Background: Drug induced hemolytic anemia and thrombocytopenia (DIHA and DIT) are common drug adverse effects of antibiotics in patients admitted to hospital.  This reaction is important in patients who have a chronic disease especially in pediatrics. In this study, possible hemolytic anemia was investigated before and after the antibiotics administration.
Materials and Methods: A total of 835 children were investigated in this retrospective study. The laboratory tests were performed before and at least one week after antibiotics administration. The red blood cell (RBC), platelet (plt), hematocrit (Hct), and hemoglobin (Hb) were measured.
Results: With respect to age, 76.11% of studied patients were under 6 years old. The others were between 6-10 years (mean 5.38 years). The two tailed T tests results on the patients’ information showed  a difference between RBC, platelet, hematocrit, and hemoglobin values before and after antibiotics administration to the point where the RBC mean counts before and after administration were 4.53 to 3.82 *1012/L, respectively. These changes for plt, Hb, and Hct were 323.5 to 232.5 *109/L, 13.61 to 11.46 mg/dL, and 40.83 to 34.38 %, respectively. The p-values were 0.000025, 0.000051, 0.000061, and 0.000032 for RBC, platelet, hematocrit, and hemoglobin; respectively. This finding confirmed that antibiotics administration can decrease the platelets and RBC count. The antibiotics used in the children were ceftriaxone (38.2%), clindamycin (23.3%), Clarithromycin (19.6%), and acyclovir (12.1%); respectively. The dose of the ceftriaxone varied from 50 mg/kg to 70 mg/kg in shigelloses and pneumonia, respectively. Additionally, clindamycin, clarithromycin, and acyclovir were prescribed for 10 mg/kg, 5-10, and 10 mg/kg per day; respectively.
Conclusion: This study showed that antibiotics administration had adverse effects and should be considered when they are prescribed to children with chronic diseases. The physicians should be awarded about proper dosing to decrease adverse effects.