A recent letter (FE Juul et al. NEJM 2018; 378: 2535-6) describes the results of a small study in which fecal microbiota transplantation (FMT) (n=9) was compared with metronidazole (n=11) for primary treatment of Clostridium dificille infection. The primary end point was clinical cure (firm stool consistency ≤3 BMs/day) and no evidence of recurrent C diff infeciton.
In C diff group, 5 had full primary response and an additional 3 had full response after additional antibiotics which were added in in three of the four without primary response by day 4. By day 70, 7 of 9 (78%) had full response.
In metronidazole group, five had full primary response. By day 70, only five of eleven (45%) had full response.
My take: It would probably be better to compare FMT to either vancomycin of fidaxomin (rather than metronidazole) for primary treatment. Until more data are available, this study does not change clinical practice of using antimicrobials for C diff as primary treatment.
An interesting image (D Farmakiotis, B Zeluff. NEJM 2016; 374: 1465) shows an unusual side effect from metronidazole. This individual who had cirrhosis presented with confusion after a fall.
The MRIs below show “a symmetric, enhanced fluid-attenuated inversion recovery (FLAIR) signal in the dentate nuclei of the cerebellum (Panel A, arrow), a finding consistent with encephalopathy associated with metronidazole use.” Panel B shows resolution one month later following metronidazole discontinuation.
Risk factors for metronidazole encephalopathy:
Prolonged treatment with metronidazole (typical cumulative dose >20 g)
The first publication reviews acid suppression and the risk of C difficile infection (CDI). It starts off with a terrific piece of advice from Sir William Osler: “One of the first duties of the physician is to educate the masses not to take medicine.” The authors note that pH above 4 has been shown to increase bacterial survival, including C perfringe spores in a mouse model. In addition, the article notes that there have been concerns as early as 1982 that acid suppression could be a risk factor for CDI. Several recent studies were summarized, including the following:
A recent meta-analysis (Kwok CS et al. Am J Gastroenterol 2012; 107: 1011-9) with 42 studies (N= 313,000 patients) “found an association between PPI use and risk of CDI (OR1.74, 05%CI 1.47-2.85).”
A review of the literature (Deshpande A et. Clin Gastroenterol Hepatol 2012; 10: 225-33) between 1990-2010 found an overall increase in CDI risk with PPIs to be OR 2.15 (95% CI 1.81-2.55). No prospective studies were identified.
In pediatrics, a study (Turco et al. Alimentary Pharmacol Therapeut 2010; 31: 754-9) with 910 children admitted for abdominal pain and diarrhea identified 68 with CDI. Compared with control patients, use of PPIs was significantly higher in CDI patients (OR 4.52, 95% CI 1.4-14.4).
The FDA has stated that PPIs may be associated with an increased risk of CDI. In addition, the use of antibiotics “appear to act synergistically with PPIs.” Thus, the authors recommend stopping PPIs in those who do not need them. Periodic ‘holidays’ or dosing step-downs may help assess continued need for PPIs.
The second publication succinctly reviews the diagnosis and management of CDI. The various diagnostic methods are compared in Table 1. Therapeutic options for 1st time infection are reviewed in Table 2. For adults with mild-to-moderate infections, metronidazole (500 mg TID for 10 days) is preferred. Vancomycin or Fidaxomicin are recommended for more severe infections.
Table 3 lists treatment options for recurrent CDI. Repeat course of any of the 1st round treatments can be considered depending on patient’s illness severity. In addition, other potential treatments included the following:
vancomycin tapered dose (week 1: 125 mg 4 times/day, week 2: 125 mg 2 times/day, week 3: 125 mg once/day, week 4: 125 mg every other day, week 5 & 6: 125 mg every third day)
rifaximin (550 mg BID x 20 days)
high-dose vancomycin (250-500 mg 4 times/day for 10 days) followed by S boulardii (2 capsules BID for 28 d)
fecal microbiota transfer (FMT) –“although family member stool donors have been used, the current movement is toward volunteer donor pools.” [I do not think ‘current movement’ was intended as a pun by the authors.] Volunteer donors could lower the screening costs.
intravenous immunoglobulin (small clinical trials have failed to show efficacy)
While the development of antibacterial resistance has broad implications, in gastroenterology patients specific problems have emerged with Helicobacter pylori (H pylori) and this has led to changes in first-line therapy( ). More data on the treatment resistant H pylori has been published (JPGN 2013; 56: 645-48).
77 consecutive strains of H pylori from Brazilian children and adolescents were isolated from gastric biopsies and analyzed; this study took place between 2008-2009 and the mean age was 11.1 years. In 71 strains, there were no previous attempts at eradication.
40% of strains were resistant to metronidazole
19.5% of strains were resistant to clarithromycin
10.4% of strains were resistant to amoxicillin
All strains were susceptible to furazolidone and tetracycline
14/77 (18.2%) patients had multiple resistances
Take-home point: Resistance to antibiotics is altering our approach to H pylori therapy. Antibiotic susceptibility testing may be needed to improve antibiotic selection and eradication rates.
Though I have not seen much in the way of neurological complications in our pediatric inflammatory bowel disease (IBD) population, nevertheless I worry about them. A recent article provides some insight into the incidence, the pathophysiology and approach to these complications (Inflamm Bowel Dis 2013; 19: 864-72).
Types of neurologic complications: The most common neurologic complication is peripheral neuropathy. The frequency is quite variable based on data collection method. In large administrative healthcare data, the prevalence has been reported around 2% whereas in cohort studies the range has been 8-15%. Other complications include meylopathy, cerbrovascular disease, cranial nerve palsy (eg. Melkersson-Rosenthal syndrome), seizures, and demyelinating diseases.
With regard to demyelinating diseases, this has gained additional attention in the setting of biologic agents which have been associated with this complication. However, the authors note that a pre-biologic treatment study from Olmstead County, observed a prevalence of multiple sclerosis of 1% which was 3.7 times higher than expected. In addition, similar studies have confirmed this finding.
Potential mechanisms vary greatly depending on the neurologic complication. With regard to cerebrovascular disorders, “venous thromboembolism (VTE) has been shown to occur 3 times more frequently in patients with IBD (the risk increases to 8-10-fold in patients with active colitis) than the general population.” Hence, VTE prophylaxis is recommended by the authors in hospitalized IBD patients, especially if they are experiencing a disease exacerbation.
In addition to the underlying disease, vitamin deficiencies (eg. Vitamin B12) and medications can trigger neurologic complications.
Helicobacter pylori (H pylori) infections remain an important cause of gastritis, ulcers, and adenocarcinoma of the stomach. One new approach in treatment has been the use of sequential therapy. More data is now available on the effectiveness of this approach and choice of antibiotics (Gastroenterology 2012; 143: 55-61 & editorial 10-12).
In the study, a 10-day sequential regimen (SR) was compared with a 5-day concomitant regimen (CR).
SR group (n-90): esomeprazole 40 mg BID, amoxicillin 1 g BID for 5 days, then esomeprazole 40 mg BID, levofloxacin 500 mg BID, tinidazole 500 mg BID for 5 days. Eradication rate (intention-to-treat): 93%
Both groups had good results in part due to low resistance rates
Useful advice on this study from the editorial:
‘We prefer concomitant therapy because it is not complex and it may retain its effectiveness at a slightly higher level of resistance compared with sequential therapy.” Authors prefer 4-drug non-bismuth-containing concomitant treatment.
With bismuth therapy (eg. bismuth-metronidazole-tetracycline-PPI), authors prefer a 14 day course. 10-day treatment may be effective when metronidazole resistance is considered unlikely.
“Clarithromycin should be abandoned as an empiric regimen” due to resistance in U.S.
Fluoroquinolone resistance is increasing rapidly and “prior use virtually ensures resistance.” Suggested use of fluoroquinolone therapy among adults would be as a rescue therapy (failed 2 different therapies), using dosing regimen as noted in cited study, and in patient without history of prior fluoroquinolone use (&/or proof on susceptibility testing)
Recommendations for first line treatment are a triple-based therapy with PPI and two antibiotics (eg. amoxicillin and metronidazole). Alternatives, include bismuth plus two antibiotics, or sequential therapy. Use of clarithromycin is recommended only after susceptibility testing.
-Gut 2010; 59: 1143-53. Changing treatment recommendations for Helicobacter pylori in the face of resistance.
-Am J Gastroenterol 2007; 102: 1808-1825. American College of Gastroenterology Guideline on the Management of Helicobacter pylori Infection. Doxycycline can be used in place of tetracycline
-Gastroenterol 2007; 133: 985. Review. Good article for resistant infections.
-Gastroenterol 2005; 129:1414-19. Sequential Rx (amox + PPI x 5 days, then biaxin, tinidazole, PPI for 5 days) had 97% success.