Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Paludrine (ICI Pharmaceuticals)
100 mg tablets
Indication: malaria prophylaxis
This product is returning to the Australian market after an absence of 10 years. The use of proguanil declined as longer acting drug combinations such as dapsone/pyrimethamine and sulfadoxine/pyrimethamine became available. Recent concern about the adverse effects of these combinations has resulted in an increased demand for proguanil. As Plasmodium falciparum is now resistant to proguanil in many areas of Africa and South East Asia, the World Health Organization recommends that patients taking proguanil should also take chloroquine.
Proguanil is taken daily starting at least one day before entering the malarious area and continuing until 4 weeks after leaving the area. The drug is metabolised to the active antimalarial cycloguanil. This inhibits the synthesis of nucleic acids by the malaria parasite. The main effect of the drug is against pre-erythrocytic schizonts. Proguanil and cycloguanil are predominantly renally excreted, so the dose should be lowered in patients with reduced renal function.
In contrast to some of the other drugs used for prophylaxis, proguanil can be used by pregnant women and children.
The drug is usually well tolerated, the commonest adverse effects are gastrointestinal upsets and mouth ulcers. Patients who are anticoagulated may need to have their treatment adjusted when they commence proguanil.
It is anticipated that a working party of the National Health and Medical Research Council will consider the role of proguanil for Australian travellers.