COSUDEX

What it is

COSUDEX is a film-coated tablet containing 50 mg bicalutamide. Bicalutamide is a non-steroidal anti-androgen that binds to androgen receptors without activating gene expression, and thus inhibits the androgen stimulus. This inhibition impairs the growth and encourages apoptosis in androgen-dependent tumour cells and regression of prostatic tumours.

Approved indications

— Treatment of advanced prostate cancer in combination with LHRH agonist therapy.

Dosing overview

The recommended dose for adult males including the elderly is one tablet (50 mg) once a day. Treatment with bicalutamide 50 mg should be started at the same time as treatment with a LHRH agonist. No dosage adjustment is necessary for patients with renal impairment. No dosage adjustment is necessary for patients with mild hepatic impairment, although increased accumulation may occur in patients with moderate to severe hepatic impairment, and in such cases a lower or less frequent dose may be considered.

Key safety warnings

In patients with metastatic prostate cancer, treatment with bicalutamide monotherapy has been associated with reduced survival compared to castration, and bicalutamide should therefore not be used without concomitant LHRH agonist therapy in these patients. Rare cases of death or hospitalisation due to severe liver injury have been observed with bicalutamide, and bicalutamide therapy should be discontinued if at any time a patient develops jaundice or if serum ALT rises above two times the upper limit of normal. A reduction in glucose tolerance has been observed in males receiving LHRH agonists, which may manifest as diabetes or loss of glycaemic control in those with pre-existing diabetes, and consideration should therefore be given to monitoring blood glucose in patients receiving bicalutamide in combination with LHRH agonists. Potentiation of coumarin anticoagulant effects have been reported in patients receiving concomitant bicalutamide therapy, which may result in increased Prothrombin Time (PT) and International Normalised Ratio (INR), and some cases have been associated with risk of bleeding, so close monitoring of PT/INR is advised and anticoagulant dose adjustment should be considered. Androgen deprivation therapy may prolong QT/QTc interval, and prescribers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities and in patients taking drugs known to prolong the QT interval; electrolyte imbalances should be corrected and periodic monitoring of electrocardiograms and electrolytes should be considered.

Contraindications

Bicalutamide is contraindicated in females and children. It is contraindicated in patients with known hypersensitivity to bicalutamide or any other constituents of the formulation. Co-administration of terfenadine, astemizole or cisapride with bicalutamide is contraindicated.

PBS listing

COSUDEX 50 mg tablet is listed on the PBS as one item with streamlined restriction at an ex-manufacturer price of A$36.35.

Regulatory history

COSUDEX bicalutamide 50 mg tablet was first registered on the ARTG on 1 July 1996.