No further relapse was observed. Compliance to treatment was declared suboptimal (85%) in one case (first course). One patient reported dizziness and headache (first and only course), but took all his dosages.
All patients completed the course of primaquine despite presumed side effects. No significant variations were observed in hematologic and biochemistry parameters (eight patients assessed before and after therapy). Inhibitor Library nmr Active surveillance was unsuccessful in six cases, including two relapsing cases. No further relapse was detected in eight patients. Primaquine was first synthesized six decades ago but remains the only effective treatment for the hypnozoites of P ovale and P vivax. The aggravated hematotoxicity of primaquine in G6PD-deficient patients as well as the low oral bioavailability of the compound have been obstacles to its widespread use. The anti-relapse efficacy of primaquine depends not only on the timing of radical cure and patient compliance but also on the dosage of the prescribed regimen. The initial standard recommended regimen for primaquine was 15 mg/day for 14 days. However, full elimination of the hypnozoites of some P vivax strains was shown to require a daily dose of 30 mg. The report from the Centers for Disease Control and Prevention (CDC) expert
meeting on malaria buy BVD-523 in 2006 recommends a presumptive anti-relapse therapy at doses of 30 mg daily for 14 days with an expected efficacy of about 95%. The formerly recommended daily primaquine dosage of 15 mg/day has been used in the three adult patients treated for P ovale infections during the study period and no further relapse was observed. This may reflect the lower trend of P ovale infections compared with P vivax to relapse after a radical cure. To our knowledge, only five case reports of treatment failure with unsupervised primaquine in P ovale malaria have been published in the English scientific literature, among which primaquine total dose/kg was available
in four cases. In three cases, total dose ranged between 2.5 and 3 mg/kg PtdIns(3,4)P2 (from Ghana, Nigeria, and Ethiopia). One relapse from Uganda was observed after a 5 mg/kg total dose (45 mg weekly for 6 weeks). As illustrated by this study, relapses occur in the case of P vivax infections. These relapses could be attributed to poor compliance, which cannot be ruled out, but this also applies to the weight-adapted regimen. Plasmodium vivax sensitivity to primaquine differs from one geographic area to another. Studies performed on P vivax strains from Ethiopia and Brazil showed that primaquine total doses >3.5 mg/kg were successful,[8, 9] while another study based on P vivax strains from Oceania stated that 6 mg/kg of primaquine was the appropriate total dose for radical cure. The pattern and probability of relapse also varies according to the geographical origin of malaria infection.