Pharmacokinetics, feasibility and safety of co-administering azithromycin, albendazole, and ivermectin during mass drug administration: A review

Marine Natural Products as Novel Treatments for Parasitic Diseases

Parasitic diseases including malaria, leishmaniasis, and trypanosomiasis have received significant attention due to their severe health implications, especially in developing countries. Marine natural products from a vast and diverse range of marine organisms such as sponges, corals, molluscs, and algae have been found to produce unique bioactive compounds that exhibit promising potent properties, including antiparasitic, anti-Plasmodial, anti-Leishmanial, and anti-Trypanosomal activities, providing hope for the development of effective treatments. Furthermore, various techniques and methodologies have been used to investigate the mechanisms of these antiparasitic compounds. Continued efforts in the discovery and development of marine natural products hold significant promise for the future of novel treatments against parasitic diseases.

Drug repurposing for bacterial infections

Repurposing pharmaceuticals is a technique used to find new, alternate clinical applications for approved drug molecules. It may include altering the drug formulation, route of administration, dose or the dosage regimen. The process of repurposing medicines starts with screening libraries of previously approved drugs for the targeted disease condition. If after an the initial in silico, in vitro or in vivo experimentation, the molecule has been found to be active against a particular target, the molecule is considered as a good candidate for clinical trials. As the safety profile of such molecules is available from the previous data, significant time and resources are saved. These advantages of drug repurposing approach make it especially helpful for finding treatments for rapidly evolving conditions including bacterial infections. An ever-increasing incidence of antimicrobial resistance, owing to the mutations in bacterial genome, leads to therapeutic failure of many approved antibiotics. Repurposing the approved drug molecules for use as antibiotics can provide an effective means for the combating life-threatening bacterial diseases. A number of drugs have been considered for drug repurposing against bacterial infections. These include, but are not limited to, Auranofin, Closantel, and Toremifene that have been repurposed for various infections. In addition, the reallocation of route of administration, redefining dosage regimen and reformulation of dosage forms have also been carried out for repurposing purpose. The current chapter addresses the drug discovery and development process with relevance to repurposing against bacterial infections.

Quantifying the fitness effects of resistance alleles with and without anthelmintic selection pressure using Caenorhabditis elegans

Albendazole (a benzimidazole) and ivermectin (a macrocyclic lactone) are the two most commonly co-administered anthelmintic drugs in mass-drug administration programs worldwide. Despite emerging resistance, we do not fully understand the mechanisms of resistance to these drugs nor the consequences of delivering them in combination. Albendazole resistance has primarily been attributed to variation in the drug target, a beta-tubulin gene. Ivermectin targets glutamate-gated chloride channels (GluCls), but it is unknown whether GluCl genes are involved in ivermectin resistance in nature. Using Caenorhabditis elegans, we defined the fitness costs associated with loss of the drug target genes singly or in combinations of the genes that encode GluCl subunits. We quantified the loss-of-function effects on three traits: (i) multi-generational competitive fitness, (ii) fecundity, and (iii) development. In competitive fitness and development assays, we found that a deletion of the beta-tubulin gene ben-1 conferred albendazole resistance, but ivermectin resistance required the loss of two GluCl genes (avr-14 and avr-15). The fecundity assays revealed that loss of ben-1 did not provide any fitness benefit in albendazole conditions and that no GluCl deletion mutants were resistant to ivermectin. Next, we searched for evidence of multi-drug resistance across the three traits. Loss of ben-1 did not confer resistance to ivermectin, nor did loss of any single GluCl subunit or combination confer resistance to albendazole. Finally, we assessed the development of 124 C. elegans wild strains across six benzimidazoles and seven macrocyclic lactones to identify evidence of multi-drug resistance between the two drug classes and found a strong phenotypic correlation within a drug class but not across drug classes. Because each gene affects various aspects of nematode physiology, these results suggest that it is necessary to assess multiple fitness traits to evaluate how each gene contributes to anthelmintic resistance.