Drug-induced hypochlorhydria causes high duodenal bacterial counts in the elderly.
BACKGROUND
Small bowel bacterial overgrowth secondary to drug-induced hypochlorhydria may be of particular importance in the elderly, in whom anti-ulcer drugs are commonly prescribed and the consequences of malabsorption may be severe.


METHODS
Duodenal aspirates were obtained from elderly individuals before (n = 24) and during a 2-month treatment course with either omeprazole (20 mg daily; n = 8) or ranitidine (300 mg b.d.; n = 6), and from six patients with small bowel bacterial overgrowth who had diarrhoea and malabsorption.


RESULTS
Before treatment, duodenal bacterial counts were normal (< 10(4) colony forming units/mL) in 23 elderly subjects (96%). However, six of 14 patients (43%) treated with omeprazole (5 of 8) or ranitidine (1 of 6) developed bacterial counts > 10(5) cfu/mL. All remained asymptomatic and had normal lactulose breath H2 profiles during treatment.


CONCLUSIONS
Drug-induced hypochlorhydria causes high duodenal bacterial counts in the elderly but, in the short term, this bacterial overgrowth is not associated with malabsorption.
Pereira
S P
SP
Gastroenterology Unit, Guy's Hospital Campus, Division of Medicine, UMDS, London, UK.
Gainsborough
N
N
Dowling
R H
RH
D000126:Achlorhydria / Q000139:chemically induced* / Q000503:physiopathology; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D001420:Bacteria, Aerobic / Q000187:drug effects / Q000254:growth & development*; D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000254:growth & development*; D015169:Colony Count, Microbial; D004386:Duodenum / Q000382:microbiology* / Q000473:pathology; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D011899:Ranitidine / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use
D000897:Anti-Ulcer Agents; D011899:Ranitidine; D009853:Omeprazole