Mercaptopurine Silver: Uses, Dosage & Side Effects
Antimetabolite immunosuppressant — mercaptopurine 50 mg tablets
Quick Facts About Mercaptopurine Silver
Key Takeaways About Mercaptopurine Silver
- TPMT/NUDT15 testing is essential: Genetic testing before starting treatment identifies patients at risk of severe, life-threatening myelosuppression requiring dose reduction
- Critical drug interaction with allopurinol: Co-administration requires a 75% dose reduction of mercaptopurine to prevent fatal bone marrow toxicity
- Regular blood monitoring is mandatory: Complete blood counts and liver function tests must be performed frequently throughout treatment
- WHO Essential Medicine: Mercaptopurine is on the WHO Model List of Essential Medicines for the treatment of acute lymphoblastic leukemia
- Contraindicated in pregnancy: Both men and women must use effective contraception during treatment and for at least 3 months after discontinuation
What Is Mercaptopurine Silver and What Is It Used For?
Mercaptopurine Silver is a prescription medicine containing mercaptopurine (6-MP), a purine antimetabolite that works by interfering with DNA and RNA synthesis in rapidly dividing cells. It is primarily used for maintenance treatment of acute lymphoblastic leukemia (ALL) and as an immunosuppressant for inflammatory bowel disease and other autoimmune conditions.
Mercaptopurine, also known as 6-mercaptopurine or 6-MP, was first synthesized in 1951 by Gertrude Elion and George Hitchings at Burroughs Wellcome, work for which they later received the Nobel Prize in Physiology or Medicine in 1988. It has been a cornerstone of leukemia treatment for over seven decades and remains one of the most important drugs in pediatric oncology worldwide. The World Health Organization (WHO) includes mercaptopurine on its Model List of Essential Medicines, recognizing its critical role in cancer treatment globally.
Mercaptopurine belongs to the class of antimetabolites known as thiopurines. After oral administration, it is converted inside the body into active metabolites called 6-thioguanine nucleotides (6-TGN), which are incorporated into cellular DNA and RNA. This incorporation disrupts normal nucleic acid synthesis, leading to cell death in rapidly dividing cells such as cancer cells and activated immune cells. This dual mechanism makes mercaptopurine valuable both as an anticancer agent and as an immunosuppressant.
The primary approved indication for Mercaptopurine Silver is the maintenance treatment of acute lymphoblastic leukemia (ALL), the most common childhood cancer. In ALL treatment protocols, mercaptopurine is typically used during the maintenance phase, which lasts 2–3 years, in combination with methotrexate. This prolonged maintenance therapy has been shown in landmark clinical trials to significantly improve long-term disease-free survival rates, which now exceed 85–90% in children with standard-risk ALL according to NCCN guidelines.
Beyond its oncological applications, mercaptopurine has become widely used off-label as an immunosuppressant in several autoimmune and inflammatory conditions. Its prodrug azathioprine (which is converted to mercaptopurine in the body) is more commonly prescribed for these indications, but mercaptopurine itself is increasingly preferred in certain situations, particularly in inflammatory bowel disease (IBD). Clinical evidence from multiple randomized controlled trials and systematic reviews supports the use of mercaptopurine in maintaining remission in both Crohn’s disease and ulcerative colitis, especially in patients who are steroid-dependent or steroid-refractory.
Mercaptopurine and azathioprine are closely related drugs. Azathioprine is a prodrug that is converted to mercaptopurine in the body. However, the two drugs are not interchangeable on a milligram-for-milligram basis. The conversion factor is approximately 55% (i.e., 50 mg of azathioprine yields approximately 27.5 mg of mercaptopurine). Dose adjustments are always necessary when switching between these medications.
What Should You Know Before Taking Mercaptopurine Silver?
Before starting Mercaptopurine Silver, you must undergo TPMT and NUDT15 genetic testing to determine your ability to metabolize the drug safely. Patients with reduced enzyme activity require significant dose reductions to avoid life-threatening bone marrow suppression. A thorough medication review is essential as several common drugs interact dangerously with mercaptopurine.
Mercaptopurine is a potent medication with a narrow therapeutic index, meaning there is a small margin between an effective dose and a toxic dose. Before initiating treatment, your healthcare provider will conduct a comprehensive assessment including blood tests, liver function tests, and crucially, pharmacogenomic testing for the enzymes TPMT (thiopurine methyltransferase) and NUDT15 (nucleoside diphosphate-linked moiety X-type motif 15). The results of these tests directly influence the safe starting dose of mercaptopurine.
Contraindications
Mercaptopurine Silver is contraindicated in the following situations:
- Known hypersensitivity to mercaptopurine or any of the excipients in the formulation
- Absent TPMT and/or NUDT15 activity (homozygous deficient patients) — these patients cannot safely metabolize mercaptopurine at any standard dose and are at extreme risk of fatal myelosuppression
- Concurrent use with live vaccines — the immunosuppressive effect of mercaptopurine may lead to disseminated vaccine-strain infections
- Severe hepatic impairment — mercaptopurine undergoes extensive hepatic metabolism and may accumulate to toxic levels
- Severe active infection — further immunosuppression may lead to overwhelming sepsis
Warnings and Precautions
Several important warnings apply to the use of mercaptopurine. Myelosuppression (bone marrow suppression) is the most clinically significant toxicity. This manifests as leukopenia (low white blood cells), thrombocytopenia (low platelets), and anemia, which increase the risk of serious infections and bleeding. Regular complete blood count (CBC) monitoring is mandatory — typically weekly during the first 8 weeks of treatment, then at least monthly thereafter. Any unexpected drop in blood counts should prompt immediate dose reduction or temporary discontinuation.
Hepatotoxicity is another significant concern. Mercaptopurine can cause cholestatic jaundice, hepatic necrosis, and veno-occlusive disease (sinusoidal obstruction syndrome), particularly at higher doses. Liver function tests (LFTs) should be monitored regularly throughout treatment. If transaminase levels rise to more than three times the upper limit of normal, treatment should be interrupted and the dose reduced upon rechallenge.
There is an increased risk of secondary malignancies associated with long-term immunosuppressive therapy, including an elevated risk of lymphoma and hepatosplenic T-cell lymphoma, particularly in young males with IBD treated with thiopurines. Additionally, patients on mercaptopurine have an increased susceptibility to skin cancer, and sun protection measures are recommended throughout treatment. The risk of Epstein-Barr virus (EBV)-related lymphoproliferative disorders is also elevated, especially in EBV-seronegative patients.
Macrophage activation syndrome (MAS) has been reported in patients with autoimmune conditions receiving mercaptopurine, particularly those with active inflammatory disease. This is a potentially fatal condition characterized by persistent fever, cytopenias, and multi-organ dysfunction, requiring immediate specialist intervention.
Approximately 10% of the population has intermediate TPMT activity and 0.3% has very low or absent activity. Patients with NUDT15 variants are especially common in East Asian populations (up to 2%). These patients accumulate toxic levels of 6-TGN metabolites and are at extreme risk of severe, potentially fatal myelosuppression. The Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines strongly recommend genotyping or phenotyping before starting therapy, with dose reductions of 30–80% for intermediate metabolizers and avoidance or extreme dose reduction for poor metabolizers.
Pregnancy and Breastfeeding
Mercaptopurine is classified as a teratogen based on animal data showing congenital malformations and human observational data suggesting increased risks of preterm birth, low birth weight, and congenital anomalies. The European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) both recommend avoiding mercaptopurine during pregnancy unless the benefit clearly outweighs the risk, such as in the treatment of leukemia where alternative therapy is not available.
Both men and women of reproductive potential should use effective contraception during treatment and for at least 3 months after discontinuation. Men should be counselled that mercaptopurine may reduce sperm count and quality, and fertility preservation should be discussed before starting therapy. If pregnancy occurs during treatment, immediate referral to a maternal-fetal medicine specialist is essential for risk assessment.
Mercaptopurine is excreted in breast milk, and breastfeeding is contraindicated during treatment. The immunosuppressive and cytotoxic properties of the drug pose a risk of adverse effects in the nursing infant, including bone marrow suppression and increased infection susceptibility.
How Does Mercaptopurine Silver Interact with Other Drugs?
Mercaptopurine has several critical drug interactions, the most dangerous being with allopurinol, which requires a 75% dose reduction. Other important interactions include aminosalicylates (which inhibit TPMT), warfarin, methotrexate, and live vaccines. Always inform your healthcare provider of all medications you are taking.
Drug interactions with mercaptopurine can have life-threatening consequences due to its narrow therapeutic index. The metabolism of mercaptopurine involves three competing enzyme pathways: thiopurine methyltransferase (TPMT), which produces inactive metabolites; xanthine oxidase (XO), which produces inactive thiouric acid; and hypoxanthine-guanine phosphoribosyltransferase (HGPRT), which produces the active and potentially toxic 6-thioguanine nucleotides (6-TGN). Drugs that inhibit TPMT or XO shift metabolism toward the HGPRT pathway, increasing 6-TGN levels and the risk of toxicity.
Major Interactions
| Drug | Mechanism | Clinical Effect | Action Required |
|---|---|---|---|
| Allopurinol | Inhibits xanthine oxidase | Up to 4-fold increase in mercaptopurine levels; severe myelosuppression | Reduce mercaptopurine dose by 75%; close monitoring |
| Febuxostat | Inhibits xanthine oxidase | Similar to allopurinol; increased toxicity risk | Combination generally contraindicated |
| Aminosalicylates (mesalazine, sulfasalazine, olsalazine) | Inhibit TPMT enzyme | Increased 6-TGN levels; higher risk of myelosuppression | Dose reduction; increased blood count monitoring |
| Live vaccines (MMR, varicella, BCG, yellow fever) | Immunosuppression from mercaptopurine | Risk of disseminated vaccine-strain infection | Contraindicated; use inactivated vaccines instead |
| Methotrexate | Inhibits first-pass metabolism; increases bioavailability | Increased mercaptopurine exposure; enhanced efficacy and toxicity | Used therapeutically in ALL protocols; dose adjustment required |
Minor Interactions
| Drug | Mechanism | Clinical Effect | Action Required |
|---|---|---|---|
| Warfarin | Reduced anticoagulant absorption or enhanced metabolism | Decreased INR; reduced anticoagulation | Monitor INR closely; adjust warfarin dose |
| ACE inhibitors | Additive leukopenia risk | Increased risk of infection | Monitor white blood cell counts |
| Trimethoprim-sulfamethoxazole | Additive bone marrow suppression | Increased risk of pancytopenia | Monitor CBC; consider alternative antibiotics |
| Ribavirin | Inhibits inosine monophosphate dehydrogenase | Increased active metabolite levels | Avoid combination; monitor if unavoidable |
Patients should inform their healthcare provider about all medications, including over-the-counter drugs, herbal supplements, and vitamins, before starting mercaptopurine therapy. Even seemingly innocuous products can influence the metabolism or effects of mercaptopurine, and unexpected interactions can have serious consequences.
What Is the Correct Dosage of Mercaptopurine Silver?
The standard adult dosage of mercaptopurine for leukemia maintenance is 1.5–2.5 mg/kg/day orally, adjusted based on blood counts and TPMT/NUDT15 genotype. For inflammatory bowel disease, the typical dose is 1–1.5 mg/kg/day. Dosing must be individualized, and regular blood monitoring is essential for safe use.
Mercaptopurine dosing is highly individualized and depends on the specific indication, the patient’s weight, renal and hepatic function, concurrent medications, and most importantly, the results of TPMT and NUDT15 genotyping. The treating physician will determine the optimal dose based on these factors and adjust it according to clinical response and laboratory monitoring. Self-adjustment of doses without medical guidance is dangerous and potentially life-threatening.
Adults
Acute Lymphoblastic Leukemia (ALL) — Maintenance
Standard dose: 1.5–2.5 mg/kg/day (approximately 75–100 mg/m²/day) as a single daily dose, taken in the evening on an empty stomach. The dose is adjusted to maintain a white blood cell count within the target range specified by the treating oncologist, typically between 2,000–3,000/µL. Treatment duration is usually 2–3 years as part of a multi-drug maintenance protocol that also includes weekly methotrexate.
Inflammatory Bowel Disease (Off-label)
Standard dose: 1–1.5 mg/kg/day (typically 50–100 mg/day), taken as a single daily dose. Therapeutic onset is slow, typically requiring 3–6 months before full clinical effect is observed. The dose is titrated based on clinical response, blood counts, and where available, 6-TGN metabolite levels (target range: 230–450 pmol/8×108 red blood cells).
Children
Pediatric ALL — Maintenance
Standard dose: 1.5–2.5 mg/kg/day or 50–75 mg/m²/day. Children follow specific treatment protocols (e.g., COG, BFM, UKALL) that precisely define the target dose and dose modification rules. Adherence to the prescribed maintenance regimen is critical for long-term cure rates. The 50 mg tablet may need to be split or a liquid formulation used for accurate dosing in smaller children. Evening administration on an empty stomach (at least 1 hour after food and at least 2 hours before the next meal) may improve absorption and reduce variability.
Elderly
Dose Adjustment in Older Adults
No specific dose adjustment is mandated solely based on age. However, elderly patients are more likely to have reduced renal and hepatic function, and they may be more susceptible to myelosuppression and hepatotoxicity. Initiating therapy at the lower end of the dosing range and monitoring more frequently is prudent. Concurrent medications (polypharmacy) should be carefully reviewed for potential interactions.
| Phenotype | TPMT Activity | Population Frequency | Dose Recommendation |
|---|---|---|---|
| Normal metabolizer | Normal/high | ~86% | Full standard dose |
| Intermediate metabolizer | Reduced | ~10% | Start at 30–80% of standard dose; titrate based on tolerance |
| Poor metabolizer | Very low/absent | ~0.3% | Drastically reduce to 10% of standard dose; consider alternative therapy |
| NUDT15 intermediate | Normal TPMT | ~2% (East Asian) | Start at 25–50% of standard dose |
Missed Dose
If you miss a dose of Mercaptopurine Silver, take it as soon as you remember, unless it is almost time for your next dose. In that case, skip the missed dose and continue with your regular schedule. Do not take a double dose to make up for a missed one, as this increases the risk of toxicity. If you frequently forget doses, discuss strategies with your healthcare provider, as inconsistent dosing can reduce treatment effectiveness, particularly in leukemia maintenance.
Overdose
An overdose of mercaptopurine is a medical emergency. Symptoms of overdose may not appear immediately but can develop over several days to weeks and include severe nausea, vomiting, diarrhea, and progressive bone marrow failure (leukopenia, thrombocytopenia, and anemia). There is no specific antidote for mercaptopurine overdose. Treatment is supportive and includes immediate gastric decontamination if within 1–2 hours of ingestion, aggressive blood product support, and monitoring in a hematology or intensive care setting. Contact your local poison control center or emergency services immediately.
What Are the Side Effects of Mercaptopurine Silver?
The most significant side effects of mercaptopurine include bone marrow suppression (leukopenia, thrombocytopenia, anemia), hepatotoxicity, nausea, and increased susceptibility to infections. Side effect severity is closely related to dose and individual metabolizer status. Regular blood monitoring allows early detection and management of most adverse effects.
Like all cytotoxic and immunosuppressive medications, mercaptopurine can cause a range of side effects. The severity and frequency of these effects vary considerably between individuals and are strongly influenced by the dose, duration of treatment, concurrent medications, and the patient’s TPMT/NUDT15 metabolizer status. Most common side effects are dose-dependent and can often be managed through careful dose adjustment and supportive care.
It is important to note that not all patients experience side effects, and many patients tolerate mercaptopurine well at appropriate doses. The benefit-risk ratio should always be considered in the context of the condition being treated. For leukemia treatment, the life-saving potential of the medication clearly outweighs the risk of manageable side effects in most cases.
Very Common (>1 in 10 patients)
- Myelosuppression — leukopenia (low white blood cells), neutropenia, anemia, thrombocytopenia
- Nausea — often manageable with timing of administration and anti-emetics
- Loss of appetite (anorexia) — may contribute to weight loss during treatment
- Increased infection susceptibility — due to immunosuppression; both bacterial and opportunistic infections
Common (1 in 10 to 1 in 100 patients)
- Hepatotoxicity — elevated transaminases (ALT, AST), cholestatic jaundice
- Vomiting — may require dose adjustment or anti-emetic therapy
- Oral mucositis — mouth ulcers and stomatitis
- Diarrhea — usually mild to moderate
- Skin rash — various dermatological reactions
- Arthralgia — joint pain, especially during early treatment
Uncommon (1 in 100 to 1 in 1,000 patients)
- Pancreatitis — can be severe; requires immediate discontinuation; idiosyncratic reaction
- Fever — drug-related or due to occult infection
- Veno-occlusive disease (sinusoidal obstruction syndrome) — a serious hepatic complication
- Hypersensitivity reactions — rash, fever, joint pain
Rare (<1 in 1,000 patients)
- Secondary malignancies — lymphoma, particularly hepatosplenic T-cell lymphoma in young males with IBD
- Intestinal ulceration — particularly at higher doses
- Alopecia — usually mild and reversible
- Oligospermia — reduced sperm production; usually reversible on discontinuation
- Crystalluria — crystal formation in urine at very high doses
Contact your healthcare provider or seek emergency care immediately if you experience: unexplained fever or chills (may indicate infection due to low white blood cells), unusual bruising or bleeding (may indicate low platelets), persistent severe nausea or vomiting, yellowing of the skin or eyes (jaundice), severe abdominal pain (may indicate pancreatitis), or dark urine. These may be signs of serious complications requiring urgent medical evaluation.
How Should You Store Mercaptopurine Silver?
Store Mercaptopurine Silver tablets below 25°C (77°F) in the original packaging to protect from moisture and light. Keep out of reach of children. As a cytotoxic agent, unused or expired tablets must be returned to a pharmacy for safe disposal.
Proper storage of Mercaptopurine Silver is essential to maintain the drug’s effectiveness and safety. The tablets should be stored at controlled room temperature, below 25°C (77°F), in a dry place. Avoid storing the medication in bathrooms or areas with high humidity, as moisture can degrade the active ingredient. Keep the tablets in their original blister pack or container until the time of administration to protect them from light exposure.
Since mercaptopurine is a cytotoxic (cell-killing) medication, special handling precautions apply. Tablets should not be crushed, split, or chewed unless specifically instructed by a pharmacist, as this can release cytotoxic dust. If tablet splitting is necessary for accurate dosing (particularly in pediatric patients), it should be done using a tablet cutter and the hands should be washed thoroughly afterward. Pregnant women and caregivers who are pregnant or planning pregnancy should avoid handling broken or crushed tablets.
Do not use Mercaptopurine Silver after the expiry date printed on the packaging (month/year). The expiry date refers to the last day of that month. Unused or expired tablets should not be disposed of via household waste or flushed down the toilet. Instead, return them to a pharmacy for proper disposal through a cytotoxic waste management program to prevent environmental contamination.
Keep all medications out of the sight and reach of children. Accidental ingestion of even a single tablet by a child can cause serious toxicity. Store the medication in a secure, locked location if children are present in the household. In case of accidental ingestion by a child, contact your local poison control center immediately.
What Does Mercaptopurine Silver Contain?
Each Mercaptopurine Silver tablet contains 50 mg of mercaptopurine (also known as 6-mercaptopurine or 6-MP) as the active ingredient. The tablets also contain inactive excipients necessary for manufacturing and stability.
The active pharmaceutical ingredient in Mercaptopurine Silver is mercaptopurine (International Nonproprietary Name: mercaptopurine; chemical name: 6-mercaptopurine monohydrate, also known as 1,7-dihydro-6H-purine-6-thione). Each tablet contains mercaptopurine equivalent to 50 mg of anhydrous mercaptopurine. Mercaptopurine is a sulfur-containing analogue of the natural purine base hypoxanthine, and its structural similarity to endogenous purines is the basis for its antimetabolite mechanism of action.
The tablet formulation also contains inactive excipients (non-active ingredients) that serve various pharmaceutical purposes such as binding, filling, disintegration, and lubrication. Typical excipients in mercaptopurine tablet formulations include:
- Lactose monohydrate — filler/diluent (patients with lactose intolerance should discuss this with their pharmacist)
- Maize starch — binder and disintegrant
- Stearic acid — lubricant to facilitate tablet manufacturing
- Magnesium stearate — lubricant
- Microcrystalline cellulose — binder and filler
Patients with known allergies to any of the excipients should inform their healthcare provider or pharmacist before starting treatment. The specific excipient composition may vary between manufacturers, so always refer to the package insert provided with your specific medication for the complete list of ingredients.
Mercaptopurine is absorbed from the gastrointestinal tract with variable oral bioavailability (approximately 16–50%) due to extensive first-pass metabolism. Peak plasma concentrations occur approximately 1–2 hours after oral administration. The drug has a relatively short plasma half-life of approximately 1–2 hours, but the active metabolites (6-TGN) have a much longer intracellular half-life of approximately 5–9 days, which is why once-daily dosing is sufficient. Food can reduce absorption; therefore, the drug should be taken on an empty stomach for optimal and consistent absorption.
Frequently Asked Questions About Mercaptopurine Silver
Mercaptopurine Silver contains mercaptopurine (6-MP), primarily used in the maintenance treatment of acute lymphoblastic leukemia (ALL), the most common childhood cancer. It is also widely used off-label as an immunosuppressant for inflammatory bowel disease (Crohn's disease and ulcerative colitis), autoimmune hepatitis, and other autoimmune conditions. It works by inhibiting DNA and RNA synthesis in rapidly dividing cells, making it effective both as an anti-cancer drug and an immunosuppressant.
TPMT (thiopurine methyltransferase) is an enzyme that metabolizes mercaptopurine. About 10% of the population has reduced TPMT activity and 0.3% has very low or absent activity. Patients with low TPMT accumulate toxic levels of active metabolites, which can cause severe, life-threatening bone marrow suppression (myelosuppression). Testing before treatment allows your doctor to adjust the dose appropriately, or choose an alternative medication, to prevent this potentially fatal complication. NUDT15 testing is equally important, especially in patients of East Asian descent.
This is one of the most critical drug interactions in medicine. Allopurinol inhibits xanthine oxidase, one of the main enzymes that breaks down mercaptopurine. When taken together without dose adjustment, mercaptopurine levels can increase up to 4-fold, causing severe and potentially fatal bone marrow toxicity. If allopurinol cannot be avoided, the mercaptopurine dose must be reduced to approximately 25% of the standard dose (a 75% reduction). Blood counts must be monitored very closely. Always tell your doctor about all medications you take, including those for gout.
The most common side effects include bone marrow suppression (low white blood cells, low platelets, anemia), nausea, loss of appetite, and increased susceptibility to infections. Hepatotoxicity (liver damage with elevated enzymes) is also relatively common. Less common but serious side effects include pancreatitis, veno-occlusive disease of the liver, and secondary malignancies with long-term use. Most side effects are dose-dependent and can often be managed through dose adjustment. Regular blood monitoring is essential to catch problems early.
Mercaptopurine is classified as a teratogen and should be avoided during pregnancy whenever possible. Both men and women should use effective contraception during treatment and for at least 3 months after stopping. If pregnancy occurs during treatment, immediate specialist referral is essential. In some cases, such as leukemia treatment where no alternative exists, the benefit may outweigh the risk, but this decision requires careful specialist assessment. Breastfeeding is also contraindicated during treatment.
Store Mercaptopurine Silver tablets below 25°C (77°F) in the original packaging to protect from moisture and light. Keep out of reach and sight of children. Do not use after the expiry date. Since this is a cytotoxic medication, unused or expired tablets should be returned to a pharmacy for safe disposal — do not flush them or put them in household waste. Pregnant women should avoid handling broken or crushed tablets.
References
This article is based on international guidelines, systematic reviews, and peer-reviewed research. All medical claims are supported by evidence level 1A where available.
- World Health Organization (WHO). WHO Model List of Essential Medicines — 23rd List. Geneva: WHO; 2023. Mercaptopurine listed as essential medicine for acute lymphoblastic leukemia.
- Relling MV, Schwab M, Whirl-Carrillo M, et al. Clinical Pharmacogenetics Implementation Consortium Guideline for Thiopurine Dosing Based on TPMT and NUDT15 Genotypes: 2018 Update. Clinical Pharmacology & Therapeutics. 2019;105(5):1095-1105. doi:10.1002/cpt.1304
- European Medicines Agency (EMA). Summary of Product Characteristics: Mercaptopurine 50 mg Tablets. EMA; 2024.
- National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Acute Lymphoblastic Leukemia. Version 2.2024.
- Prefontaine E, Sutherland LR, Macdonald JK, Cepoiu M. Azathioprine or 6-mercaptopurine for maintenance of remission in Crohn's disease. Cochrane Database of Systematic Reviews. 2009;(1):CD000067.
- Gearry RB, Barclay ML. Azathioprine and 6-mercaptopurine pharmacogenetics and metabolite monitoring in inflammatory bowel disease. Journal of Gastroenterology and Hepatology. 2005;20(8):1149-1157.
- Schmiegelow K, Nielsen SN, Frandsen TL, Nersting J. Mercaptopurine/Methotrexate maintenance therapy of childhood acute lymphoblastic leukemia: clinical facts and fiction. Journal of Pediatric Hematology/Oncology. 2014;36(7):503-517.
- British National Formulary (BNF). Mercaptopurine. National Institute for Health and Care Excellence (NICE); 2024.
- US Food and Drug Administration (FDA). Purixan (mercaptopurine) oral suspension prescribing information. FDA; 2023.
- European Society for Medical Oncology (ESMO). Clinical Practice Guidelines: Acute Lymphoblastic Leukemia. 2024.
Editorial Team
This article has been written and reviewed by our medical editorial team in accordance with international clinical guidelines and evidence-based medicine standards.
Medical Content
Written by iMedic Medical Editorial Team — Specialists in Clinical Pharmacology and Oncology
Medical Review
Reviewed by iMedic Medical Review Board according to WHO, EMA, FDA, and NCCN guidelines
Evidence Level
Level 1A — Based on systematic reviews and meta-analyses of randomized controlled trials (GRADE framework)
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