Linezolid Induced Adverse Drug Reactions - An Update.

Treatment regimen recommended for resistant tuberculosis consists of various drugs and these drugs are prescribed for at least 12-15 months. Such a long duration therapy and high dose of antibiotics result in adverse drug reactions (ADRs). ADRs may lead to various complications in disease management like replacement of drugs, dose increment, therapy withdrawal, etc. Linezolid is one of those drugs, practiced as an anti-mycobacterial agent and it is an important member of drug regimen for MDR and XDR tuberculosis. Linezolid is a broad spectrum antibiotic known for its unique mechanism of inhibition of resistant pathogenic strains. However, it causes serious adverse effects like thrombocytopenia, optic neuropathy, peripheral neuropathy, lactic acidosis, etc. Literature suggests that Linezolid can cause severe ADRs which affect patient compliance and hinder in therapy to a larger extent. Recent studies confirm the possibility of ADRs to be predicted with genetic make-up of individuals. To effectively deliver the available treatment regimen and ensure patient compliance, it is important to manage ADRs more efficiently. The role of pharmacogenomics in reducing adverse drug effects has been recently explored. In the present review, we discussed about Linezolid induced adverse drug reactions, mechanisms and genetic associations.

Adverse Drug Reactions to Anti-TB Drugs: Pharmacogenomics Perspective for Identification of Host Genetic Markers.

Adverse drug reactions (ADRs) are associated with clinical morbidity and, in severe cases, even mortality. Globally billions of dollars are spent on managing these ADRs for common and uncommon diseases. The developing world suffers from a high burden of tuberculosis, which requires 6-8 months of multi-drug treatment. In spite of most cases being treatable the problem persists mainly due to a high attrition rate associated with ADR mediated complications. Due to these reasons drug resistant strains have emerged and are now a serious challenge to TB eradication. To effectively deliver the available treatment regimen and ensure patient compliance it is important to manage ADRs more efficiently. Recent studies have demonstrated that drug outcomes are patient-specific and can, therefore be predicted. A few of these drugs, including a few administered for TB, have shown excellent correlation with response rates and development of ADRs. In this review, we profile information available in public domain for existing anti-TB drugs to understand the genesis of ADRs and patient response. Additionally, human genome variation databases have been used to correlate the frequency of these markers and their genomic variants in different populations.

Photochemical toxicity of drugs intended for ocular use.

The present investigation was undertaken to evaluate the possible ocular phototoxicity of drugs used in ophthalmic formulations. Sulphacetamide, ketoconazole, voriconazole, diclofenac, and ketorolac were assessed in the concentrations available in the market for their ocular use. The suitable models viz Hen's Egg Test Chorioallantoic Membrane (HET-CAM) test, Isolated Chicken Eye (ICE) test, and Red Blood Cell (RBC) haemolysis test as recommended by ECVAM, ICCVAM, and OECD guidelines were performed. Results of HET-CAM and ICE tests suggest that sulphacetamide is moderately toxic in the presence of light/UV-A and very slightly irritant without irradiation. Ketoconazole and voriconazole were found slightly irritant in presence of light/UV-A and non-irritant in dark. Diclofenac and ketorolac demonstrated slight irritancy in the light and were found to be non-irritant in dark. The results suggest that some of the drugs have potential toxic effect in the presence of light. The extent of phototoxicity might get extended when used for longer time. The recommendation is that these drugs should be stored and used in the dark for a specified time and be labelled with specific instructions for patients, especially for those working longer in the sunlight.