immunosuppressants

Immunosuppressants are medicines that dampen the immune system. They are used to prevent organ rejection after transplantation and to treat autoimmune and inflammatory diseases. Because they suppress immune function, patients on these drugs have an increased risk of infections and certain cancers and require ongoing monitoring.

Major classes include calcineurin inhibitors (cyclosporine, tacrolimus) that block T-cell activation; antimetabolites (azathioprine, mycophenolate mofetil) that inhibit lymphocyte proliferation; mTOR inhibitors (sirolimus) that retard cell division; corticosteroids (prednisone) with broad anti-inflammatory effects; and biologics (rituximab, abatacept) that target specific immune pathways.

Common indications are prevention of graft rejection after solid organ transplantation and treatment of autoimmune diseases such as rheumatoid arthritis, lupus, inflammatory bowel disease, and some dermatologic disorders. Dosing is individualized and often uses combination regimens to balance efficacy and toxicity.

Adverse effects vary by drug but frequently include infection risk, nephrotoxicity (notably with calcineurin inhibitors), hepatotoxicity, hypertension, dyslipidemia, hyperglycemia, osteoporosis, and cytopenias. Drugs interact with many medicines, and monitoring drug levels, kidney and liver function, and blood counts is essential.

In clinical practice, choice of agent depends on disease, severity, prior response, and safety considerations. Vaccination, infection prevention, and dose adjustments during pregnancy or planning are important considerations.