Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
GENGRAF vs AZASAN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Calcineurin inhibitor; binds to cyclophilin, inhibits calcineurin-dependent T-cell activation, preventing nuclear factor of activated T-cells (NF-AT) dephosphorylation and translocation, thereby reducing IL-2 and other cytokine gene transcription.
Azathioprine is a purine analog that inhibits purine synthesis, thereby interfering with DNA and RNA synthesis. It is metabolized to 6-mercaptopurine, which inhibits T-cell activation and proliferation, leading to immunosuppression.
Prophylaxis of organ rejection in kidney, liver, and heart allogeneic transplants,Treatment of active rheumatoid arthritis (FDA-approved for moderate to severe),Treatment of psoriasis (FDA-approved for severe, recalcitrant cases),Off-label: nephrotic syndrome, aplastic anemia, ulcerative colitis, atopic dermatitis
Renal transplant rejection prophylaxis,Rheumatoid arthritis,Off-label: inflammatory bowel disease (Crohn's disease, ulcerative colitis), lupus nephritis, autoimmune hepatitis, pemphigus vulgaris, myasthenia gravis, Behçet's disease, dermatomyositis, polymyositis
5-15 mg/kg/day orally in divided doses every 12 hours.
1-3 mg/kg/day orally once daily or divided twice daily; maximum dose 2.5 mg/kg/day for rheumatoid arthritis; usual dose 50-150 mg/day.
Terminal half-life is approximately 8.4 hours (range 5-18 hours) in adult volunteers; prolonged in hepatic impairment.
Terminal elimination half-life of azathioprine is approximately 4.5 hours (range 2–6 h), while its active metabolite 6-mercaptopurine has a half-life of 0.5–2 hours. Clinical context: Renal impairment prolongs half-life.
Hepatic metabolism primarily via CYP3A4 enzyme; also substrate for CYP3A5. Metabolized to multiple metabolites with variable activity, including AM1 (hydroxylated), AM9 (N-demethylated), and AM4N (cyclized). Undergoes extensive first-pass metabolism.
Metabolized via xanthine oxidase and thiopurine methyltransferase (TPMT) to active and inactive metabolites. Co-administration with allopurinol inhibits xanthine oxidase, requiring dose reduction of azathioprine.
Primarily biliary/fecal (94%); renal excretion accounts for 6% (0.1% unchanged).
Renal: 88% as 6-mercaptopurine and metabolites; biliary: <10%
90-98% bound to plasma proteins, primarily lipoproteins, albumin, and alpha-1-acid glycoprotein.
30% bound to plasma proteins, primarily albumin.
3.5 L/kg (range 1.2-4.8 L/kg) in renal transplant recipients; distribution is extensive and variable.
0.8–1.0 L/kg, indicating extensive distribution into tissues.
Oral bioavailability is 30% (range 10-60%), variable due to first-pass metabolism and food effects.
Oral: 41–47% (azathioprine); 100% for IV administration.
GFR <30 m L/min: reduce dose by 50%.
GFR >50 m L/min: no adjustment; GFR 10-50 m L/min: 75% of normal dose; GFR <10 m L/min: 50% of normal dose.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use.
Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50%; Child-Pugh Class C: contraindicated.
4-10 mg/kg/day orally in divided doses every 12 hours; adjusted to target trough levels.
2-3 mg/kg/day orally once daily; initial dose 1 mg/kg/day in divided doses; not recommended in children <1 year.
Initiate at lower end of dosing range and titrate based on renal function and drug levels.
Start at low end of dosing range (50 mg once daily); monitor renal function and adjust accordingly.
Increased susceptibility to infection and development of lymphoma and other malignancies, particularly of the skin. Only physicians experienced in immunosuppressive therapy and management of transplant patients should prescribe cyclosporine.
Chronic immunosuppression increases the risk of malignancy, particularly lymphoma and skin cancer. Patients should be monitored for neoplasia. The drug should be used only if potential benefits outweigh risks.
Nephrotoxicity: Monitor renal function regularly; risk increased with high doses, other nephrotoxic drugs, or prolonged use.,Hepatotoxicity: Monitor liver function.,Hypertension: Common; require blood pressure control.,Neurotoxicity: Including tremor, convulsions, headache, and paresthesias.,Hyperkalemia: Monitor serum potassium, especially with potassium-sparing diuretics or ACE inhibitors.,Hypomagnesemia: Supplementation may be required.,Increased risk of infections and lymphoproliferative disorders.,Potential for anaphylactic reactions with IV formulation (due to Cremophor EL).,Carcinogenesis: Especially skin malignancies; minimize UV exposure.
Hematologic toxicity (leukopenia, thrombocytopenia, anemia) - monitor blood counts. Hepatotoxicity. Increased infection risk. Hypersensitivity reactions. TPMT deficiency increases toxicity risk. Monitor for pancreatitis, especially in Crohn's patients. Avoid live vaccines. Photosensitivity and skin cancer risk.
Hypersensitivity to cyclosporine or any component of the formulation (including Cremophor EL for IV),Uncontrolled hypertension,Malignancy (except non-melanoma skin cancer) in patients with rheumatoid arthritis or psoriasis,Concomitant use with PUVA or UVB therapy, methotrexate, other immunosuppressive agents, or coal tar (for psoriasis patients),Abnormal renal function with uncontrolled hypertension (for psoriasis patients),Pregnancy (category C; additional risk of premature birth and low birth weight)
Hypersensitivity to azathioprine or 6-mercaptopurine. Pregnancy (category D) unless potential benefit justifies risk. Lactation. Severe hepatic impairment. Myelosuppression or active infection. Concurrent use with allopurinol without dose adjustment.
Grapefruit and grapefruit juice increase cyclosporine levels and must be avoided. High-potassium foods (e.g., bananas, oranges, potatoes) may increase hyperkalemia risk; monitor intake. Avoid St. John's wort as it reduces drug levels.
No significant food interactions. May be taken with food to reduce gastrointestinal upset. Avoid concurrent use with raw or undercooked meats to reduce risk of infection due to immunosuppression.
First trimester: Cyclosporine crosses the placenta. Limited human data, but no major malformations attributed. Second and third trimesters: Risk of intrauterine growth restriction, prematurity, and low birth weight. Consider risk-benefit; avoid if possible, but may be used if essential.
Azathioprine is FDA Pregnancy Category D. First trimester: Associated with congenital anomalies (e.g., atrial septal defect, limb defects) in case reports, but risk may be lower than with other immunosuppressants. Second and third trimesters: Risk of fetal growth restriction, preterm delivery, and neonatal immunosuppression. Avoid unless benefit outweighs risk.
Cyclosporine is excreted into breast milk. Milk-to-plasma ratio approximately 0.3-0.6. Potential for infant immunosuppression and growth inhibition. Weigh benefits against risks; monitor infant for adverse effects.
Azathioprine is excreted into breast milk in small amounts; milk-to-plasma ratio approximately 0.1. Infant exposure is low, but theoretical risk of immunosuppression. Weigh benefits against risks; consider monitoring infant for leukopenia and infections.
Pregnancy reduces cyclosporine oral bioavailability and increases clearance; dose may need to be increased by 20-50% to maintain therapeutic trough levels. Frequent level monitoring recommended, especially in third trimester. Postpartum dose reduction likely needed.
Increased clearance and reduced bioavailability during pregnancy may require dose increase to maintain therapeutic levels; monitor thiopurine metabolite levels (6-TGN, 6-MMP) and adjust accordingly. Often no change required if stable disease.
Monitor trough levels (target 100-400 ng/m L) and renal function closely. Calcineurin inhibitors cause nephrotoxicity; dose reduction may be necessary. Avoid use with potassium-sparing diuretics or ACE inhibitors due to hyperkalemia risk. Grapefruit increases levels; avoid coadministration. Remember to adjust dose for hepatic impairment.
Azasan (azathioprine) is a prodrug of 6-mercaptopurine. Screen for TPMT deficiency before initiation to avoid severe myelosuppression. Monitor CBC and liver function weekly for first month, then monthly. Corticosteroid-sparing agent in autoimmune conditions. Avoid live vaccines during therapy.
Take with or without food consistently at the same times each day.,Do not consume grapefruit or grapefruit juice while on this medication.,Report signs of infection, tremors, or changes in urine output immediately.,Avoid live vaccinations and limit sun exposure due to increased skin cancer risk.,Do not stop or change dose without consulting your doctor.
Take exactly as prescribed; do not change dose without consulting your doctor.,Report any signs of infection, unusual bruising/bleeding, or fatigue immediately.,Avoid exposure to individuals with infections; maintain good hand hygiene.,Use effective contraception during treatment and for at least 3 months after stopping.,Do not receive live vaccines (e.g., MMR, varicella) while taking this medication.,Limit sun exposure; use sunscreen and protective clothing due to increased skin cancer risk.
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 GENGRAF vs AZASAN, answered by our medical review team.
GENGRAF is a Calcineurin Inhibitor Immunosuppressant that works by Calcineurin inhibitor; binds to cyclophilin, inhibits calcineurin-dependent T-cell activation, preventing nuclear factor of activated T-cells (NF-AT) dephosphorylation and translocation, thereby reducing IL-2 and other cytokine gene transcription.. AZASAN is a Immunosuppressant that works by Azathioprine is a purine analog that inhibits purine synthesis, thereby interfering with DNA and RNA synthesis. It is metabolized to 6-mercaptopurine, which inhibits T-cell activation and proliferation, leading to immunosuppression.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between GENGRAF and AZASAN 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 GENGRAF is: 5-15 mg/kg/day orally in divided doses every 12 hours.. The standard adult dose of AZASAN is: 1-3 mg/kg/day orally once daily or divided twice daily; maximum dose 2.5 mg/kg/day for rheumatoid arthritis; usual dose 50-150 mg/day.. 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 GENGRAF and AZASAN 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. GENGRAF is classified as Category C. First trimester: Cyclosporine crosses the placenta. Limited human data, but no major malformations attributed. Second and third trimesters: Risk of intrauterine growth restriction,. AZASAN is classified as Category C. Azathioprine is FDA Pregnancy Category D. First trimester: Associated with congenital anomalies (e.g., atrial septal defect, limb defects) in case reports, but risk may be lower th. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.