granisetron hydrochloride: clinical use

Prescribing considerations

• Match the formulation to its licensed population and indication.
• Assess bowel function because granisetron can reduce lower-gastrointestinal motility.
• Review cardiac history, cardiotoxic chemotherapy, electrolyte abnormalities, QT-prolonging medicines and serotonergic treatment.
• Use caution in hepatic impairment despite product information not requiring routine adjustment.

Contraindications and cautions

• Hypersensitivity to granisetron or any formulation excipient.
• Consider reported cross-sensitivity after a reaction to another 5-HT3 receptor antagonist.

Monitoring

• Monitor patients with signs of subacute intestinal obstruction after administration.
• Consider ECG and clinical monitoring where arrhythmia risk is present.
• Observe for serotonin syndrome with serotonergic medicines or opioids.
• Be alert to liver-enzyme changes.

Clinical pharmacology

Granisetron is a selective 5-HT3 receptor antagonist. It is cleared mainly through hepatic oxidative metabolism followed by conjugation; CYP3A-family metabolism is implicated. Renal elimination of unchanged granisetron is limited.

Formulation and product differences

• Film-coated tablets are swallowed whole, contain lactose and are licensed for chemotherapy- and radiotherapy-associated nausea and vomiting in adults.
• The intravenous concentrate is diluted and administered by a healthcare professional. It additionally covers postoperative nausea and vomiting in adults and acute chemotherapy-associated nausea and vomiting in children aged 2 years and over.
• The intravenous concentrate contains clinically relevant sodium that varies with ampoule size; consider this where sodium intake is restricted.

Tablet

Route: Oral

Strengths: 1 mg, 2 mg

Injection

Route: Parenteral

Strengths: 1 mg/mL