MYCOPHENOLATE SODIUM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MYCOPHENOLATE SODIUM (MYCOPHENOLATE SODIUM).
Mycophenolate sodium is a prodrug that is hydrolyzed to mycophenolic acid (MPA), a reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH). IMPDH is a key enzyme in the de novo synthesis of guanine nucleotides, which is crucial for T- and B-lymphocyte proliferation. MPA preferentially inhibits the type II isoform of IMPDH expressed in activated lymphocytes, thereby exerting immunosuppressive effects.
| Metabolism | Mycophenolate sodium is a prodrug that is rapidly hydrolyzed in the gastrointestinal tract to the active metabolite mycophenolic acid (MPA). MPA is primarily metabolized by uridine diphosphate-glucuronosyltransferase (UGT) 1A9 to the inactive phenolic glucuronide (MPAG). A minor acyl glucuronide metabolite is also formed. MPAG is excreted in the urine and can be deconjugated back to MPA via enterohepatic recirculation. |
| Excretion | Mycophenolate sodium is excreted primarily in urine as mycophenolic acid (MPA) and its glucuronide metabolite (MPAG). Renal excretion accounts for approximately 87% of the dose, with <1% excreted as unchanged MPA. Fecal excretion represents about 6%. |
| Half-life | The terminal elimination half-life of mycophenolic acid is approximately 8-16 hours in healthy subjects and renal transplant patients. The half-life of the inactive glucuronide metabolite (MPAG) is longer (16-18 hours) and accumulates in renal impairment. |
| Protein binding | Mycophenolic acid is 97% bound to serum albumin. The glucuronide metabolite (MPAG) is 82% bound. |
| Volume of Distribution | The apparent volume of distribution of mycophenolic acid is approximately 3.6 L/kg, indicating extensive tissue distribution. This large Vd reflects high tissue binding and distribution into extravascular spaces. |
| Bioavailability | The oral bioavailability of mycophenolate sodium enteric-coated tablets is approximately 72% relative to intravenous mycophenolate mofetil. Food reduces peak concentration (Cmax) by 30-50% but does not significantly affect total area under the curve (AUC). |
| Onset of Action | For oral enteric-coated tablets, peak plasma concentrations are achieved at 1.5-2.5 hours post-dose. The onset of immunosuppressive effect occurs within hours as MPA inhibits inosine monophosphate dehydrogenase (IMPDH), but clinical efficacy in transplant rejection typically requires several days to weeks of continuous therapy. |
| Duration of Action | The pharmacodynamic effect of MPA (IMPDH inhibition) persists for the dosing interval (typically 12 hours). For prevention of transplant rejection, continuous exposure is required; duration of action is not applicable as a single dose. |
| Molecular Weight | 572.56 Da |
720 mg orally twice daily, administered as two 360 mg tablets or two 180 mg capsules. Intravenous infusion: 720 mg intravenously over 2 hours twice daily, for patients unable to tolerate oral therapy.
| Dosage form | TABLET, DELAYED RELEASE |
| Renal impairment | For GFR 15-29 mL/min/1.73 m2: do not exceed 720 mg orally twice daily. For GFR <15 mL/min/1.73 m2: no data; use with caution. No adjustment for GFR >=30 mL/min/1.73 m2. |
| Liver impairment | No specific dose adjustment guidelines for Child-Pugh class A, B, or C. Use with caution in severe hepatic impairment due to limited data. |
| Pediatric use | Approved for pediatric renal transplant patients >=2 years: 400 mg/m2 orally twice daily (up to a maximum of 720 mg twice daily). For bone marrow transplant patients >=2 years: 400 mg/m2 orally twice daily, starting 24 hours after graft infusion. |
| Geriatric use | No specific dose adjustment recommended; elderly patients may have increased risk of adverse effects such as gastrointestinal hemorrhage and infections. Use the lowest effective dose and monitor renal function closely. |
| 1st trimester | Increased risk of congenital malformations, particularly ear anomalies and cleft lip/palate; avoid unless no alternative. |
| 2nd trimester | Risk of miscarriage and structural anomalies continues; use only if benefits outweigh risks. |
| 3rd trimester | Risk of neonatal adverse effects including lymphopenia, anemia, and infections; avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for MYCOPHENOLATE SODIUM (MYCOPHENOLATE SODIUM).
| Placental transfer | Extensive placental transfer; maternal-fetal ratio approximately 0.8-1.0 in animal studies and human data confirm significant fetal exposure. |
| Breastfeeding | Mycophenolate sodium is excreted into breast milk in low concentrations; however, due to potential for serious adverse effects in the nursing infant, breastfeeding is not recommended during therapy. |
■ FDA Black Box Warning
Increased risk of congenital malformations and first-trimester pregnancy loss when used during pregnancy. Females of reproductive potential must be counseled about pregnancy prevention and planning. Mycophenolate can cause fetal harm when administered to a pregnant woman. Use is contraindicated in women of childbearing potential who are not using highly effective contraception.
| Serious Effects |
Pregnancy (unless no alternative and patient counselled)Hypersensitivity to mycophenolate sodium or mycophenolic acidWomen of childbearing potential not using highly effective contraceptionLive vaccines (including BCG, MMR, varicella, yellow fever, oral typhoid, rotavirus)
| Precautions | Immunosuppression: Increased susceptibility to infections, including opportunistic infections and reactivation of latent viruses (e.g., CMV, BK virus)., Lymphoproliferative disorders: Increased risk of post-transplant lymphoproliferative disorder (PTLD) and other malignancies., Pregnancy: Associated with first-trimester pregnancy loss and congenital malformations; contraception counseling required., Gastrointestinal events: Severe GI bleeding, perforation, and ulceration; monitor for symptoms., Neutropenia: Can cause severe neutropenia; monitor complete blood counts regularly., Vaccinations: Live vaccines should not be given during treatment; influenza vaccination may be less effective. |
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| Lactation Rating | L5 - Contraindicated |
| Teratogenic Risk | First trimester: High risk of structural malformations (e.g., cleft lip/palate, microtia, congenital heart defects) and spontaneous abortion. Second and third trimesters: Risk of oligohydramnios, intrauterine growth restriction, and preterm birth. Use is contraindicated in pregnancy unless no alternative. |
| Fetal Monitoring | Monitor immunosuppression parameters (lymphocyte count, immunoglobulins), renal function (serum creatinine, BUN), liver function tests, complete blood count, and signs of infection. Fetal monitoring: serial ultrasounds for growth and anatomy, amniotic fluid volume assessment. |
| Fertility Effects | May impair spermatogenesis in males (reversible) and cause ovarian failure in females; consult fertility specialist. Use effective contraception during therapy and for 6 weeks after discontinuation for females, 90 days for males. |
| Food/Dietary | Take on an empty stomach (1 hour before or 2 hours after meals) to minimize variability. Avoid grapefruit juice (may increase mycophenolate exposure). No specific dietary restrictions other than consistent timing relative to meals. High-fat meals reduce Cmax and AUC; administer consistently with or without food. |
| Clinical Pearls | Monitor CBC weekly during first month, then biweekly for second and third months, then monthly for first year. Consider therapeutic drug monitoring (AUC 30-60 mg·h/L) to optimize dosing and reduce toxicity. Delayed-release formulation (Myfortic) must not be crushed or chewed. Avoid concurrent antacids or bile acid sequestrants. Dose reduction required in renal impairment (eGFR <50 mL/min). Estimate using ideal body weight. Taper when discontinuing to avoid graft rejection. |
| Patient Advice | Take exactly as prescribed; do not stop or change dose without consulting your transplant team. · Swallow delayed-release tablets whole; do not crush, chew, or cut them. · Use reliable contraception before, during, and for 6 weeks after treatment for females; males should use condoms during and for 90 days after treatment. · Avoid live vaccines (e.g., MMR, varicella) and close contact with recently vaccinated individuals. · Report signs of infection (fever, sore throat, chills), unexplained bruising/bleeding, or GI symptoms (nausea, diarrhea, abdominal pain). · Take on an empty stomach (1 hour before or 2 hours after meals) for consistent absorption. · Avoid grapefruit juice as it may alter drug levels. |