Doxorubicin hydrochloride (Caelyx)

Doxorubicin hydrochloride is an approved anti-cancer drug, which is injected into a vein. It has significant side-effects.

Doxorubicin is thought to act by binding to DNA and inhibiting the manufacture of DNA or ribonucleic acid (RNA) molecules. It is active, alone or in combination, against a wide spectrum of tumours, including non-Hodgkin’s lymphoma and breast cancer.

The commonest side-effect that requires recipients to reduce the dose or stop taking the drug is blood abnormalities, usually leukopenia, a low number of leukocytes in the blood. Other side-effects can include heart toxicity, hair loss, nausea, vomiting and oral ulcers.

Doxorubicin is manufactured by Pharmacia & Upjohn, and was formerly known by the trade name Adriamycin.

A formulation of doxorubicin in which the drug has been encased in fatty particles called liposomes has also been licensed. This liposomal doxorubicin is better targeted to tumour cells as opposed to healthy cells and so may be more effective with fewer side-effects.¹ This formulation is licensed for various types of cancer, including Kaposi’s sarcoma, alone or in combination with antiretroviral therapy, in patients with CD4 cell counts below 200 cells/mm³ who have extensive disease.

There is disagreement over the degree of effectiveness of liposomal doxorubicin. In data presented to the United States Food and Drug Administration (FDA), the manufacturer claimed that 68% of recipients experienced at least a partial response. However, the FDA considered that the effects of the drug in some recipients could not be properly analysed, and by their assessment only 27% had a partial response. Despite these reservations, this drug has now been approved in the United States and the European Union.

Side-effects of liposomal doxorubicin can include mouth inflammation, hair loss, nausea and blood toxicities. One case of fatal liver failure in a person with a history of symptom-free hepatitis B was attributed to liposomal doxorubicin.²

Liposomal doxorubicin is manufactured by Sequus Pharmaceuticals Inc under the trade names Caelyx and Myocet in Europe, and Doxil in the United States. It is also sometimes referred to at DOX-SL. In Europe it is marketed by Schering-Plough Corporation and Medeus Pharma Ltd.

Doxorubicin is not known to interact with any anti-HIV drugs.³