Table 23Summary of trials assessing the comparative harms of constipation drugs

Author, yearStudy designN; Study durationComparisonsPopulation, % female, settingResultsQuality rating
LACTULOSE VS. PEG 3350
Attar et al., 199943RCT, single- blind, open-label115, 4 weeksLactulose vs. PEG 3350French and Scottish patients with chronic constipation, 82% female, general and geriatric hospitalsNo significant differences in median daily scores for diarrhea, abdominal pain, flatulence, or bloating. Fewer days with flatulence in the PEG group (3.8 vs. 9.2; P = 0.01) and a trend toward fewer with abdominal pain (3.9 vs. 6.8; P = 0.08). Mean number of liquid stools was higher in the PEG group (2.4 vs. 0.6; P = 0.001)Poor (No ITT analysis)
LACTULOSE VS. PSYLLIUM
Dettmar, 199865RCT, open-label394, 4 weeksPsyllium vs. lactulose vs. other laxativesAdults with constipation, 63% female, Multi-site, outpatient, UKDiarrhea (1.5% of days vs. 2.2% of days vs. 4.4% of days; P NR) and abdominal pain or griping during weeks 3 to 4 (15.1% vs. 22.0% vs. 29.5%; P NR) were numerically lower in the psyllium group.Poor (No ITT analysis, no blinding, AEs not prespecif ied or defined)
Rouse et al., 199166RCT, open-label124, 4 weeksPsyllium vs. lactuloseAdults with chronic constipation, % female NR, multi-site, outpatient UKNo significant differences for abdominal pain or for straining (P NR). Palatability: At 7 days 18.5% said psyllium was unpalatable vs. 5.7% for lactulose (P = 0.04); at 28 days 15.6% vs. 4.2% (P = 0.063)Poor (High attrition)
PEG 3350 VS. PSYLLIUM
Wang et al., 200545RCT, open-label126, 2 weeksPEG 3350 vs. psylliumChinese patients with chronic constipation, 60% female, multicenter, outpatientNo significant differences in adverse eventsPoor for AEs (Fair for efficacy)

AE: adverse events; ITT: intent-to-treat; NR: not reported; PEG: polyethylene glycol; RCT: randomized controlled trial; UK: United Kingdom

From: Results

Cover of Drug Class Review: Constipation Drugs
Drug Class Review: Constipation Drugs: Final Report [Internet].
Gartlehner G, Jonas DE, Morgan LC, et al.
Portland (OR): Oregon Health & Science University; 2007 Sep.
Copyright © 2007, Oregon Health & Science University, Portland, Oregon.

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