Vaccines: Vaccinations with live organism vaccines are not recommended in immunocompromised individuals (see Precautions).
Other myelotoxic substances or radiation therapy: During concomitant administration of other myelotoxic substances or radiation therapy, the risk of myelosuppression is increased.
Allopurinol: The concomitant use of allopurinol to inhibit uric acid formation does not necessitate reduction of dosage of LANVIS as is necessary with mercaptopurine and azathioprine.
Aminosalicylate derivatives: As there is in vitro evidence that aminosalicylate derivatives (e.g. olsalazine, meslazine or sulphasalazine) inhibit the TPMT enzyme, they should be administered with caution to patients receiving concurrent LANVIS therapy (see Precautions).