Download Therapeutics – Drug Induced Blood Disorders

Drug Induced Haematologic Disorders
Aplastic anemia (Pancytopenia) : The drugs which cause one marrow aplasia include
alkylating agents, antimetabolites, antibiotics, vinca alkaloids.The antibacterial drug,
chloramphenicol phenybutazone, oxyphenbutazone and indomethacin are the most common
causes of aplastic anemia.Chloramphenicol causes the bone marrow toxicity in two ways.One is
bu inhibiting the mitochoncrial protein synthesis and the other type is much serious causing true
bone marrow aplasis which cannot be prevented by chloramphenicol withdtawl.
Agranulocytosis: It is another drug induced condition due to destruction of granulocytic
leucocytes by the antibodies. This condition may happen due to toxic depression of bone marrow
/stem cells after prolonged administration of drug inlarge dose. Drugs which induce
agranulocysis include sulfonamides,sulfonylureas, phenothiazines antithydroid drugs, phenyl
butazone and semisynthetic penicillins, antitubercular drugs.
Thrombocytopenia: The reduction in the count of thrombocytes (Plarelets) is due to the bone
marrow suppression and the destruction of platelets.The cytotoxicdrugs chloramphenicol,
sulphanomides, phenothiazines, antiepileptics causes the bone marrow suppression.The drugs
which form the immune complexes that destroy platelets are quinine, quindine, aspirin,
methyldopa, cardiotonics acetazolamide.
Haemolytic anemia :
The haemolytic anemia may occur due to genetic abnormality or acquiredimmunogical
abnormality
Haemolysis
occurs
in
patients
with
deficiency
ofglucose-6-phosphate
dehydrogenase.The immune haemolytic reaction takes placewith methyldopa, levodopa and
mefenamic acid and streptomycin.These drugs bind to the proteins in the R.B.C. and causes
haemolysis.