Pharmacokinetics of two paediatric artesunate mefloquine drug formulations in the treatment of uncomplicated falciparum malaria in Gabon

OBJECTIVES

Paediatric drug formulations of artemisinin combination therapies and pharmacokinetic data supporting their use in African children are urgently needed for the effective treatment of young children suffering from falciparum malaria in sub-Saharan Africa.

PATIENTS AND METHODS

In this study, the pharmacokinetic characteristics of a novel paediatric granule formulation of artesunate-mefloquine therapy were evaluated in comparison to the standard tablet formulation in the treatment of uncomplicated malaria in paediatric patients. Twenty-four patients were assigned to treatment according to body weight with either a fixed-dose paediatric granule co-formulation (10-20 kg body weight) or a free-dose co-blister tablet formulation of artesunate-mefloquine (>20-40 kg body weight).

RESULTS

Median values for C(max) (861 and 930 ng/mL), T(max) (1.5 and 1.5 h) and AUC(0-)(t) (2,050 and 2,470 ng.h/mL) were comparable for dihydroartemisinin in the two groups. Exploratory analysis of mefloquine plasma levels revealed a trend towards higher concentrations in the younger age group during the absorption phase (2,550 and 1,815 ng/mL, 54 h after initiation of treatment, respectively). Median mefloquine concentrations at day 28 were 197 and 343 ng/mL, respectively.

CONCLUSIONS

The pharmacokinetic characteristics of the two paediatric dosage forms, i.e. the novel fixed-dose co-formulation and the standard co-blister of artesunate-mefloquine show comparable results in the two treatment groups. The novel fixed-dose paediatric formulation is an interesting option for outpatient treatment of uncomplicated malaria in African children.

Assessment of the effect of mefloquine on artesunate pharmacokinetics in healthy male volunteers

The effect of mefloquine on artesunate pharmacokinetics was assessed in 20 volunteers given artesunate for 3 days, followed > or =21 days later by combination therapy for 3 days. The areas under the concentration-time curve from 0 h to infinity for dihydroartemisinin, the active metabolite of artesunate, were similar on day 3 of the two dosing periods (P = 0.12), implying no interaction.

Diclofenac patch for topical treatment of acute impact injuries: a randomised, double blind, placebo controlled, multicentre study

OBJECTIVES

To investigate the clinical efficacy and safety of a newly developed diclofenac patch in the topical treatment of blunt impact injuries.

METHODS

This was a randomised, placebo controlled, double blind, multicentre study in 120 patients with traumatic blunt soft tissue injury. Within 3 h of the injury participants of sport competitions and training camps were enrolled and treated twice daily with the diclofenac or a placebo patch over a period of 7 days. Patients were randomised (1:1) to two parallel groups. Tenderness produced by pressure was measured twice daily during the first 3 days after enrollment as well as at day 7. Tenderness was defined as the amount of pressure (measured by a calibrated caliper at the centre of the injury) that first produced a pain reaction as reported by the patient.

RESULTS

The primary efficacy variable was the area under the curve for tenderness over the first 3 days. The diclofenac patch was significantly more effective than placebo (p<0.0001). The treatment effect was 64.7 kp h/cm2 (95% confidence interval 48.7 to 80.9) between diclofenac and placebo patches. These results were supported by all secondary efficacy variables. The diclofenac patch produced rapid pain relief as reflected by the time to reach resolution of pain at the injured site which was significantly shorter compared to placebo (p<0.0001). The diclofenac patch was well tolerated. The most frequently observed adverse events were local cutaneous adverse reactions (pruritus, rash) of minor severity occurring with the same frequency as in the placebo group.

CONCLUSIONS

A newly developed diclofenac patch is effective and safe for the treatment of blunt impact injuries.

[Relative bioavailability of an optimised galenical formulation of mefloquine]

The bioequivalence of an optimised formulation of a generic mefloquine (Mephaquin Lactabs/Test) compared to the reference product under fed conditions was assessed in a GCP/ICH conformable study. A standard two-way randomised crossover design with a 9 week washout period between treatments was used. Blood samples for determination of mefloquine concentrations for calculation of Cmax and AUC were collected at pre-dose and at predefined intervals up to 2016 hours after administration of a single oral dose of 750 mg. A standard bioequivalence analysis was performed on the two one-sided t-test procedure for log-transformed Cmax and AUC. 90% confidence intervals were calculated for both parameters and evaluated against regulatory standards of 80-125% (T/R). Analysis of plasma for mefloquine concentration was performed using a validated LC/MS method with MS detection. The ratio of mean AUC and Cmax (T/R) was 1.015 and 1.044, respectively. The 90% confidence intervals were 95.8-109.3% for AUC and 98.2-110.5% for Cmax. Mephaquin produces plasma concentrations comparable to those after administration of the reference product. The 90% confidence intervals for AUC and Cmax are within the acceptable ranges for bioequivalence of 80-125%. Thus, the optimised galenical formulation of Mephaquin Lactabs is bioequivalent to the reference product.

[Topical treatment of blunt-impact soft tissue injuries]

Studies have shown that topical NSAIDs, e.g. diclofenac, easily penetrate the skin barrier to exert local therapeutic activity. In contrast to oral administration, plasma levels after application of topical formulations are by several magnitudes lower thus explaining the lack of systemic side effects. We discuss the clinical relevance of patches containing an NSAID by demonstrating the efficacy and safety of a newly developed diclofenac patch in the topical treatment of blunt impact soft tissue injuries in a randomised, placebo controlled, double blind, multicentre study. The results showed that the diclofenac patch was significantly more effective than placebo (p < 0.0001) with a significantly faster pain relief. The diclofenac patch was well tolerated. It might be used in indications with similar pathomechanisms.