Further Observations on the Use of 4-Aminoquinoline Compounds in Patients with Rheumatoid Arthritis or Related Diseases

Author and Disclosure Information


A NUMBER of investigators1–11 have reported that in patients with rheumatoid arthritis and allied diseases, clinical improvement occurs after administration of the 4-aminoquinoline compounds, chloroquine phosphate and hydroxychloroquine sulfate.** In a previous report11 the effect of hydroxychloroquine sulfate was compared with that of chloroquine phosphate in patients with rheumatoid arthritis. It was concluded that hydroxychloroquine sulfate in equal dosage caused fewer drug reactions than did chloroquine phosphate; however, in such dosage, hydroxychloroquine sulfate was less effective as an anti-inflammatory agent. The purpose of this report is to describe the results that were observed during the past three years in the administration of these compounds, alone or in combination with other agents, to 805 patients with rheumatoid arthritis or related diseases.

Drugs Used

Chloroquine phosphate is 7-chloro-4 (4-diethylamino-l-methylbutylamino) quinoline diphosphate. Hydroxychloroquine sulfate is 7-chloro-4-[4-(N-ethyl-N-β-hydroxyethylamino)-l-methylbutylamino] quinoline sulfate. The structural formulas are:

Hydroxychloroquine sulfate is similar to chloroquine phosphate except that a hydroxyethyl group has been substituted for an ethyl group on the tertiary amino nitrogen. Both drugs are almost completely absorbed from the gastrointestinal tract, although hydroxychloroquine sulfate apparently is absorbed more rapidly than is chloroquine phosphate. Considerable amounts of the drugs are found in the liver, spleen, kidneys, lungs, skin, and leukocytes, while the lowest concentration is in the central nervous system. Approximately 25 per cent of the oral daily dose is excreted in the urine, and after administration has been discontinued, the remainder of the drugs slowly undergoes metabolic degradation.

Selection of Patients

Of 805 patients treated with one. . .



Next Article: