title: Comparison of polyethylene glycol with and without electrolytes in the treatment of constipation in elderly institutionalized patients: a randomized, double-blind, parallel-group study.
abstract: BACKGROUND
  Polyethylene glycol (PEG) is a commonly used osmotic laxative. PEG with electrolytes is mixed with water, but PEG without electrolytes can also be mixed with, for example, juice, coffee or tea, making it more palatable. Laxatives, including PEG, are commonly used by the elderly, particularly those living in institutions. Few clinical studies, however, have investigated the use of PEG in this population.
  
  
  OBJECTIVE
  To test whether PEG 4000 without electrolytes (hypotonic PEG) is at least as effective and safe as PEG 4000 with electrolytes (isotonic PEG) in elderly institutionalized constipated patients. The acceptability of the treatments was also compared.
  
  
  METHODS
  This randomized, double-blind, parallel-group study was conducted at ten private assisted-living facilities or communal nursing homes in Finland. Eligible patients were required to have used isotonic PEG at a stable dose without any other treatment for constipation (except for Plantago ovata seeds) for at least 2 weeks prior to a run-in period. After the 1-week run-in, 62 patients (mean age 86 years; range 66-99 years) were randomly either switched to receive hypotonic PEG or continued to receive isotonic PEG, both dissolved in water, 12 g once or twice daily or once every other day, for 4 weeks. Stool frequency, stool consistency, stool straining and gastrointestinal symptoms were recorded. Safety laboratory tests were conducted before and after the treatment period. Acceptability was assessed at the end of the study.
  
  
  RESULTS
  At week 4, mean (SD) weekly stool frequencies in the hypotonic and isotonic PEG groups were 8.5 (4.5) and 8.4 (3.6), respectively. The mean stool frequency ratio (95% CI) was 0.90 (0.74, 1.10); thus, the PEG products were considered equally effective. At week 4, the proportion of patients with soft or normal stool consistency was higher in the hypotonic PEG group than in the isotonic PEG group (70% vs 52%), but this difference was not statistically significant. There were no differences between the groups in stool straining or gastrointestinal symptoms. In the safety laboratory tests, no clinically significant differences between the groups were detected, although plasma sodium level was statistically significantly lower in the hypotonic PEG group at the end of the study (137.7 vs 138.9 mmol/L, respectively; p = 0.012). Most patients were willing to continue their study treatment (85% in the hypotonic PEG and 63% in the isotonic PEG group; p = 0.070). Compared with only 12% of the patients receiving hypotonic PEG, however, 31% of the patients in the isotonic PEG group rated the taste of the study treatment as bad or very bad (p = 0.101).
  
  
  CONCLUSIONS
  Hypotonic PEG solution is as effective as isotonic PEG in the treatment of constipation in elderly institutionalized patients. Both treatments appear safe, well tolerated and, when dissolved in water, well accepted by the majority of the patients. When desired, switching from isotonic to hypotonic PEG can safely take place in elderly individuals without compromising efficacy.
authors.affiliation: Pirkanmaan Erikoislääkäripalvelu, Tampere, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Seinelä
authors.forename: Ulla
authors.initials: U
authors.lastname: Sairanen
authors.forename: Tarmo
authors.initials: T
authors.lastname: Laine
authors.forename: Sangita
authors.initials: S
authors.lastname: Kurl
authors.forename: Tiina
authors.initials: T
authors.lastname: Pettersson
authors.forename: Pertti
authors.initials: P
authors.lastname: Happonen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003248:Constipation / Q000188:drug therapy* / Q000628:therapy; D004311:Double-Blind Method; D004361:Drug Tolerance; D004573:Electrolytes / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D010342:Patient Acceptance of Health Care; D011092:Polyethylene Glycols / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology / Q000627:therapeutic use*; D012112:Residential Facilities; D016896:Treatment Outcome
chemical_list: D004573:Electrolytes; D011092:Polyethylene Glycols
references.citation: South Med J. 2001 May;94(5):478-81
references.pmid: 11372795
references.citation: J Gastrointestin Liver Dis. 2007 Dec;16(4):379-81
references.pmid: 18193118
references.citation: Eur J Pediatr. 2009 Jul;168(7):851-7
references.pmid: 18958497
references.citation: Gut. 2000 Apr;46(4):522-6
references.pmid: 10716682
references.citation: Aliment Pharmacol Ther. 2007 Mar 15;25(6):703-8
references.pmid: 17311603
references.citation: J Am Geriatr Soc. 1994 Sep;42(9):947-52
references.pmid: 8064102
references.citation: J Am Med Dir Assoc. 2001 Jul-Aug;2(4):149-54
references.pmid: 12812571
references.citation: J Gerontol A Biol Sci Med Sci. 2001 Apr;56(4):M200-5
references.pmid: 11283191
references.citation: Aliment Pharmacol Ther. 2003 Jan;17(1):165-72
references.pmid: 12492746
references.citation: Am J Gastroenterol. 2007 Jul;102(7):1436-41
references.pmid: 17403074
references.citation: Drugs Aging. 2008;25(10):807-21
references.pmid: 18808206
references.citation: Arch Pediatr Adolesc Med. 2003 Jul;157(7):661-4
references.pmid: 12860787
references.citation: Arch Fam Med. 1993 Aug;2(8):853-8
references.pmid: 8111515
references.citation: Am J Gastroenterol. 1996 Jan;91(1):19-25
references.pmid: 8561137
references.citation: Arch Intern Med. 1993 Mar 8;153(5):633-8
references.pmid: 8439226
references.citation: Dig Dis Sci. 1996 Aug;41(8):1636-42
references.pmid: 8769292
references.citation: Am J Gastroenterol. 2005 Apr;100(4):936-71
references.pmid: 15784043
references.citation: South Med J. 2007 Nov;100(11):1085-90
references.pmid: 17984738
references.citation: Drugs Aging. 2007;24(2):147-54
references.pmid: 17313202
references.citation: Gut. 1999 Feb;44(2):226-30
references.pmid: 9895382
references.citation: Am J Gastroenterol. 2000 Feb;95(2):446-50
references.pmid: 10685748
references.citation: J Pediatr. 2001 Sep;139(3):428-32
references.pmid: 11562624
references.citation: Pediatr Infect Dis J. 1996 Sep;15(9 Suppl):S30-7
references.pmid: 8878244