| Azathioprine Pharmacology |
| Azathioprine |
| About Azathioprine |
| N/A |
| Mechanism of Action of Azathioprine |
| Drug causes a greater suppression of delayed hypersensitivity and cellular cytotoxicity. Drug also antagonizes purine metabolism (necessary for proliferation of cells especially for leukocytes and lymphocytes) and may inhibit the synthesis of DNA, RNA and proteins. It may also inhibit the cellular metabolism and inhibit mitosis. |
| Pharmacokinets of Azathioprine |
| Absorption – Well absorbed after oral administration Distribution- Drug and its active metabolite widely distributed in the body.30% bound to the plasma proteins. Drug and its active metabolite cross the placental barrier. Metabolism- Metabolized to its active forms in the blood and then to inactive form in liver (by xanthine Oxydase enzyme) and erythrocytes .Mercaptopurine and 6-thioinosinic acid is its active metabolites. Excretion- It is excreted through urine (as parent form and metabolites) and bile. |
| Onset of Action for Azathioprine |
| 4-8 weeks |
| Duration of Action for Azathioprine |
| N/A |
| Half Life of Azathioprine |
| Its plasma half life is 5 hours |
| Side Effects of Azathioprine |
| 1. Nausea 2. Vomiting 3. lowered resistance to infection 4. Bruising or unusual bleeding 5. Anemia 6. Weakness 7. sore in mouth 8. Taste changes 9. Diarrhea 10. Loss of appetite 11. Visual changes 12. Black, tarry stools 13. Blood in urine or in stool 14. Cough or hoarseness 15. Fever 16. Chills 17. Lower back or side pain 18. Painful or difficult urination 19. Pinpoint red spot on skin 20. Slurred speech 21. Swelling on leg or lower leg 22. Shortness of breath 23. Bloody vomiting 24. Thinned or brittle hair 25. Mouth blistering 26. Thrombocytopenia 27. Leucopenia 28. Coma 29. Seizures 30. Pancytopenia 31. Agranulocytosis 32. Aplastic anemia 33. Myalgia 34. Hypocalcaemia 35. Alopecia |
| Contra-indications of Azathioprine |
| Contraindicated in patients with hypersensitivity to the drug or its ingredients |
| Special Precautions while taking Azathioprine |
| 1. Renal impairment 2. Hepatic dysfunction |
| Pregnancy Related Information |
| Contraindicated. |
| Old Age Related Information |
| Use with caution. |
| Breast Feeding Related Information |
| Contraindicated. |
| Children Related Information |
| Use with caution. |
| Indications for Azathioprine |
| 1. Ulcerative colitis 2. To prevent rejection of kidney transplants 3. Rheumatoid arthritis 4. Crohn`s disease 5. Cirrhosis 6. Dermatomyositis 7. Hepatitis C 8. Lupus erythematosus 9. Myasthenia gravis 10. Myopathy 11. Nephritic syndrome 12. Pemphigoid 13. Pemphigus 14. Atopic dermatitis 15. Cutaneous polyarteritis nodosa 16. Cutaneous vasculitis 17. Immune mediated hemolytic anemia 18. Immune mediated platelet destruction |
| Interactions for Azathioprine |
| N/A |
| Typical Dosage for Azathioprine |
| Oral- Adult- To prevent rejection of kidney transplants: 3-5mg/kg/day beginning on 1st day to 3rd days before transplantation. Maintenance dose is 1-3mg/kg/day Children- Same as adult Rheumatoid arthritis Adults- 1mg/kg as a single dose or in divided doses- |
| Schedule of Azathioprine |
| H |
| Storage Requirements for Azathioprine |
| Stored in a tightly closed container at room temperature. Protect from light and excessive heat. Keep out of reach of children |
| Effects of Missed Dosage of Azathioprine |
| Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose. |
| Effects of Overdose of Azathioprine |
| Give symptomatic and supportive treatment. If needed treated with blood products |