Drug toxicity refers to the extent of harm that a compound can motive to an organism. The toxic outcomes of a drug are dose-structured and can influence an entire system as in the CNS or a selected organ consisting of the liver. Toxicity refers to how toxic or harmful a substance may be. inside the context of pharmacology, drug toxicity happens whilst someone has accrued an excessive amount of a drug in his bloodstream, leading to destructive effects at the body. Drug toxicity can be a major factor limiting the usefulness of widely used agents. The incidence of adverse drug reactions in patients who have HIV infection varies with the type of drug and dosages used, the interactions between drugs and the stage of HIV infection. HIV-related idiosyncratic factors, organ dysfunction in late-stage disease and multiple drug therapy are the primary reasons for the increased risk of drug toxicities in HIV patients.The issue of drug interactions has become particularly critical in the era of protease inhibitors. However, although the number of potential drug interactions is substantial, few require dosage modifications. Among these, clinicians should be vigilant when using concomitant prophylaxis and treatment of mycobacterial diseases with rifamycin, macrolides and HIV protease inhibitors.
Toxicity has been estimated to be responsible for the attrition of ~ 1/3 of drug candidates and is a major contributor to the high cost of drug development, particularly when not recognized until late in the clinical trials or post-marketing. The causes of drug toxicity can be organized in several ways and include mechanism-based (on-target) toxicity, immune hypersensitivity, off-target toxicity, and bioactivation/covalent modification. In addition, idiosyncratic responses are rare but one of the most problematic issues; several hypotheses for these have been advanced. Although covalent binding of drugs to proteins was described almost 40 years ago, the significance to toxicity has been difficult to establish; recent literature in this field is considered. The development of more useful biomarkers and short-term assays for rapid screening of drug toxicity early in the drug discovery/development process is a major goal, and some progress has been made using “omics” approaches.