All of the following statements about mycophenolate mofetil are true except:
**Core Concept**
Mycophenolate mofetil is an immunosuppressive medication used to prevent rejection in organ transplant patients, particularly those with kidney transplants. It works by inhibiting inosine monophosphate dehydrogenase (IMPDH), an enzyme crucial for the synthesis of guanosine nucleotides, which are essential for lymphocyte proliferation.
**Why the Correct Answer is Right**
Mycophenolate mofetil specifically targets lymphocytes, thereby preventing their proliferation and subsequent activation, which is essential for the immune response. This action is particularly beneficial in preventing acute rejection in transplant patients. The inhibition of IMPDH leads to a decrease in the production of guanosine nucleotides, which are necessary for DNA synthesis and cell division.
**Why Each Wrong Option is Incorrect**
**Option A:** Mycophenolate mofetil is converted to its active metabolite, mycophenolic acid, which is responsible for its immunosuppressive effects. This statement is not necessarily true, as mycophenolate mofetil does have some direct immunosuppressive effects.
**Option B:** Mycophenolate mofetil is used to treat autoimmune diseases such as lupus and rheumatoid arthritis. This statement is incorrect, as mycophenolate mofetil is primarily used as an immunosuppressant in transplant patients, although it may be used off-label in certain autoimmune conditions.
**Option C:** Mycophenolate mofetil can cause gastrointestinal side effects such as diarrhea and nausea. This statement is true, as gastrointestinal side effects are common with mycophenolate mofetil.
**Clinical Pearl / High-Yield Fact**
Mycophenolate mofetil is often used in combination with other immunosuppressive medications, such as cyclosporine and glucocorticoids, to prevent rejection in transplant patients.
**Correct Answer: B. Mycophenolate mofetil is used to treat autoimmune diseases such as lupus and rheumatoid arthritis.**