Treatment: C. Difficile Infection

• Primary CDI: When feasible, discontinuation of ongoing antimicrobial treatment is an effective cure in 15-23% of cases. Prompt initiation of specific therapy is recommended.
  • - For mild to moderate disease, metronidazole (500 mg tid for 10 days) is recommended, with extension of therapy if the clinical response is slow.
  • - For severe disease (e.g., >15,000 WBCs/µL, serum creatinine levels ≥1.5 times baseline), vancomycin (125 mg qid PO for 10-14 d) is the agent of choice. Fidaxomicin is an alternative and results in lower rates of recurrent disease.
• Recurrent CDI: The first recurrence should be treated the same as the initial episode.
  • - For the second recurrence, an extended, tapered vancomycin regimen (125 mg qid for 10-14 d, then bid for 1 week, then daily for 1 week, then q2-3d for 2-8 weeks) should be used.
  • - For multiple recurrences, there is no standard treatment course. Consider repetition of the tapered vancomycin regimen, administration of vancomycin (500 mg qid for 10 days) with Saccharomyces boulardii (500 mg bid for 28 d), administration of sequential therapy with vancomycin (125 mg qid for 10-14 d) followed by rifaximin (400 mg bid for 2 weeks), treatment with nitazoxanide (500 mg bid for 10 d), or treatment with IV immunoglobulin (400 mg/kg). On the basis of recent successful clinical trials, fecal transplantation is increasingly being used for recurrent CDI.
• Fulminant CDI: Medical management is complicated by ineffective delivery of oral antibiotics to the intestinal lumen in the setting of ileus. Vancomycin (given via nasogastric tube and by retention enema) combined with IV metronidazole has been used with some success, as has IV tigecycline. Surgical colectomy can be life-saving.

For a more detailed discussion, see LaRocque RC, Ryan ET, Calderwood SB: Acute Infectious Diarrheal Diseases and Bacterial Food Poisoning, Chap. 160, p. 852; Gerding DN, Johnson S: Clostridium difficile Infection, Including Pseudomembranous Colitis, Chap. 161, p. 857; Russo TA, Johnson JR: Diseases Caused by Gram-Negative Enteric Bacilli, Chap. 186, p. 1025; Pegues DA, Miller SI: Salmonellosis, Chap. 190, p. 1049; Sansonetti PJ, Bergounioux J: Shigellosis, Chap. 191, p. 1055; Blaser MJ: Infections Due to Campylobacter and Related Organisms, Chap. 192, p. 1058; Waldor MK, Ryan ET: Cholera and Other Vibrioses, Chap. 193, p. 1061; Prentice MB: Plague and Other Yersinia Infections, Chap. 196, p. 1070; Parashar UD, Glass RI: Viral Gastroenteritis, Chap. 227, p. 1285; Andrade M, Reed SL: Amebiasis and Infection with Free-Living Amebas, Chap. 247, p. 1363; and Weller PF: Protozoal Intestinal Infections and Trichomoniasis, Chap. 254, p. 1405, in HPIM-19.