Clinical-parasitological response and in-vitro sensitivity of Plasmodium vivax to chloroquine and quinine on the western border of Thailand

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene Vol. 100; no. 5; pp. 410 - 418
• Main Authors: Tasanor, Oumaporn, Ruengweerayut, Ronnatrai, Sirichaisinthop, Jeerapat, Congpuong, Kanungnit, Wernsdorfer, Walther H., Na-Bangchang, Kesara
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.05.2006; Royal Society of Tropical Medicine and Hygiene; Elsevier
• Subjects: Adolescent; Adult; Animals; Antimalarials - blood; Antimalarials - therapeutic use; Biological and medical sciences; Chloroquine; Chloroquine - blood; Chloroquine - therapeutic use; Drug Resistance; Female; Human protozoal diseases; Humans; In-vitro sensitivity; Infectious diseases; Malaria; Malaria, Vivax - blood; Malaria, Vivax - drug therapy; Male; Medical sciences; Middle Aged; Myanmar; Parasitic diseases; Parasitic Sensitivity Tests; Plasmodium vivax; Plasmodium vivax - drug effects; Primaquine; Protozoal diseases; Quinine; Quinine - blood; Quinine - therapeutic use; Thailand; Thailand; Asia; Myanmar; Plasmodium vivax; In-vitro sensitivity; Thailand; Primaquine; Quinine; Chloroquine; Human; Protozoa; Antimalarial; Apicomplexa; Protozoal disease; Malaria; Drug susceptibility test; Parasitosis; In vitro; Infection; In vivo; Sensitivity; Antipyretic; Parasiticide; Tropical medicine; Antirheumatic agent
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/j.trstmh.2005.04.024

This study was conducted during 2002–2004 at Mae Sot District, on the Thai–Myanmar border, an area of multidrug-resistant Plasmodium falciparum malaria. Sixty-two patients with P. vivax malaria were included in the study. All were randomized into two groups to receive a 3-day regimen of chloroquine or a 3-day regimen of quinine. Primaquine was given to patients in both groups for the elimination of hepatic stages. Results from the present study suggest that the standard regimen of chloroquine and a 3-day course of quinine at the dose regimens under investigation were very effective and well tolerated for the treatment of P. vivax malaria in this area. All patients responded well to both drug regimens; the cure rates with chloroquine or quinine, when given concurrently with the tissue schizontocidal drug primaquine, were virtually 100% within 28 days of follow-up. No significant correlations between parasite clearance time (PCT) or fever clearance time (FCT) and inhibitory concentration 50 (IC 50) were found. Patients who had PCT ≤24 h and those with PCT >24 h had comparable IC 50 to chloroquine (alone and plus primaquine) and quinine, as well as similar concentrations of chloroquine/desethylchloroquine (in blood) or quinine (in plasma) at the investigated time points.