Mykofenolan

Mykofenolan, typically encountered as mycophenolate mofetil (MMF) or mycophenolate sodium, is an immunosuppressive medication used to prevent organ transplant rejection and to treat certain autoimmune diseases. It is a prodrug that is converted in the body to mycophenolic acid (MPA), the active component.

Mechanism of action: MPA inhibits inosine monophosphate dehydrogenase (IMPDH), the rate‑limiting enzyme in de novo guanine nucleotide synthesis. Lymphocytes rely heavily on this pathway, so mycophenolate selectively reduces the proliferation of activated T and B cells, dampening immune responses.

Medical uses: MMF is widely used for prophylaxis of kidney, heart, and liver transplant rejection, usually in combination with calcineurin inhibitors and corticosteroids. In autoimmune disease, it is employed for systemic lupus erythematosus with nephritis and other refractory conditions. It is also used in hematopoietic stem cell transplantation settings for graft-versus-host disease prophylaxis or treatment in some protocols.

Pharmacokinetics and administration: MMF is rapidly absorbed and converted to MPA. Its activity is influenced by enterohepatic recirculation and food intake. Metabolism occurs in the liver with renal and fecal excretion of metabolites. Dosing is tailored to the indication and in many regimens combined with another immunosuppressant; therapeutic drug monitoring may be used in specific settings.

Side effects and safety: Common adverse effects include gastrointestinal symptoms (nausea, diarrhea, vomiting), leukopenia, anemia, and increased infection risk. Hypertension, edema, and increased susceptibility to certain cancers may occur with long-term use. Pregnancy is contraindicated due to teratogenic risk; effective contraception is advised during treatment and exposure should be avoided in lactation.

Interactions and precautions: Concomitant calcineurin inhibitors can affect MPA exposure and toxicity. Antacids or bile acid sequestrants and cholestyramine can alter absorption. Vaccination with live vaccines is generally not recommended during therapy. Renal and hepatic function should be monitored, and use requires careful consideration of infection risk and reproductive counseling.