Mechanisms of toxicity

Mechanisms of toxicity

Just as drugs exert their pharmacological effect via a specific mechanism, toxic effects also follow from specific mechanisms. Drugs can evoke toxicity by binding to all kinds of biological molecules, e.g. lipids, proteins, and nucleic acids. This results in the formation of reactive macromolecules, onset of an immune response, or interference with cellular processes such as oxygen delivery, DNA replication,

gene expression, neurotransmission, etc. The cell can respond to damage by activating several repair mechanisms. If these fail, the cell undergoes necrosis or apoptosis. When many cells are affected by a drug or the toxicity continues over a longer period, the toxic effects can cause tissue and organ failure. Toxicity at the DNA level can result in carcinogenesis or teratogenesis.