Try to avoid close contact with people who have chickenpox infections. Azathioprine and mercaptopurine affect the way your immune system functions, which can make you more prone to infections. Also, even mild infections, such as a cold or sore throat, may develop into a more serious illness. Contact your doctor if you begin to feel unwell or think you may have caught an infection
You may also be more likely to become seriously ill from chickenpox, shingles, measles and pneumonia. If you have not already been vaccinated against these infections, it could be a good idea to do so before starting treatment with azathioprine or mercaptopurine. Otherwise, tell your doctor or nurse as soon as possible if you come into contact with anyone who has any of these conditions, as you may be able to have protective treatment against some of the infections
Avoid driving and hazardous work until you have learned how azathioprine or mercaptopurine affects you, as these drugs can occasionally cause dizziness
Have regular cervical smears. Research suggests women taking immunosuppressive drugs have increased cervical abnormalities and higher risks of these abnormalities progressing to cervical cancer. Some experts recommend that women who have weakened immune systems should be tested twice during the first year of diagnosis and annually thereafter
Azathioprine and mercaptopurine increase the skin’s sensitivity to sunlight and the risk of developing some forms of skin cancer. Use sunblock and wear a hat and cover your skin when out in strong sunshine. Do not use sunlamps or sun beds
Avoid taking mercaptopurine tablets at the same time as you drink milk. Cow’s milk is known to contain high levels of xanthine oxidase, a chemical that inactivates mercaptopurine
Consider carrying or wearing medical alert identification to show you are taking azathioprine or mercaptopurine