Azathioprine
Azathioprine is an immunosuppressant tablet used in severe rheumatoid arthritis and to help prevent kidney transplant rejection, sold as Imuran in 25mg and 50mg strengths.
What azathioprine is used for
Two situations bring most people to azathioprine. After a kidney transplant it is given alongside other medicines so the body does not reject the new organ. In severe rheumatoid arthritis, where the body's own defences attack the joints and cause pain, swelling and stiffness, it is used when other treatments have not done enough. Lupus, Crohn's disease and ulcerative colitis are further long-term conditions it is used for.
Weeks, not days
Expect a slow start. Days in, nothing seems different; weeks in, some people notice a change, and in rheumatoid arthritis the full benefit can take up to twelve weeks. The reason is how it works: azathioprine is a purine analogue, imitating a building block of DNA, so the white blood cells that drive inflammation multiply less quickly.
Tablets go down whole with water, once or twice a day, after a meal if the stomach protests. The dose starts low and rises over six to eight weeks in rheumatoid arthritis, with blood counts deciding each step.
Side effects worth knowing
Nausea, vomiting, going off food, tiredness and thinning hair are the complaints people report most, and many ease as the body adjusts. The heavier risk sits in the bone marrow, where the drug can cut the number of blood cells produced; that can show as infections slow to clear, a sore throat with fever and chills, or bruising and bleeding more easily than before. Blood counts are checked before and during treatment for that reason. Years of use also raise the chance of some cancers, particularly skin cancer and lymphoma, which is one reason to cover up and use sunscreen in strong sun. A rare lymphoma of the liver and spleen has been reported in teenage and young adult men treated for Crohn's disease or ulcerative colitis, and a study of pregnant women with lupus linked azathioprine exposure to intrahepatic cholestasis of pregnancy, a liver condition that appears after 20 weeks.
Interactions with other medicines
Several common medicines change what azathioprine does. Allopurinol for gout slows its breakdown and raises its level in the body, so the two together need a careful dose adjustment. Others add to the fall in blood cells: the antibiotic combination co-trimoxazole (trimethoprim with sulfamethoxazole), ACE inhibitors for blood pressure such as enalapril and ramipril, and the antiviral ribavirin.
Ordering azathioprine tablets
Imuran is the brand name on the azathioprine tablets sold here, in 25mg and 50mg, and the same tablets are also sold under the plain name azathioprine. Both belong to the Autoimmune Care range. The 25mg tablet allows smaller steps when a dose changes, while 50mg keeps the tablet count down when the daily amount is high.
Sources
- Azathioprine: MedlinePlus Drug Information — MedlinePlus / U.S. National Library of Medicine
- AZATHIOPRINE tablet label — DailyMed
Is Azathioprine available to order in Hong Kong?
Azathioprine can be ordered online with delivery to Hong Kong. The range covers generic Imuran, also sold as Azathioprine tablets, as tablets in 25mg and 50mg. Payment is by Visa, Mastercard or American Express on a secure, encrypted payment page, or by Bitcoin or Ethereum.
How much do Azathioprine products cost in Hong Kong?
Prices vary between pack sizes. The product page lists its current prices in HKD or in the currency you choose.
Is there a generic Imuran?
Yes, generic Imuran is listed as 25mg and 50mg tablets and contains azathioprine. It is also sold as Azathioprine tablets, the plain version, in the same 25mg and 50mg tablets.
What are the brand names for azathioprine?
Imuran is a brand name of azathioprine, which is also sold as Imurel and Azamun. Here, azathioprine can be bought online as generic Imuran. These are generics, not the original brand.
Can you take azathioprine with food?
Yes. Tablets are usually taken after a meal, and eating first is the easiest way to limit the nausea azathioprine can cause in the early weeks. Food does not interfere with how well the medicine is absorbed, so timing around meals is a comfort question rather than a chemical one.
What happens if I miss a dose of azathioprine?
Take the tablet when you notice, unless the next one is nearly due, and then carry on as normal; there is no catching up with a double dose. A steady daily routine matters more than any single late tablet.
Does azathioprine cause hair loss?
Thinning or patchy hair loss is a recognised side effect, because the medicine acts on fast-dividing cells and hair follicles are among them. It tends to appear over the first few months and reverses once the dose is lowered or the medicine is stopped. Nausea and appetite loss often settle sooner.
Does azathioprine make you more prone to infections?
Yes. By damping down the immune response it can make infections more frequent or harder to shake off. A sore throat with fever and chills, or an infection that keeps returning, points to a fall in blood cells and is worth acting on promptly.