Chloroquine is grossly under dosed in young children with malaria : implications for drug resistance

Background: Plasmodium falciparum malaria is treated with 25 mg/kg of chloroquine (CQ) irrespective of age. Theoretically, CQ should be dosed according to body surface area (BSA). The effect of dosing CQ according to BSA has not been determined but doubling the dose per kg doubled the efficacy of CQ in children aged <15 years infected with P. falciparum carrying CQ resistance causing genes typical for Africa. The study aim was to determine the effect of age on CQ concentrations. Methods and Findings: Day 7 whole blood CQ concentrations were determined in 150 and 302 children treated with 25 and 50 mg/kg, respectively, in previously conducted clinical trials. CQ concentrations normalised for the dose taken in mg/kg of CQ decreased with decreasing age (p<0.001). CQ concentrations normalised for dose taken in mg/m(2) were unaffected by age. The median CQ concentration in children aged <2 years taking 50 mg/kg and in children aged 10-14 years taking 25 mg/kg were 825 (95% confidence interval [CI] 662-988) and 758 (95% CI 640-876) nmol/l, respectively (p = 0.67). The median CQ concentration in children aged 10-14 taking 50 mg/kg and children aged 0-2 taking 25 mg/kg were 1521 and 549 nmol/l. Adverse events were not age/concentration dependent. Conclusions: CQ is under-dosed in children and should ideally be dosed according to BSA. Children aged <2 years need approximately double the dose per kg to attain CQ concentrations found in children aged 10-14 years. Clinical trials assessing the efficacy of CQ in Africa are typically performed in children aged <5 years. Thus the efficacy of CQ is typically assessed in children in whom CQ is under dosed. Approximately 3 fold higher drug concentrations can probably be safely given to the youngest children. As CQ resistance is concentration dependent an alternative dosing of CQ may overcome resistance in Africa.

Changes in the prevalence of breast feeding in preterm infants discharged from neonatal units : a register study over 10 years

Objective: There are indications that the prevalence of exclusively breastfed preterm infants is decreasing in Sweden. The objective was to investigate trends in exclusive breast feeding at discharge from Swedish neonatal units and associated factors in preterm infants. Design, setting and participants: This is a register study with data from the Swedish Neonatal Quality Register. Data from 29 445 preterm infants (gestational age (GA) <37 weeks) who were born during the period 2004–2013 were retrieved. Data included maternal, perinatal and neonatal characteristics. Data were analysed for the whole population as well as for 3 GA groups. Results: From 2004 to 2013, the prevalence of exclusive breast feeding decreased, in extremely preterm (GA 22–27 weeks) from 55% to 16%, in very preterm (GA 28–31 weeks) from 41% to 34% and in moderately preterm infants (GA 32–36 weeks) from 64% to 49%. The decline was statistically significant (p<0.001) in all 3 GA groups. This decline remained significant when adjustments were made for factors negatively associated with exclusive breast feeding and which became more prevalent during the study period, that is, small for GA (all groups) and maternal mental illness (very preterm and moderately preterm infants). Conclusions: In the past 10 years, Sweden has experienced a lower rate of exclusive breast feeding in preterm infants, especially in extremely preterm infants. The factors analysed in this study explain only a small proportion of this decline. The decline in exclusive breast feeding at discharge from neonatal units raises concern and present challenges to the units to support and promote breast feeding.