Eosinophilia (drug induced)

• drugs that may cause raised eosinophil count include (1,2,3,4):
  
  
  • antimicrobials
    • such as penicillins, cephalosporins, nitrofurantoin, tetracyclines, daptomycin, fluoroquinolones
      
      
  • sulphonamides
    • such as sulfasalazine, septrin, dapsone
      
      
  • ranitidine
    
    
  • allopurinol
    
    
  • angiotensin converting enzyme (ACE) inhibitors
    
    
  • anticonvulsants
    • such as phenytoin, carbamazepine, lamotrigine
      
      
  • antiretrovirals
    • nevirapine, abacavir
      
      
  • non-steroidal anti-inflammatory drugs (NSAIDs)
    
    
  • methotrexate
    
    
  • interleukin-2 (IL-2)

Factors such as intercurrent steroid treatment and bacterial or viral infection can transiently lower eosinophil counts (4)

Reference:

• Felig P et al (2001) Endocrinology and Metabolism. McGraw-Hill.
• Hart FD (Ed) (2005). French's Index of Differential Diagnosis.
• NHS Camden CCG. Abnormal FBC guidance - for adults (Accessed 30/10/19)
• Thakker C, Booth H L, Lambert J, Morgan S, Checkley A M. Investigating eosinophilia BMJ 2023; 380 :e070295 doi:10.1136/bmj-2022-070295