voxelotor: clinical use

Prescribing considerations

• Do not initiate voxelotor: all UK batches were recalled and the product was withdrawn in September 2024.
• Identify patients with residual supplies, arrange discontinuation and return of stock, and discuss appropriate alternatives.
• Continue appropriate follow-up after discontinuation because adverse events or clinical deterioration may occur.
• Evidence was limited in people with sickle-cell genotypes other than HbSS or HbS/β0-thalassaemia and in adults older than 65 years.

Contraindications and cautions

• Hypersensitivity to voxelotor or any product excipient.
• Do not re-challenge after voxelotor-associated hypersensitivity or DRESS.
• Safety was not established in sickle-cell disease with end-stage renal disease requiring dialysis.
• Severe hepatic impairment increases exposure and requires specialist consideration; however, the product is withdrawn.

Monitoring

• Assess promptly for painful crises, other clinical deterioration and adverse events following discontinuation.
• Review rash or systemic hypersensitivity symptoms urgently and permanently avoid re-exposure after DRESS.
• Voxelotor can interfere with HPLC measurement of haemoglobin subtypes; document recent exposure when requesting or interpreting testing.

Clinical pharmacology

Voxelotor partitions extensively into red blood cells and binds haemoglobin S, increasing oxygen affinity and inhibiting polymerisation, sickling and loss of red-cell deformability. It is metabolised mainly through CYP3A4, with a terminal elimination half-life of about 39 hours.

Formulation and product differences

• The selected UK product was a film-coated tablet intended to be swallowed whole.
• No alternative selected UK formulation is represented on this page.
• All batches of the tablet product were recalled from the UK market.

Tablet

Route: Oral

Strengths: 500 mg