Pharmacokinetics of primaquine in healthy volunteers.

The pharmacokinetics of primaquine were investigated in 8 healthy subjects (4 males and 4 females). The volunteers received 15 mg base of primaquine daily for 14 days. The results showed that the concentration-time profiles in whole blood and in plasma were similar. The mean values (+/- SD) of area under the curve (AUC) of the last dose were significantly decreased when compared to the values of the first dose both in whole blood and in plasma (909.96 +/- 603.07, 1,147.05 +/- 684.8 ng.hr/ml respectively in whole blood with p = 0.007 and 1,255.11 +/- 531.59, 1,603.66 +/- 505.45 ng.hr/ml respectively in plasma with p = 0.023). The decrease in the concentration-time profile of the last dose was due to enhancement of drug elimination with significant increase in clearance after the last dose (4.871 +/- 1.741 and 6.443 +/- 2.514 ml/min/kg respectively in whole blood with p = 0.007, 3.199 +/- 1.197 and 4.422 +/- 2.068 ml/min/kg respectively in plasma with p = 0.016).

Effect of single-dose albendazole and single-dose mebendazole on Necator americanus.

One hundred two children (43 males and 59 females) aged 6 to 14 years with positive stool examination by Kato-Katz and/or Harada-Mori culture techniques for N. americanus, were randomly divided into two groups. Group I with 48 children were treated with a single dose albendazole, 400 mg. Group II, 54 children, received a single dose mebendazole, 600 mg. After treatment, repeated stool examination was performed on Day 14, Day 21 and Day 28. The children were considered cured when stool examination was negative on all three occasions by both methods. The cure rate was 64% in Group I and 11% in Group II. The difference was statistically significant (p less than 0.05). The eggs reduction rate was 98% in Group I and 95% in Group II. Mild and transient side effects such as nausea, dizziness and headache were observed in both groups. Albendazole, 400 mg, as a single dose treatment was shown to be superior to mebendazole, 600 mg, single dose for the mass treatment of hookworm infection, especially that of Necator americanus, in an endemic area.

Comparative study of different doses of mebendazole in hookworm infection.

Sixty six children (40 males, 26 females) aged from 4 to 14 years with hookworm infection were treated with mebendazole. Thirty one and 35 children were treated with mebendazole 300 mg single dose and 600 mg conventional regimen respectively. Stool examination by Kato-Katz technique were done for 3 consecutive days before treatment and on day 14-16, 21-23 after treatment. The cure rate with 300 mg mebendazole was 16.1% with 90.9% egg reduction while 600 mg mebendazole gave 91.4% cure rate with 99.5% egg reduction. No side effects were observed in all children. Four hundred and six adult worms were identified, 99% were Necator Americanus, 0.5% Ancylostoma duodenale and 0.5% Ancylostoma ceylanicum.