Adverse effects of drugs on the blood

Abstract

Amongst adverse drug reactions blood dyscrasias are not frequent, but they may have serious consequences. Compared with Sweden, data from The Netherlands are scarce. It is to be expected that regular reports about the incidence of drug-induced blood dyscrasias may play an important role in general prevention. Blood dyscrasias may be caused by a variety of drugs, from many pharmacotherapeutic groups with diverse chemical structures and with all application forms. Metabolism and distribution may influence the activity of drugs. Drug-induced anaemias, including aplastic anaemia, are briefly discussed. Toxic and immune mechanisms may occur. The same holds with regard to the leucopenias. Drug-induced thrombocytopenia is mainly immune-mediated (cytostatics being excluded as causative agents). In immune-mediated drug-induced blood dyscrasias often haptens must be formed. They can be formed in vivo in the liver or in the lymphocytes. In some cases they appear to be formed even in vitro. Tracing the causative agent of a dyscrasia, be it a drug or some other substance, requires a series of investigations, comprising usage of the drug, serology and cell culture. Provocation tests are seldom justified. Distinct preventive measures can be taken to minimize the risk of blood dyscrasias: avoidance of risky drugs, awareness of the patient about early clinical signs and haematological control.

Factors associated with hematological adverse reactions of drugs authorized via the centralized procedure

“…A single cell line (e.g., anemia), multiple cell lines, or all bone marrow cell lines (e.g., pancytopenia) could be affected, leading to varying severity in terms of the patient’s condition, prolonged hospitalization, and potentially death. Although the prevalence of HADRs is expected to increase with the use of chemotherapeutics—which directly block the multiplication of cells with a short lifecycle (e.g., the prevalence of anemia varies between 30 and 85%)—HADRs associated with nonchemotherapeutics are different, as they affect bone marrow cell lines and blood cells themselves through a variety of mechanisms, which have not been sufficiently studied 3 – 7 .…”