Main indications in lupus

- Severe forms of lupus, in patients who are intolerant to steroids or steroid-dependent or whose therapeutic response is insufficient despite treatment using high doses of steroids

- Associated autoimmune hepatitis

- Some autoimmune cytopenias (decreased quantity of blood cells in the bloodstream)

Dosage

- Tablets of 25 and 50 mg

- From 2 to 3 mg / kg / day in 1 to 3 doses, at

meal times

Key Drug Interactions

- Allopurinol increases the toxicity of azathioprine

Main side effects

- Haematological involvement affecting the 3 lines (red blood cells, white blood cells and platelets)

- Pneumonitis (pulmonary involvement) of sometimes severe hypersensitivity (hyperthermia, hypotension, oliguria, rash)

- Abdominal pain, nausea

- Hepatitis (damage to the liver)

- Pancreatitis (damage to the pancreas)

Contraindications

- Hypersensitivity

- Severe haematological abnormalities

- Ongoing infection (temporary discontinuation of treatment)

- Breastfeeding

Precautions for use

- Pregnancy is not a contraindication, azathioprine is one of the few immunosuppressants that can be maintained during pregnancy

- Determination of the enzyme, thiopurine methyltransferase (TPMT) that metabolizes the drug. This assay makes it possible to detect subjects who are at risk of toxicity of azathioprine

- Dose reduction if leukopenia <2 500/mm3 or thrombocytopenia <130 000/mm3

- Skin monitoring and consultation if an abnormal pimple appears persisting for more than 3 weeks

- Dose adjustment in case of renal or hepatic failure

Monitoring

- Blood count, liver and pancreatic assessment: 1/week for 2 months, then 1/15 days for 1 month, and then 1/month

- Clinical monitoring