Inosine monophosphate dehydrogenase inhibitor Pregnancy: Contraindicated during pregnancy unless there is no suitable alternative treatment to prevent transplant rejection, and contraindicated in breastfeeding. Mycophenolate is a powerful human teratogen — spontaneous abortions have been reported in 45 to 49% of exposed pregnancies (versus 12 to 33% in solid organ transplant patients on other immunosuppressants) and malformations in 23 to 27% of live births (versus 2 to 3% in the overall population). Women of childbearing potential must use at least one form of reliable contraception (two complementary forms simultaneously are preferred) before starting therapy, during therapy, and for six weeks after stopping, unless abstinence is chosen. Before starting, women of childbearing potential should have two negative serum or urine pregnancy tests with a sensitivity of at least 25 mIU/mL, the second performed 8 to 10 days after the first; where the timing of a deceased-donor transplant makes this impossible, a test must be performed immediately before starting treatment and a further test 8 to 10 days later. Pregnancy tests should be repeated as clinically required.

Mycophenolate mofetil

Brand names: CellCept, Myfortic (mycophenolic acid)

Mycophenolate mofetil is an oral immunosuppressant used to prevent transplant rejection and, off-licence, as a steroid-sparing agent in autoimmune and connective-tissue diseases.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Renal transplant: 1 g twice daily (2 g total daily dose), i.e. 5 mL of the 1 g/5 mL oral suspension twice daily. DOSE IS INDICATION-SPECIFIC — cardiac transplant and hepatic transplant: 1.5 g twice daily (3 g total daily dose).

Route: Oral administration. The 1 g/5 mL oral suspension may if required be given via a nasogastric tube with a minimum size of 8 French (minimum 1.7 mm interior diameter); shake well before use. Avoid direct contact of the suspension with the skin — if contact occurs, wash thoroughly with soap and water and rinse eyes with plain water.

Frequency: Twice daily

SOURCE: UK SPC (Mycophenolate Mofetil 1g/5ml oral suspension, https://www.medicines.org.uk/emc/product/15056/smpc), section 4.2. Treatment should be initiated and maintained by appropriately qualified transplant specialists. TIMING OF INITIATION: renal transplant — oral mycophenolate mofetil should be initiated within 72 hours following transplantation. Cardiac transplant — within 5 days following transplantation. Hepatic transplant — INTRAVENOUS mycophenolate mofetil should be administered for the first 4 days following hepatic transplant, with oral mycophenolate mofetil initiated as soon after this as it can be tolerated; the recommended ORAL dose in hepatic transplant patients is 1.5 g twice daily. NOTE: this SPC is for the ORAL SUSPENSION — the intravenous dose for the first 4 days after hepatic transplant is NOT given in this source and must be obtained from the intravenous product SPC. ELDERLY: the recommended dose of 1 g twice a day for renal transplant patients and 1.5 g twice a day for cardiac or hepatic transplant patients is appropriate for the elderly. SEVERE HEPATIC IMPAIRMENT: no dose adjustments are needed for renal transplant patients with severe hepatic parenchymal disease; no data are available for cardiac transplant patients with severe hepatic parenchymal disease. TREATMENT DURING REJECTION EPISODES: renal transplant rejection does not lead to changes in mycophenolic acid pharmacokinetics, so dosage reduction or interruption is not required; there is no basis for dose adjustment following cardiac transplant rejection; no pharmacokinetic data are available during hepatic transplant rejection. PAEDIATRIC (1 to 18 years) — NOT structured in paedDose because the SPC dose is body-surface-area based (mg/m2), not per kg: 'The recommended mycophenolate mofetil initial dose for paediatric renal, cardiac and hepatic transplant patients is 600 mg/m2 (of body surface area (BSA)) administered orally, twice daily (initial total daily dose not to exceed 2 g, or 10 ml of the oral suspension).' If the recommended initial dose is well tolerated but does not achieve clinically adequate immunosuppression in paediatric CARDIAC and HEPATIC transplant patients, the dose can be increased to 900 mg/m2 BSA twice daily (maximum total daily dose of 3 g, or 15 ml of the oral suspension). The recommended maintenance dose for paediatric RENAL transplant patients remains 600 mg/m2 twice daily (maximum total daily dose of 2 g or 10 ml). The powder for oral suspension should be used in patients unable to swallow capsules and tablets and/or with a BSA lower than 1.25 m2, because of the increased risk of choking. Patients with a BSA of 1.25 to 1.5 m2 may be prescribed capsules at 750 mg twice daily (1.5 g daily); patients with a BSA greater than 1.5 m2 may be prescribed capsules or tablets at 1 g twice daily (2 g daily). Because some adverse reactions occur with greater frequency in this age group compared with adults, temporary dose reduction or interruption may be required. Different oral formulations should not be substituted without clinical supervision, and the dose and product form should be individualised based on clinical assessment. No data are available for treatment of first or refractory rejection in paediatric transplant patients. The SPC's dose-to-volume conversion table (600 mg/m2 and 900 mg/m2 levels, BSA by the Mosteller formula, oral dispenser graduated in 0.25 mL increments corresponding to 50 mg) should be used for suspension dosing. Verify any under-18 use against a children's formulary. SPC sections 4.4, 4.6 and 4.8 were truncated at the source-fetch limit.

Dose adjustments

Renal

In renal transplant patients with severe chronic renal impairment (glomerular filtration rate below 25 mL/min/1.73 m2), outside the immediate post-transplant period, doses greater than 1 g administered twice a day should be avoided, and these patients should be carefully observed. No dose adjustments are needed in patients experiencing delayed renal graft function post-operatively. No data are available for cardiac or hepatic transplant patients with severe chronic renal impairment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to mycophenolate mofetil, mycophenolic acid or to any of the excipients
Women of childbearing potential who are not using highly effective contraception
Treatment must not be initiated in women of childbearing potential without providing a pregnancy test result to rule out unintended use in pregnancy
Pregnancy — unless there is no suitable alternative treatment to prevent transplant rejection
Women who are breastfeeding

Side effects

Diarrhoea (up to 52.6%) — among the most common and/or serious reactions with mycophenolate mofetil in combination with ciclosporin and corticosteroids
Leucopenia (up to 45.8%) — very common in renal, hepatic and cardiac transplant patients; anaemia also very common, with thrombocytopenia, pancytopenia and (uncommonly) pure red cell aplasia and bone marrow failure
Bacterial infections (up to 39.9%) and viral infections — very common in all three transplant indications; fungal and protozoal infections also reported, including latent viral reactivation (hepatitis B or C) and polyomavirus disease (BK virus nephropathy, JC virus PML)
Vomiting (up to 39.1%) — among the most common reactions
Malignancy — increased risk of lymphomas and other malignancies, particularly of the skin (benign neoplasm of skin and skin cancer common; lymphoma and lymphoproliferative disorder uncommon)
Metabolic and electrolyte disturbance — hypercholesterolaemia and hypophosphataemia very common in renal transplant, with hyperglycaemia, hyperkalaemia, hypokalaemia, hypomagnesaemia, hypocalcaemia, hyperuricaemia and acidosis reported across indications
Also reported in section 4.4: hypogammaglobulinaemia with recurrent infections, bronchiectasis, and isolated reports of interstitial lung disease and pulmonary fibrosis, some fatal

Interactions

NOTE ON SOURCE: UK SPC section 4.5 was NOT fetched in this bundle. The entries below are from the US label (mycophenolate mofetil, section 7) and must be checked against UK SPC section 4.5.
Antacids containing magnesium or aluminium hydroxide — decrease mycophenolic acid systemic exposure, which may reduce efficacy. Administer such antacids at least 2 hours after mycophenolate mofetil.
Proton pump inhibitors (e.g. lansoprazole) — decrease mycophenolic acid systemic exposure, which may reduce efficacy. Monitor for alterations in efficacy.
Drugs that interfere with enterohepatic recirculation, telmisartan and calcium-free phosphate binders — listed by the US label as interfering with systemic exposure and reducing efficacy.
Oral contraceptives — mycophenolate mofetil may reduce their effectiveness; additional barrier contraceptive methods are recommended.
Live attenuated vaccines — the US label's warnings section states these should be avoided.

Clinical monograph

How it works

It is a prodrug of mycophenolic acid, which reversibly inhibits inosine monophosphate dehydrogenase and thereby suppresses purine synthesis in proliferating T and B lymphocytes.

Prescribing in practice

It is teratogenic with a high risk of miscarriage and congenital malformation, so pregnancy must be excluded and effective contraception used by people of childbearing potential in line with the MHRA pregnancy-prevention requirements.
It increases susceptibility to serious infection and is associated with bone marrow suppression and a small increased long-term risk of malignancy including skin cancer.
Gastrointestinal upset is common and the enteric-coated mycophenolate sodium form is not directly milligram-equivalent, so do not switch formulations without dose adjustment.

Monitoring

Monitor full blood count regularly, especially in the early months, alongside vigilance for infection and skin changes.

Counselling the patient

Use reliable contraception and never take it in pregnancy unless specialist-advised.
Report sore throat, fever, bruising or signs of infection promptly.
Use sun protection and report new skin lesions.

Evidence & guidelines

Mycophenolate mofetil is well established in transplantation and widely used as an immunosuppressant in autoimmune disease, supported by specialist guidance and MHRA safety advice.

Reference: NICE; MHRA Drug Safety Update; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways