Chloroquine and non-malaria disorders

As well as for malaria, chloroquine is also used for a number of other disorders: rheumatoid arthritis, polymorphous light eruption, discoid lupus erythematosus, cutaneous sarcoidosis, hepatic amoebiasis, Q fever, cutaneous porphyria tarda etc. Chloroquine also exerts direct antiviral effects by inhibiting pH-dependent steps of the replication of several coronaviruses, Borna virus, Mayaro virus and retroviruses (there is even a very modest anti-HIV activity). Chloroquine inhibits the uncoating of hepatitis A virus. Certain flaviviruses will be inhibited by affecting the normal proteolytic processing of the flavivirus prM protein (precursor of membrane protein). Chloroquine has immunomodulatory properties, such as suppressing the production and release of TNF-alpha and interleukin-6.

Example:

The porphyrias are a group of disorders characterised by disturbed production of haem. Most are autosomal dominant and inherited, and there is quite variable expression of the disease. Porphyria cutanea tarda can also be acquired, however, (oestrogens and excessive alcohol play an important role). The disorder generally becomes evident around the age of 40 to 50 and is characterised by hepatic abnormalities and significant skin fragility (chiefly the hands, legs and face. Blisters, erosions and scabs appear on skin exposed to sunlight. A very dark skin (hyperpigmentation) with sclerodermoid changes may occur. It is important for the patient to stop drinking alcohol, and to avoid oestrogen and iron preparations. Hepatic siderosis is generally present and repeated phlebotomies are indicated (400-500 ml every 1 or 2 weeks, until Hb <>

Category: Pharmacology Notes