Q: What is the appropriate dose of oral vancomycin in C.diff. associated diarrhea  (CDAD)?


Answer:  125 mg four times daily

Though popular dose is 500 mg four times daily, but studies fail to show any superiority of higher dose.



References: 

1. Fekety R, Silva J, Kauffman C, et al. Treatment of antibiotic-associated Clostridium difficile colitis with oral vancomycin: comparison of two dosage regimens. Am J Med 1989; 86:15. 

2. Cohen SH, Gerding DN, Johnson S, et al. Clinical practice guidelines for Clostridium difficile infection in adults: 2010 update by the society for healthcare epidemiology of America (SHEA) and the infectious diseases society of America (IDSA). Infect Control Hosp Epidemiol 2010; 31:431.