Hard Contraindications for Mycophenolate
The only absolute contraindication to mycophenolate mofetil is hypersensitivity to mycophenolate mofetil, mycophenolic acid, or any component of the drug product 1. However, pregnancy represents a critical clinical contraindication with a black box warning, and the drug must be discontinued at least 6-12 weeks before conception 2, 3.
Absolute Contraindications
Hypersensitivity Reactions
- Documented allergic reactions to mycophenolate mofetil, mycophenolic acid, or any drug component 1
- This is the only FDA-listed absolute contraindication
Critical Clinical Contraindications (Black Box Warnings)
Pregnancy - Category D
Mycophenolate is absolutely contraindicated in pregnancy due to severe teratogenic effects 2, 3, 4:
- Miscarriage rate: 49%
- Stillbirth rate: 2%
- Structural anomaly rate: 23% 2
Specific malformations documented include:
- Hypoplastic nails and shortened fifth fingers
- Microtia (absent or malformed ears)
- Absence of auditory canals
- Cleft lip and palate abnormalities
- Tetralogy of Fallot
- Total anomalous pulmonary venous return 2
Required washout period: 6-12 weeks (some guidelines specify 12 weeks minimum) before attempting conception 2, 3
Contraception requirements: Patients must use two reliable forms of contraception while on mycophenolate 5, 6
Lactation
Mycophenolate should not be used during breastfeeding 4, 6, 4
Important Clinical Caveats
Not Absolute Contraindications But Require Extreme Caution:
Severe infections: While not an absolute contraindication, active severe infections warrant careful risk-benefit assessment given the immunosuppressive effects 7
Concurrent azathioprine use: Should be avoided due to increased inhibition of purine metabolism 7, though this represents a drug interaction rather than an absolute contraindication
TPMT deficiency: In patients homozygous for TPMT deficiency who cannot take azathioprine, mycophenolate can actually be substituted (with pregnancy precautions) 5, so this is not a contraindication to mycophenolate itself
Common Pitfalls to Avoid:
- Do not confuse relative contraindications with absolute ones: Renal impairment, cytopenias, and GI disease require dose adjustment and monitoring but are not absolute contraindications
- Do not overlook the pregnancy washout period: Simply stopping at conception is insufficient—require 6-12 weeks minimum 2, 3
- Do not forget contraception counseling: This must occur before initiating therapy in all women of childbearing potential 5, 3