Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ASTAGRAF XL vs ENVARSUS XR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Calcineurin inhibitor that binds to FKBP-12, forming a complex that inhibits calcineurin, thereby preventing dephosphorylation and nuclear translocation of NFAT, which reduces T-cell activation and cytokine production (e.g., IL-2).
Calcineurin inhibitor. Binds to FKBP-12, forming a complex that inhibits calcineurin phosphatase, thereby blocking T-cell activation and IL-2 transcription.
Prophylaxis of organ rejection in kidney transplant recipients,Prophylaxis of organ rejection in liver transplant recipients,Prophylaxis of organ rejection in heart transplant recipients
Prophylaxis of organ rejection in kidney transplant patients,Prophylaxis of organ rejection in liver transplant patients
Initial oral dose of 0.1-0.15 mg/kg/day divided every 12 hours, with subsequent adjustments based on trough levels. Typical maintenance dose 0.05-0.15 mg/kg/day.
0.2 mg/kg/day orally once daily, with the morning meal, using extended-release tablets. Dose adjustments guided by trough concentrations.
Terminal elimination half-life is approximately 43 hours (range 15.8–68.6 hours) in adult kidney transplant recipients. This long half-life supports once-daily dosing. In liver transplant patients, half-life ranges from 12 to 42 hours.
Terminal half-life approximately 25-30 hours in stable renal transplant patients. Longer half-life (up to 50 hours) in patients with hepatic impairment.
Primarily hepatic via CYP3A4 and CYP3A5; undergoes extensive first-pass metabolism. Substrate of P-glycoprotein.
Primarily hepatic via CYP3A4 and CYP3A5; also metabolized by intestinal CYP3A4.
Primarily fecal (94.6%) via biliary elimination. Renal excretion accounts for approximately 2.4% of the dose, mainly as metabolites. Less than 1% is excreted unchanged in urine.
Primarily fecal (94%) with minor renal excretion (2.2% as unchanged drug). Biliary excretion is a significant route.
Approximately 99% bound to plasma proteins, primarily albumin and alpha-1-acid glycoprotein.
Approximately 99% bound to erythrocytes and plasma proteins, primarily albumin and alpha-1-acid glycoprotein.
Volume of distribution is 3.5–4.5 L/kg (wide distribution, indicating extensive tissue binding). High Vd reflects distribution into erythrocytes, lymphocytes, and tissues.
0.9-1.4 L/kg in renal transplant patients; large volume indicates extensive tissue distribution, particularly to red blood cells.
Oral bioavailability is highly variable, approximately 20–30% (range 5–89%). Absorption is incomplete and inconsistent; food decreases absorption by up to 33%. The modified-release formulation (Astagraf XL) has a lower peak and more sustained absorption compared to immediate-release.
Oral bioavailability is approximately 15-25% with the extended-release formulation; reduced by high-fat meal, so should be taken consistently on an empty stomach.
For GFR <30 m L/min: reduce dose by 50% and monitor trough levels closely. No adjustment for GFR >30 m L/min.
No specific GFR-based dose adjustment; however, due to nephrotoxicity, monitor renal function closely and reduce dose if renal impairment occurs. For patients with severe renal impairment (Cr Cl <30 m L/min), consider alternative immunosuppression.
Child-Pugh Class A: no adjustment. Class B: reduce dose by 25%. Class C: reduce dose by 50% and monitor trough levels frequently.
In patients with mild to moderate hepatic impairment (Child-Pugh A or B), reduce dose by 25%. For severe hepatic impairment (Child-Pugh C), reduce dose by 50% and monitor trough levels closely.
Initial oral dose 0.15-0.2 mg/kg/day divided every 12 hours. Adjust to target trough levels of 5-15 ng/m L. Maximum dose 0.3 mg/kg/day.
For pediatric kidney transplant recipients: 0.2 mg/kg/day orally once daily, with morning meal. Adjust to target trough concentrations. Safety and efficacy not established for other indications in pediatrics.
Start at lower end of adult dosing range (0.05 mg/kg/day) and titrate slowly due to reduced renal function and increased risk of adverse effects. Monitor trough levels closely.
No specific dose adjustment; however, elderly patients may have increased susceptibility to nephrotoxicity and neurotoxicity. Use lowest effective dose, monitor renal function, and adjust based on trough levels.
Increased susceptibility to infection and possible development of lymphoma and other malignancies, particularly of the skin, due to immunosuppression. Increased nephrotoxicity, especially when used with other nephrotoxic drugs.
Increased susceptibility to infection and possible development of malignancy (e.g., lymphoma, skin cancer).
Nephrotoxicity, neurotoxicity (tremor, headache, seizures), hypertension, hyperkalemia, hyperglycemia, increased risk of infections and malignancies (especially skin), and lymphoproliferative disorders. Monitor blood pressure, renal function, electrolytes, and drug levels.
Nephrotoxicity, neurotoxicity, hypertension, hyperkalemia, post-transplant diabetes mellitus, monitoring of blood concentrations required.
Hypersensitivity to tacrolimus or any component of the formulation; concurrent use with cyclosporine or other calcineurin inhibitors.
Hypersensitivity to tacrolimus or any component of the formulation.
Grapefruit juice significantly increases tacrolimus AUC and Cmax; avoid concurrent use. High-fat meals may decrease absorption; maintain consistent fat intake with each dose to ensure stable levels. Avoid taking with alcohol or herbal supplements like St. John's wort, which may reduce efficacy.
Grapefruit and grapefruit juice increase tacrolimus exposure and must be avoided. High-fat meals may decrease absorption; consistency of food intake relative to dosing is recommended. Alcohol should be limited due to potential additive hepatotoxicity.
Tacrolimus is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, tacrolimus caused maternal toxicity and embryotoxicity at doses higher than those used clinically. First trimester exposure is associated with an increased risk of congenital anomalies, including cardiac malformations. Second and third trimester use has been linked with intrauterine growth restriction, preterm delivery, and transient neonatal hyperkalemia and renal dysfunction. Postnatal immunosuppression in the neonate may occur.
Envarsus XR (tacrolimus) is classified as FDA Pregnancy Category C. In the first trimester, there is an increased risk of congenital anomalies (e.g., cardiac, renal) based on animal studies; human data are limited but suggest a possible small increase. During the second and third trimesters, risks include intrauterine growth restriction, preterm delivery, and transient neonatal hyperkalemia and renal dysfunction. Advise women of childbearing potential to use effective contraception.
Tacrolimus is excreted into human breast milk with a milk-to-plasma (M/P) ratio of approximately 0.3. Limited data suggest low infant exposure (relative infant dose 0.5% of maternal weight-adjusted dose). However, because of potential for infant immunosuppression and growth effects, breastfeeding is generally not recommended unless benefits outweigh risks. Monitor infant for trough levels if breastfeeding.
Tacrolimus is excreted into human breast milk. The milk-to-plasma ratio is approximately 0.5 (range 0.12–0.75). Infant exposure is estimated to be <1% of the maternal weight-adjusted dose, which is considered low. However, due to potential for immunosuppression and adverse effects, breastfeeding is generally not recommended unless benefits outweigh risks. Monitor infant for signs of immunosuppression.
Pregnancy increases tacrolimus clearance due to expanded plasma volume and altered cytochrome P450 3A4 activity. Dose requirements may increase by 25-50% during the second and third trimesters. Therapeutic drug monitoring is essential, targeting trough levels 5-10 ng/m L. Postpartum, doses should be reduced to prepregnancy levels within 1-2 weeks as clearance normalizes.
Pregnancy induces pharmacokinetic changes including increased volume of distribution, altered protein binding, and enhanced clearance of tacrolimus. Frequent monitoring of trough concentrations is essential to maintain therapeutic levels (target 5–10 ng/m L). Dose adjustments (increases of 20–50% or more) are often required, especially during the second and third trimesters. Postpartum, doses should be reduced to pre-pregnancy levels within 1–2 weeks.
Monitor trough levels 5-15 ng/m L; avoid using with sirolimus due to increased risk of thrombotic microangiopathy; conversion from tacrolimus immediate-release is 1:1 (mg:mg) but monitor levels closely for 2 weeks; administer consistently with or without food to avoid fluctuations.
ENVARSUS XR is an extended-release formulation of tacrolimus; conversion from immediate-release tacrolimus requires close therapeutic drug monitoring due to altered pharmacokinetics. Administer consistently with or without food to minimize variability. Avoid grapefruit products. Monitor renal function, blood pressure, electrolytes, glucose, and trough tacrolimus levels. CYP3A4/5 inducers/inhibitors significantly affect tacrolimus exposure; adjust dose accordingly. Do not crush, chew, or split tablets.
Take at the same time every day, consistently with or without food.,Do not crush, chew, or split the extended-release capsules; swallow whole.,Avoid grapefruit and grapefruit juice as they can increase drug levels and toxicity.,Report signs of infection (fever, sore throat), tremors, or changes in urine output immediately.,Minimize sun exposure and use sunscreen due to increased risk of skin cancer.,Do not change brand or formulation without consulting your transplant team.,Keep all appointments for blood level monitoring.
Take exactly as prescribed, at the same time each day, with or without food but consistently.,Swallow whole; do not crush, chew, or break the tablet.,Avoid grapefruit and grapefruit juice.,Do not stop or change dose without consulting your doctor.,Report signs of infection (fever, sore throat), tremor, headache, changes in urination, or unusual bleeding.,Avoid live vaccines and limit sun exposure due to increased skin cancer risk.,Keep all appointments for blood tests to monitor drug levels and organ function.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ASTAGRAF XL vs ENVARSUS XR, answered by our medical review team.
ASTAGRAF XL is a Immunosuppressant, Calcineurin Inhibitor that works by Calcineurin inhibitor that binds to FKBP-12, forming a complex that inhibits calcineurin, thereby preventing dephosphorylation and nuclear translocation of NFAT, which reduces T-cell activation and cytokine production (e.g., IL-2).. ENVARSUS XR is a Calcineurin Inhibitor Immunosuppressant that works by Calcineurin inhibitor. Binds to FKBP-12, forming a complex that inhibits calcineurin phosphatase, thereby blocking T-cell activation and IL-2 transcription.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ASTAGRAF XL and ENVARSUS XR depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ASTAGRAF XL is: Initial oral dose of 0.1-0.15 mg/kg/day divided every 12 hours, with subsequent adjustments based on trough levels. Typical maintenance dose 0.05-0.15 mg/kg/day.. The standard adult dose of ENVARSUS XR is: 0.2 mg/kg/day orally once daily, with the morning meal, using extended-release tablets. Dose adjustments guided by trough concentrations.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ASTAGRAF XL and ENVARSUS XR in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ASTAGRAF XL is classified as Category C. Tacrolimus is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, tacrolimus caused maternal toxicity an. ENVARSUS XR is classified as Category C. Envarsus XR (tacrolimus) is classified as FDA Pregnancy Category C. In the first trimester, there is an increased risk of congenital anomalies (e.g., cardiac, renal) based on anima. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.