What is being tested?
This test measures the amount of mycophenylate or mycophenolic acid (MPA) in the blood. Mycophenolic acid is the active metabolite of mycophenolate, a drug that is primarily given to patients who have had a heart, kidney or liver transplant. There are two formulations of the drug available, mycophenolate mofetil and mycophenolate sodium.
Mycophenylate belongs to a group of immunosuppressant drugs which helps to prevent organ rejection. Normally, a person’s immune system would recognise a transplanted organ as foreign and begin to attack it. Mycophenylate limits this response by preventing the activation of the immune system cells known as T-lymphocyte and B-lymphocytes.
Like other immunosuppressant agents, mycophenylate may cause side effects and adverse reactions and is associated with an increased risk of infection and the development of lymphoma and other cancerous conditions, especially skin cancers.
Mycophenolate is given to organ transplant patients in conjunction with other immunosuppressant drugs, such as cyclosporin and tacrolimus.
The mmycophenylate blood test is usually measured as a “trough” level, that is, the blood sample is taken just before the next dose of the medicine is due, when the drug is at its lowest concentration in the blood.
How is it used?
The mycophenylate test is ordered to measure the level of drug in the blood. This test has not always been done routinely in people taking mycophenylate. Instead, doctors give a standard dose of mycophenylate and monitor the drug level indirectly by observing the effects on the patient. However, the physician may also wish to monitor the drug level directly by measuring the level of mycophenylate in the blood. For example, they may be concerned that the standard dose may be too high or too low because the mycophenylate level may be affected by another medicine the person is taking.
If someone is taking mycophenolate in addition to cyclosporin or tacrolimus, then both MPA and the other immunosuppressant concentrations will be measured.
Since mycophenylate can lower white blood cell counts and cause anaemia, a full blood count (FBC) will frequently be ordered along with the mycophenylate test to evaluate the body’s blood cell status. Other tests may also be periodically ordered to evaluate organ function as mycophenylate levels can be affected by changes in kidney and liver function.
When is it requested?
Mycophenylate and FBC are ordered frequently at the start of therapy and then at intervals for as long as the patient is taking mycophenolate. The mmycophenylate test may be performed whenever there is a change in dosage, a change in other medications that the patient is taking, or whenever a patient has symptoms that suggest side effects, toxicity or organ rejection.
What does the result mean?
Concentrations that are too high may cause toxicity. Concentrations that are too low may lead to rejection of the transplanted organ.
If the person is also taking another immunosuppressant and/or other medications, then all of them will need to be in balance. Patients should work closely with their doctor and transplant team and report any adverse effects to their GP and/or specialist.
Is there anything else I should know?
Mycophenylate levels can be affected by other medications. Drugs that reduce mycophenylate concentrations include antacids and cholestyramine. Drugs that can increase mycophenylate include ganciclovir, probenecid, and acyclovir. Herbal supplements may interact with mycophenylate.
Mycophenylate can decrease the effectiveness of oral contraceptives, and has been linked with first trimester miscarriages and congenital birth defects. Women should not become pregnant while taking mycophenolate and should not breastfeed. Two forms of birth control are recommended, as is a pregnancy test prior to the start of the medication. Patients who become pregnant should talk to their doctor about the associated risks.
Those who are taking mmycophenylate should talk to their doctor before getting any vaccines.
Patients may have side effects and experience complications such as infections and slow healing even when taking mycophenylate properly. Side effects may include:
Common questions
After transplantation, you must take an immunosuppressant (or a combination of immunosuppressants) for the rest of your life. Thus, in this situation, mycophenylate is usually given long-term.
Mycophenylate tests may be performed in a local hospital laboratory but will frequently be sent to a specialist reference laboratory. Because different laboratories use different testing methods, their results may be slightly different. However, your doctor will usually send your tests consistently to one laboratory for testing to avoid confusion.
Yes, this is important information for them, partially because of drug interactions and partially because of the immunosuppressant action of mycophenylate. It can affect your ability to heal, to get vaccinations, and may increase the risk of developing certain cancers (such as skin cancers and lymphoma). People who take mycophenylate should avoid exposure to sunlight and wear protective clothing and sunscreen (SPF 30 or higher) when they are outdoors.
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