoban

France: Navoban

Germany: Navoban

Greece: Navoban

Hong Kong: Navoban

Hungary: Navoban

Indonesia: Navoban Setnovel

Israel: Navoban

Italy: Navoban

Japan: Navoban

Malaysia: Navoban

Mexico: Navoban

The Netherlands: Novaban

Norway: Navoban

New Zealand: Navoban

Philippines: Navoban

Poland: Navoban

Portugal: Navoban

Russia: Navoban Tropindo

South Africa: Navoban

Spain: Navoban Sanonil

Sweden: Navoban

Switzerland: Navoban

Thailand: Navoban

Turkey: Navoban

United Kingdom: Navoban

Venezuela: Navoban