Cyclooxygenase inhibitor

Inhibitors of cyclooxygenase are mostly non-steroidal anti-inflammatory drugs (NSAID). The majority of nonsteroidal anti-inflammatory drugs inhibit cyclooxygenases 1 and 2 relatively specifically, with the synthesis of all prostaglandins and thromboxanes occurring via these enzymes. The advantage of specific cyclooxygenase 2 inhibitors is that cyclooxygenase 1-mediated effects such as blood clotting and gastric secretion are not inhibited, whereas cyclooxygenase 2-mediated effects such as prostaglandin synthesis and thus inflammatory responses are selectively inhibited.

In the skin, cyclooxygenase inhibitors reduce erythema and increased cyclooxygenase levels after UV exposure. Cyclooxygenase 2 inhibitors are used as chemotherapeutic agents to prevent UV-induced skin tumors.

Intolerance reactions frequently occur after systemic administration of nonsteroidal anti-inflammatory drugs and are attributed in particular to inhibition of cyclooxygenase 1 (see analgesic-induced drug intolerance below). Intolerance reactions may range from erythema, urticaria, angioedema, rhinitis, conjunctivitis and photosensitivity to tachycardia, shock and Stevens-Johnson syndrome.