Table 7Summary of trials assessing the general efficacy of drugs for the treatment of chronic constipation in adults

Author, yearStudy designN; Study durationComparisonsPopulation, % female, settingResultsQuality rating
PEG 3350
Andorsky et al., 199032RCT, cross-over37; 5 daysPlaceboPatients with chronic constipation, 76% female, setting NRStatistically significantly higher mean stool frequency/week with PEG (7.75 vs. 4.88; P < 0.01)Fair
Cleveland et al., 200133RCT, cross-over23, 2 weeksPlaceboPatients with chronic constipation, 96% female, from GI- practices and primary care practiceStatistically significantly higher mean stool frequency/week with PEG (7.0 vs. 3.6; P = 0.001)Poor (high attrition, no ITT analysis)
DiPalma et al., 200031RCT151; 2 weeksPEG 3350 (17g/d) vs. placeboPatients with chronic constipation, 87% female, from GI- practicesStatistically significantly more with treatment success with PEG (66% vs. 48%; P < 0.005)Fair
Ashraf et al., 199536RCT22, 8 weeksPsyllium (10g/d) vs. placeboPatients with chronic constipation, 64% female, tertiary careStatistically significant increase in stool frequency (3.8 vs. 2.9; P < 0.05)Fair
Fenn et al., 198635RCT, single-blinded201; 2 weeksPsyllium (10.8g/d) vs. placeboBritish primary care population, 75% femaleStatistically significant reduction in abdominal pain (P = 0.035) and straining (P = 0.003) for psylliumPoor (no ITT analysis)

GI: gastrointestinal; ITT: intent-to-treat; NR: not reported; PEG: polyethylene glycol; RCT: randomized controlled trial

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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