Broadstairs College

Combination medicines including an artemisinin are the mainstay of antimalarial therapy. Artemisinins are potent embryotoxicants in animal species due to their trioxane moiety. As part of its development, the new synthetic trioxolane antimalarial artefenomel (OZ439) was tested in rat whole embryo culture and in rat embryo-fetal toxicity studies with dosing throughout organogenesis or with a single dose on Gestational Day (GD) 12. The single-dose studies included groups treated with artesunate to allow a direct comparison of the embryotoxicity of the two antimalarials and included toxicokinetics hematology and histological examination of embryos. In addition, the distribution of artefenomel-related material in plasma was determined after the administration of 14 C-artefenomel. Artefenomel and artesunate showed similar patterns of embryotoxicity including cardiovascular defects and resorption with a steep dose-response. They both also caused a depletion of circulating embryonic erythroblasts both in vitro and in vivo and decreases in maternal reticulocyte count. However, artefenomel was ∼250-fold less potent than the active metabolite of artesunate (dihydroartemisinin) as an embryotoxicant in vitro. The safety margin (based on AUC) for artefenomel administered on GD 12 was approximately 100-fold greater than that for artesunate. Also, unlike artesunate, artefenomel was not a selective developmental toxicant. The lesser embryotoxicity of artefenomel is likely linked to its original design which included two blocking side groups that had been introduced to lower the reactivity with ferrous iron. Our data support the hypothesis that artefenomel's improved safety margin is linked to a lower potential for inhibiting heme biosynthesis in embryonic erythroblasts.

I recently attended a clinical commissioning group (CCG) 'consultation' in Kent. It was held in a church building at the back of a remote industrial estate.

This chapter contains sections titled: Membrane Transfer Access to the Target Brain Penetration References

The efficacy of voriconazole against fungal central nervous system (CNS) infections was examined retrospectively. Voriconazole-treated patients with proven (137) or probable (55) CNS infections were identified in the voriconazole database (114) and the literature (78). Investigator-determined success was a complete or partial response. Survival was calculated from the start of voriconazole therapy. The patients' age range was <1-81years (median 43) and 127 (66%) were male. Aspergillus spp. (63%) and Scedosporium spp. (18%) predominated, but 12 other genera were recorded. Underlying conditions were haematopoietic stem cell transplantation (HSCT, 35), haematologic malignancy (HM, 35), solid-organ transplantation (SOT, 25), chronic immunosuppression (CI, 40) and other conditions (OC, 57). The median voriconazole therapy duration was 93days (range 1-1,128), with success in 93 patients (48%). Only 35 patients received primary therapy, with success in 63% versus 45% for salvage (p=0.06 NS). Underlying conditions influenced success; HSCT 14%, HM 54%, SOT 40%, CI 45% and OC 72% (p<0.001). Additional antifungal combination therapy (37 patients) gave a trend towards an improved response rate (p=0.09) and superior survival (p=0.0149), while patients receiving neurosurgical interventions (72) showed superior responses (p=0.0174) and survival (p=0.0399). In all, 49% of patients died, 71% (67/94) due to fungal infection. The overall median survival was 297days (range 3 to >2,000). Paediatric (p=0.014) and literature patients (p<0.001) exhibited superior survival compared with adults and voriconazole database patients, respectively. Voriconazole shows encouraging efficacy against various CNS fungal infections. Combination therapy and/or CNS surgery may improve outcomes.

The outcomes for 73 invasive fusariosis patients treated with voriconazole were investigated. Patients with proven (n = 67) or probable (n = 6) infections were identified from the voriconazole clinical database (n = 39) and the French National Reference Center for Mycoses and Antifungals database (n = 34). Investigator-determined success was a complete or partial response. Survival was determined from day 1 of voriconazole therapy to the last day known alive. Patients were 2 to 79 years old (median, 43 years), and 66% were male. Identified Fusarium species (62%) were F. solani, F. moniliforme, F. proliferatum, and F. oxysporum. Underlying conditions analyzed included hematopoietic stem cell transplant (HSCT; 18%), hematologic malignancy (HM; 60%), chronic immunosuppression (CI; 12%), or other condition (OC; 10%). Infection sites were brain (5%), disseminated excluding brain (67%), lungs/sinus (15%), and other (12%). Most patients (64%) were or had recently been neutropenic (<500 cells/mm(3)). Therapy duration was 1 to 480 days (median, 57 days), with a 47% success rate. Baseline neutropenia impacted success adversely (P ≤ 0.03). Success varied by underlying condition (HSCT, 38%; HM, 45%; CI, 44%; OC, 71%) and infection site (brain, 0%; disseminated, 45%; other, 56%; lung/sinus, 64%) (P > 0.05). Combination therapy (13 patients) was no better than treatment with voriconazole alone. Overall, 59% of the patients died (49% died of fusariosis), and 90-day survival was 42%. Site of infection influenced survival (P = 0.02). Median survival (in days) by species was as follows: F. solani, 213; F. oxysporum, 112; Fusarium spp., 101; F. proliferatum, 84; F. moniliforme, 76. We conclude that voriconazole is a therapeutic option for invasive fusariosis.