Mycophenolate Mofetil: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

MMF, CellCept, Mycept, Mofilet

Species with doses

Dogs and Cats

General dose range

10–20 mg/kg PO q12h — check the species tables for the indication

Routes

PO, IV

Last reviewed

1 October 2026

Indications

• Immune-mediated haemolytic anaemia (IMHA) and thrombocytopenia — steroid-sparing
• Immune-mediated polyarthritis, myasthenia gravis, glomerulonephritis
• Immune-mediated/inflammatory skin diseases (e.g. pemphigus) and other immune-mediated disease
• Alternative immunosuppressant when azathioprine is unsuitable (liver disease; cats)

Mycophenolate Mofetil dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Immune-mediated disease (steroid-sparing): Papich 5e: 10 mg/kg PO q8h or 20 mg/kg q8–12h; adverse effects increase with dose. Plumb’s p.870: IMHA, myasthenia gravis, glomerulonephritis 12–17 mg/kg/day once or divided q12h with prednisolone (Nielsen; Macintire); glomerulonephritis 10–20 mg/kg q12h (Labato); pemphigus foliaceus 20–40 mg/kg/day divided q8h (Scott). GI signs (diarrhoea) are dose-limiting.
• Myasthenia gravis rescue (IV): Plumb’s p.870 (Abelson 2009, 3 dogs): 500 mg (15–20 mg/kg) diluted IV over 2–4 h daily until the dog can swallow, then 10–11 mg/kg PO q12h adjusted to response and AChR titres.

Cats

• Immune-mediated disease (limited data): Plumb’s p.870 (Macintire 2009): IMHA 10 mg/kg PO q12h. Papich 5e: no effective cat dose defined — 10 mg/kg q12h is common; doses under 15 mg/kg q12h are tolerated, higher doses cause more GI problems.

Contraindications

Pregnancy (teratogenic). Active serious infection (immunosuppression). Known hypersensitivity. Significant pre-existing GI disease (diarrhoea is dose-limiting). Caution with other immunosuppressants/live vaccines. Handle with care (cytotoxic-class precautions for the formulation).

Species-specific warnings

Cats: Limited feline data, but NOT contraindicated as azathioprine is — use cautiously, monitor CBC and watch for diarrhoea.

Adverse effects

• GI: DIARRHOEA (often large-bowel, dose-limiting), vomiting, anorexia
• Increased infection risk (immunosuppression)
• Bone-marrow suppression (less than azathioprine; monitor)
• Rare: lymphoma/other neoplasia with long-term immunosuppression

Drug interactions

• Antacids / bile-acid sequestrants / oral iron: reduce mycophenolate absorption — separate dosing
• Other immunosuppressants: additive immunosuppression (often intentional, e.g. with steroids/ciclosporin)
• Live vaccines: avoid
• Drugs altering enterohepatic recirculation (some antibiotics): can lower levels

Pregnancy and lactation

Contraindicated in pregnancy — teratogenic (congenital malformations, pregnancy loss).

Monitoring

• Clinical/disease response (e.g. rising PCV/platelets in IMHA/ITP) over 1–3 weeks
• GI tolerance — DIARRHOEA is the usual dose-limiter (reduce dose)
• CBC (marrow suppression) periodically; infection surveillance
• Taper concurrent glucocorticoids as control is achieved

Toxicity and overdose

The dose-limiting toxicity is GI — particularly large-bowel DIARRHOEA — which usually responds to dose reduction. Immunosuppression brings infection risk; bone-marrow suppression occurs but is generally milder than with azathioprine; long-term immunosuppression carries a theoretical neoplasia risk. It is NOT hepatotoxic (a key advantage over azathioprine).

Management: No specific antidote. Discontinue/reduce dose; supportive care for diarrhoea (fluids, dietary management) and any neutropenia (monitor CBC, treat infections). Bile-acid sequestrants (cholestyramine) can reduce mycophenolate levels by interrupting enterohepatic recirculation. Manage infections vigorously.

Clinical pearls

• A faster-acting, NON-hepatotoxic steroid-sparing immunosuppressant — a good azathioprine alternative, especially with liver disease, and (unlike azathioprine) not contraindicated in cats
• DIARRHOEA (often large-bowel) is the dose-limiter — reduce the dose rather than stopping if it occurs
• Selective lymphocyte suppression (IMPDH inhibition) gives less marrow toxicity than azathioprine and no hepatotoxicity
• Combine with glucocorticoids for immune-mediated disease and taper steroids as remission is achieved; avoid in pregnancy (teratogen) and handle with gloves

Mechanism of action

Mycophenolate mofetil is a pro-drug hydrolysed to mycophenolic acid, which reversibly and selectively inhibits inosine monophosphate dehydrogenase (IMPDH) — the rate-limiting enzyme of de-novo GUANOSINE (purine) synthesis. Lymphocytes depend almost exclusively on this de-novo pathway (lacking a salvage route), so their proliferation (both T and B cells, and antibody production) is preferentially suppressed — producing targeted immunosuppression with relatively little effect on other rapidly dividing tissues (hence less marrow toxicity than azathioprine and no hepatotoxicity).

Formulations and products

• 250 mg capsule / 500 mg tablet
• Oral suspension 200 mg/mL
• IV infusion 500 mg vial
• CellCept — 250 mg capsule / 500 mg tablet; 200 mg/mL suspension, Capsule / tablet / suspension (human-label)
• Mycept / Mofilet — 250 / 500 mg, Capsule / tablet (human-label)

Storage

Capsules/tablets/suspension: 15–30 °C, dry, protect from light; handle with gloves (teratogenic/cytotoxic-class), do not crush. Suspension per label.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other hormones, emergency drugs, supplements and other drugs

• Methocarbamol
• Methylcobalamin (Active B12)
• Methylene Blue
• Mitotane (o,p'-DDD)
• N-Acetylcysteine (NAC)
• Naloxone HCl
• Nandrolone Decanoate
• Neostigmine

Frequently asked questions