Rapid clearance of Plasmodium falciparum hyperparasitaemia after oral amodiaquine treatment in patients with uncomplicated malaria

Prognostic value of clinical and parasitological signs for severe malaria in patients from Colombia

Introducción. El pronto reconocimiento de los signos de peligro en los pacientes con malaria puede reducir las complicaciones y muertes. Sin embargo, se conoce poco sobre su valor pronóstico para la malaria complicada, especialmente en las zonas de transmisión baja e inestable de la enfermedad.Objetivo. Estimar el valor pronóstico de gravedad que tienen diversos signos clínicos y parasitológicos en los pacientes con malaria.Materiales y métodos. Se hizo un estudio en una cohorte prospectiva con pacientes de cinco municipios de Colombia, con diagnóstico de malaria por Plasmodium falciparum y P. vivax, en quienes se estudió la asociación de los signos clínicos y los parasitológicos con la malaria complicada.Resultados. Se obtuvo un modelo de predicción con una sensibilidad de 47,4 % y especificidad de 92,8 %, valor pronóstico positivo de 63,2 % y valor pronóstico negativo de 87,1 %, el cual incluye ictericia, orina oscura, hiperpirexia y signos de deshidratación.Conclusiones. Con el fin de causar un impacto en la morbilidad complicada de la malaria, se propone una estrategia de reconocimiento de los signos de peligro por el personal no médico, que se acompañede otros elementos de la atención, como el suministro de un tratamiento antipalúdico adecuado y oportuno. Se proponen los criterios del diagnóstico de complicación moderada.

Rifampicin/Cotrimoxazole/Isoniazid versus mefloquine or quinine + sulfadoxine- pyrimethamine for malaria: a randomized trial

OBJECTIVES

Previous studies of a fixed combination including cotrimoxazole, rifampicin, and isoniazid (Cotrifazid) showed efficacy against resistant strains of Plasmodium falciparum in animal models and in small-scale human studies. We conducted a multicentric noninferiority trial to assess the safety and efficacy of Cotrifazid against drug-resistant malaria in Papua New Guinea.

DESIGN

The trial design was open-label, block-randomised, comparative, and multicentric.

SETTING

The trial was conducted in four primary care health facilities, two in urban and two in rural areas of Madang and East Sepik Province, Papua New Guinea.

PARTICIPANTS

Patients of all ages with recurrent uncomplicated malaria were included.

INTERVENTIONS

Patients were randomly assigned to receive Cotrifazid, mefloquine, or the standard treatment of quinine with sulfadoxine-pyrimethamine (SP).

OUTCOME MEASURES

Incidence of clinical and laboratory adverse events and rate of clinical and/or parasitological failure at day 14 were recorded.

RESULTS

The safety analysis population included 123 patients assigned to Cotrifazid, 123 to mefloquine, and 123 to quinine + SP. The Cotrifazid group experienced lower overall incidence of adverse events than the other groups. Among the efficacy analysis population (72 Cotrifazid, 71 mefloquine, and 75 quinine + SP), clinical failure rate (symptoms and parasite load) on day 14 was equivalent for the three groups (0% for Cotrifazid and mefloquine; 1% for quinine + SP), but parasitological failure rate (P. falciparum asexual blood-stage) was higher for Cotrifazid than for mefloquine or quinine + SP (9% [PCR corrected 8%] versus 0% and 3%, respectively [p = 0.02]).

CONCLUSION

Despite what appears to be short-term clinical equivalence, the notable parasitological failure at day 14 in both P. falciparum and P. vivax makes Cotrifazid in its current formulation and regimen a poor alternative combination therapy for malaria.

Pharmacodynamic interactions of amodiaquine and its major metabolite desethylamodiaquine with artemisinin, quinine and atovaquone in Plasmodium falciparum in vitro

The antimalarial in vitro activities of amodiaquine and desethylamodiaquine in combination with atovaquone, quinine and artemisinin against Plasmodium falciparum were investigated in strains F-32, FCR-3 and K-1. These parasitic strains have different sensitivity profiles to the standard antimalarial chloroquine, but all can be considered sensitive to the test drugs, representing the recommended situation for introduction of two partner drugs in combination therapy. Amodiaquine showed marked synergism when combined with each of the three partner compounds at concentration ratios between 90 and 9x10(-7), including the therapeutically relevant range. The interaction profiles of desethylamodiaquine with quinine and artemisinin also showed predominantly synergism over a wide range of concentration ratios between 70 and 9x10(-7). The responses to all combinations exhibited signs of strain-specificity, but such phenomena were usually observed outside the therapeutic range of the concentration ratios. Synergism was generally more marked with increasing EC values, i.e. at concentrations expected to be therapeutically effective and thus clinically relevant. Even trace quantities of amodiaquine were able to potentiate the activity of structurally unrelated antimalarial drugs.