MYFORTIC
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MYFORTIC (MYFORTIC).
Mycophenolic acid inhibits inosine monophosphate dehydrogenase (IMPDH), thereby depleting guanosine nucleotides in T and B lymphocytes, suppressing their proliferation and antibody production.
| Metabolism | Mycophenolic acid is primarily metabolized by glucuronidation via UDP-glucuronosyltransferases (UGT1A9, UGT2B7) to its inactive glucuronide metabolite (MPAG). Minimal CYP450 metabolism. |
| Excretion | Primarily renal (approximately 95% as metabolites, <3% as unchanged drug); biliary/fecal excretion accounts for <5%. |
| Half-life | Terminal elimination half-life is approximately 12-18 hours (mean 17 hours) in healthy volunteers; longer in hepatic impairment (up to 40 hours). |
| Protein binding | Approximately 97% bound to serum albumin. |
| Volume of Distribution | Volume of distribution is approximately 1.1 L/kg (range 0.8-1.5 L/kg), indicating extensive tissue distribution. |
| Bioavailability | Oral bioavailability is approximately 20% (range 15-30%) due to first-pass metabolism; absorption is unaffected by food. |
| Onset of Action | Oral: Peak immunosuppression occurs within 1-2 hours after dosing; clinical effect (e.g., prevention of rejection) is typically observed within days to weeks. |
| Duration of Action | Immunosuppressive effect persists for the dosing interval (every 12 hours); trough levels correlate with efficacy and toxicity. |
| Molecular Weight | 433.5 |
| Action Class | Immunosuppressant- Purine analogs |
| Brand Substitutes | MY 360 Tablet, Mycept-S 360 Tablet, MMF -S Tablet, Mycosan S 360mg Tablet, Biomyf-S 360 Tablet, Mycoral 180mg Tablet, Mycept-S 180 Tablet, Renfor 180mg Tablet, Picept 180mg Tablet, Mofilet S 180 Tablet |
720 mg orally twice daily, on an empty stomach, 1 hour before or 2 hours after meals.
| Dosage form | TABLET, DELAYED RELEASE |
| Renal impairment | For GFR 30-59 mL/min: maximum 1440 mg/day. For GFR <30 mL/min: not recommended. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose to 720 mg twice daily. Child-Pugh C: avoid use. |
| Pediatric use | For patients ≥5 years: 400 mg/m² orally twice daily, maximum 720 mg twice daily. |
| Geriatric use | No specific adjustment, but monitor renal function and consider lower end of dosing range due to age-related decline in GFR. |
| 1st trimester | Avoid unless benefit outweighs risk. Mycophenolate mofetil is teratogenic in humans, associated with increased risk of first trimester pregnancy loss and congenital malformations (e.g., cleft lip/palate, ear abnormalities). |
| 2nd trimester | Avoid unless benefit outweighs risk. Continued risk of teratogenicity and fetal toxicity. May cause fetal renal impairment and low birth weight. |
| 3rd trimester | Avoid unless benefit outweighs risk. Potential for neonatal immunosuppression and hematologic abnormalities. Should not be used during pregnancy unless no alternative. |
Clinical note
Comprehensive clinical and safety monograph for MYFORTIC (MYFORTIC).
| Placental transfer | Mycophenolate mofetil and its active metabolite mycophenolic acid cross the placenta. Fetal exposure is significant, with maternal-fetal transfer confirmed in ex vivo human placental models. Plasma levels in cord blood are approximately equivalent to maternal levels. |
| Breastfeeding |
■ FDA Black Box Warning
Increased risk of congenital malformations and spontaneous abortion when used during pregnancy. Females of reproductive potential must be counseled and use effective contraception.
| Serious Effects |
Hypersensitivity to mycophenolate mofetil, mycophenolic acid, or any component of the formulationWomen of childbearing potential not using highly effective contraception (unless patient has confirmed negative pregnancy test and no possibility of pregnancy)Pregnancy (unless no alternative and patient is fully informed of risks)
| Precautions | Increased risk of lymphomas and other malignancies, particularly skin cancer. Increased susceptibility to infections (bacterial, viral, fungal, protozoal). Severe neutropenia, pure red cell aplasia. Gastrointestinal hemorrhage, perforation. Nephrotoxicity when coadministered with cyclosporine. Avoid concomitant use with azathioprine. |
| Food/Dietary | Take on an empty stomach at consistent times relative to meals. Avoid grapefruit juice. High-fat meals may reduce peak concentrations but not overall exposure; however, to minimize variability, administer without food. Antacids containing magnesium or aluminum should be separated by at least 2 hours. |
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| Mycophenolate mofetil is excreted into breast milk in low amounts but may cause immunosuppression and neutropenia in the nursing infant. Manufacturer recommends discontinuing breastfeeding due to potential for serious adverse reactions. Alternative agents may be preferred if breastfeeding is desired. |
| Lactation Rating | L4 - Possibly Hazardous |
| Teratogenic Risk | Myfortic (mycophenolic acid) is contraindicated in pregnancy due to high risk of first trimester pregnancy loss and congenital malformations (including ear, facial, and cardiac defects) with exposures during organogenesis. Second and third trimester exposure may increase risk of preterm delivery and low birth weight. A pregnancy test must be obtained prior to initiation and repeated during therapy. |
| Fetal Monitoring | Monitor for neutropenia, anemia, and thrombocytopenia via complete blood count weekly for first month, biweekly for months 2-3, then monthly. Monitor renal function and hepatic enzymes. Pregnancy test before start, then at follow-up intervals. Monitor for infections and malignancies. Assess fetal development with ultrasound if pregnancy occurs. |
| Fertility Effects | In males, mycophenolic acid may impair spermatogenesis and reduce sperm count and motility based on animal studies; reversible upon discontinuation. In females, no direct fertility impairment reported, but risk of pregnancy loss is high. Effective contraception must be used during therapy and for 6 weeks after cessation. |
| Clinical Pearls | Myfortic (mycophenolate sodium) is an enteric-coated formulation of mycophenolic acid (MPA) designed to reduce upper GI adverse effects. Monitor for leukopenia, anemia, and thrombocytopenia; dose adjustments may be needed. Avoid concomitant use with azathioprine due to additive myelosuppression. Measure MPA levels in cases of graft dysfunction or suspected toxicity. |
| Patient Advice | Take Myfortic on an empty stomach (1 hour before or 2 hours after food) to ensure consistent absorption. · Swallow tablets whole; do not crush, chew, or cut them as the enteric coating protects the stomach. · Avoid grapefruit and grapefruit juice as they may alter drug levels. · Report any signs of infection (fever, sore throat, unexplained bruising or bleeding) immediately. · Use effective contraception during treatment and for 6 weeks after stopping due to risk of fetal harm. · Do not take antacids or iron supplements within 2 hours of Myfortic as they reduce absorption. |