Azathioprine

Common Use

Azathioprine is an immunosuppressant—in simple terms, it works by reducing the activity of the immune system. This helps prevent the body from rejecting transplanted organs and also helps control autoimmune diseases, where the immune system mistakenly attacks the body’s own tissues.

Azathioprine is used to treat a wide range of conditions:

Prevention of kidney transplant rejection – helps stop the body from rejecting a transplanted kidney

Rheumatoid arthritis – a chronic autoimmune condition causing joint pain, swelling, and stiffness

Chronic active hepatitis – a long-term inflammation of the liver

Systemic lupus erythematosus (lupus) – an autoimmune disease that can affect the skin, joints, kidneys, and other organs

Dermatomyositis – an inflammatory condition causing muscle weakness and skin rash

Periarteritis nodosa – a rare autoimmune condition that causes inflammation of the blood vessels

Acquired hemolytic anemia – a condition where the immune system destroys red blood cells

Idiopathic thrombocytopenic purpura (ITP) – a condition where the immune system destroys platelets, leading to easy bruising and bleeding

Gangrenous pyoderma – a rare skin condition that causes painful ulcers

Psoriasis – a chronic skin condition causing red, scaly patches

Crohn’s disease – an inflammatory bowel disease affecting the digestive tract

Ulcerative colitis – an inflammatory bowel disease affecting the colon

Myasthenia gravis – a condition causing muscle weakness

Pemphigus – a chronic blistering skin disease

Reiter’s syndrome (reactive arthritis) – an autoimmune condition triggered by an infection elsewhere in the body

Radiation dermatitis – skin damage caused by radiation therapy

Dosage and Direction

Take azathioprine with food to help reduce stomach upset. The dose is administered individually depending on the condition being treated, your body weight, and how well you respond to the medication. Follow all instructions from your physician carefully.

Do not take more than one dose of azathioprine at once.

Precautions

Do not stop taking this drug even if you do not feel improvement right away. Its effects may take several days or weeks to become noticeable. If you do not feel improvement after three months of treatment, inform your doctor

The risk of transplant rejection may remain high even after several years of treatment—continue taking your medication as prescribed

Regular blood tests for blood cell count should be performed:

Every week during the first eight weeks of treatment

Then at regular intervals as determined by your doctor

Avoid prolonged exposure to sunlight and UV rays, as this medication can increase the risk of skin cancer. Regular skin examinations are recommended

Patients with systemic diseases of joint tissues should not stop treatment without a doctor’s permission, as this may provoke a worsening (flare-up) of their condition

This medication may affect the immune status of an unborn baby. Inform your doctor if you are pregnant or breastfeeding

Notify your doctor immediately if you experience:

Fever, body aches, weakness, muscle pain, chills, or sore throat (signs of infection)

Easy bruising or bleeding

Mouth sores

Severe nausea or vomiting

Pale stools or darkened urine

Diarrhea

Contraindications

Azathioprine should not be administered to patients with:

Hypersensitivity (allergy) to azathioprine or any of its components

Inhibition of hematopoiesis – such as hypoplastic or aplastic anemia, leukopenia (low white blood cells), lymphopenia, or thrombocytopenia (low platelets)

Hepatic failure (severe liver impairment)

Pregnancy – can cause harm to the developing baby

Breastfeeding – passes into breast milk

Children – safety and effectiveness may vary; use only under specialist care

Possible Side Effects

Adverse reactions to azathioprine most commonly affect the blood and gastrointestinal system:

Blood-related effects:

White blood cell count may decrease – this increases the risk of developing infections. This effect usually reverses when the dose is reduced or temporarily stopped

Platelet count may decrease – leading to easy bruising or bleeding

Red blood cell count may decrease – causing anemia (fatigue, weakness)

Gastrointestinal effects:

Nausea and vomiting – these often improve when the dose is reduced or divided into several smaller doses throughout the day

Diarrhea

Other possible side effects:

Liver toxicity – may develop in patients with rheumatoid arthritis; your doctor will monitor liver function

Hair loss (temporary)

Joint pain

Fatigue

If you experience any side effects that become bothersome or severe, contact your doctor.

Drug Interactions

Approximately 200 drugs are known to interact with azathioprine. Inform your doctor about all prescribed and over-the-counter medications, herbal products, and food supplements you take.

Key interactions:

Allopurinol – a medication for gout; inhibits azathioprine metabolism, increasing its blood levels and toxicity. If you take allopurinol, your azathioprine dose will likely need to be reduced

Angiotensin-converting enzyme (ACE) inhibitors – may increase the risk of anemia and leukopenia when used with azathioprine

Warfarin and other indirect anticoagulants – azathioprine may reduce their effectiveness

Rifampicin – may increase the risk of graft rejection when used with azathioprine

Co-trimoxazole – may increase the myelotoxic (bone marrow suppressing) effect of azathioprine

Nondepolarizing muscle relaxants – azathioprine may reduce their effects

Suxamethonium – azathioprine may increase neuromuscular block

Missed Dose

If you miss a dose, take it as soon as you remember—unless it is almost time for your next dose. If that’s the case, skip the missed dose and continue with your regular schedule. Do not try to compensate for a missed dose by taking an extra one.

Overdose

If you think you have taken too much of this medicine, seek emergency medical attention right away. Very large doses may cause:

Marrow hypoplasia (severe bone marrow suppression)

Bleeding and infection

Nausea, vomiting, and diarrhea

Mild leukopenia (low white blood cells)

Mild liver impairment

In severe cases, overdose can be life-threatening.

Storage

Store azathioprine at room temperature between 15–25°C (59–77°F), away from light and moisture. Keep it out of reach of children and pets. Do not use the medication after the expiration date.

Disclaimer

We provide only general information about medications, which does not cover all directions, possible drug interactions, or precautions. Information on this site cannot be used for self-treatment or self-diagnosis. Any specific instructions for a particular patient should be agreed upon with your healthcare adviser or the doctor in charge of your case. We disclaim reliability of this information and any mistakes it may contain. We are not responsible for any direct, indirect, special, or other indirect damage as a result of any use of the information on this site, nor for the consequences of self-treatment.

About Our Service Cydoctors.com is an online pharmacy based right here in Cyprus. We understand that managing autoimmune conditions or preventing transplant rejection requires consistent, reliable access to your immunosuppressant medication—so we’ve made our service straightforward, dependable, and built with your peace of mind in mind. Because we’re local to the island, we can arrange delivery in the shortest possible time. For our customers in Nicosia, Limassol, and Larnaca, we’re pleased to offer overnight delivery, so your azathioprine can be with you by the next day, helping you stay on track with your treatment and protecting your health for the long term.