Immunotoxicity: is defined as a condition in which an immunotoxin negatively affects the immune system. An immunotoxin is a human-made protein consisting of a protein bound to a toxin. The protein works by “targeting” specific cells, which are killed when the protein binds to those cells and the toxin is absorbed through a process called “endocytosis.” Immunotoxicity includes direct toxicity to components of the immune system, resulting in suppression of function or inadvertent stimulation. The immune system is made up of a complex network of cells and soluble mediators that interact in a highly regulated manner to generate immune responses, consequently inappropriate immune responses could lead to allergic and autoimmune diseases.NSAIDs:NSAIDs (nonsteroidal anti-inflammatory drugs) have antipyretic and anti-inflammatory in different measures. They act mainly on peripheral pain mechanisms and do not cause physical dependence or depress the central nervous system. Although the risk of adverse effects related to NSAIDs increases with long-term use, they represent a reliable and effective treatment for the control of moderate pain. The most common NSAIDs are aspirin, phenylbutazone, diclofenac, paracetamol, ibuprofen and ketoprofen. Few NSAIDs and their structures: Aspirin Uses: Furthermore, having regular antipyretic and anti-inflammatory effects, it is believed to have antioxidant effects (Ataollah, 2011 ) through its ability to scavenge OH radicals. Ibuprofen: Uses: Migraine treatment (Evers, 2011) Paracetamol: Uses: The most common household medication Mechanism: There are different types of cyclooxygenase (COX) enzymes in...... middle of paper ......Pregnancy early linked to risk of miscarriage, Canadian Medical Association Journal, 110454.4. Mennear, John H, White, Kimber L,; Komocsar, Wendy J.; Khan, K. Nasir;. Jr.; Furst, Sylvia M.; Peachee, Vanessa L.; Screening drugs for immunotoxic potential: I. Evaluation of the effects of conventional nonsteroidal anti-inflammatory drugs and selective COX-2 inhibitors on phagocytic activity in vitro and in vivo, 2004, Vol-1,149-158.5. Kushima, Kiyoshi; Fujiwara, Michigan; Oda, Keiko; Sakuma, Shozo; Furusawa, Shuichi; Effect of prenatal administration of NSAIDs on the immune response in youth and adults, 2007, Vol-232,257-267.6. PanahYab, Ataollah; Bagheri Sadeghi, Golshan; Nafisi, Shohreh; Interaction of aspirin and vitamin C with bovine serum albumin,2011,105,198-202.7. Husstedt, I.W.; Evers, S. Migraine during pregnancy and breastfeeding, 2011, 44, 969-973