Chloroquine use improves dengue-related symptoms

Borges, Marcos Carvalho; Castro, Luiza Antunes; da Fonseca, Benedito Antonio Lopes

We set up a double-blind, randomised study that administered either chloroquine or placebo (starch) to patients suspected of having dengue disease. Patients were included in the study if they presented with denguerelated symptoms, such as fever and at least two other symptoms, such as headache, retro-orbital pain, muscle and bone or joint pain, nausea, vomiting and rash, for less than 72 h. Patients were excluded if they were pregnant, younger than 18 years old or had either cardiac or neurologic disease. Once entered into the study, the patients were randomised in a double-blind fashion to receive either 500 mg chloroquine (300 mg base) BID or an identical-appearing placebo BID for three days (control group). In addition to the use of either chloroquine or placebo, both groups were similarly treated with hydration and symptomatic medication, such as analgesic and antipyretic drugs, according to medical prescription. Three diagnostic tests were performed according to well-defined protocols [reverse transcription-polymerase chain reaction, IgM antibody capture ELISA and the non structural 1 (NS1) antigen detection� on all the sam-antigen detection� on all the samples (Innis et al. 1989 , Lanciotti et al. 1992 , Dussart et al. 2006 , Castro-Jorge et al. 2010 . Dengue was confirmed when at least two diagnostic tests were positive. The patients were re-evaluated one week later and clinical data associated with dengue symptoms, such as fever, headache, retro-orbital pain, muscle, bone or joint pain, nausea and vomiting were recorded as well as symptoms related to the side effects of chloroquine. The axillary temperature was objectively measured and considered abnormal (fever) when ≥ 37.8ºC. Other variables were obtained actively and objectively during a medical consultation using a research form.