Laxatives,purgatives,oraperientsare substances that loosenstools[1]and increasebowel movements.They are used to treat and preventconstipation.
![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/98/Glycerin_suppositories.jpg/220px-Glycerin_suppositories.jpg)
Laxatives vary as to how they work and the side effects they may have. Certainstimulant,lubricant,andsalinelaxatives are used to evacuate thecolonforrectaland bowel examinations, and may be supplemented byenemasunder certain circumstances. Sufficiently high doses of laxatives may causediarrhea.Some laxatives combine more than one active ingredient, and may be administeredorallyorrectally.
Types
editBulk-forming agents
editBulk-forming laxatives, also known asroughage,are substances, such asfiberin food andhydrophilicagents inover-the-counter drugs,that add bulk and water tostoolsso they can pass more easily through theintestines(lower part of thedigestive tract).[2]
Properties
- Site of action:smallandlarge intestines
- Onset of action: 12–72 hours
- Examples: dietary fiber,Metamucil,Citrucel,FiberCon[3]
Bulk-forming agents generally have the gentlest of effects among laxatives,[1]making them ideal for long-term maintenance of regular bowel movements.
Dietary fiber
editFoods that help with laxation include fiber-rich foods.Dietary fiberincludesinsoluble fiberandsoluble fiber,such as:[4]
- Fruits,such asbananas,[5]though this depends on their ripeness,[6]kiwifruits,[7]prunes,[8]apples(with skin),pears(with skin), andraspberries[1]
- Vegetables,such asbroccoli,string beans,kale,spinach,[4]cookedwinter squash,cookedtaroandpoi,cookedpeas,and bakedpotatoes(with skin)[1]
- Whole grains
- Branproducts[1][4]
- Nuts
- Legumes,such asbeans,peas,andlentils[1]
Emollient agents (stool softeners)
editEmollient laxatives, also known as stool softeners, areanionic surfactantsthat enable additional water and fats to be incorporated in the stool, making movement through the bowels easier.
Properties
- Site of action: small and large intestines
- Onset of action: 12–72 hours
- Examples:Docusate(Colace, Diocto), Gibs-Eze[3]
Emollient agents prevent constipation rather than treating long-term constipation.[3]
Lubricant agents
editLubricantlaxatives are substances that coat the stool with slippery lipids and decrease colonic absorption of water so the stool slides through the colon more easily. Lubricant laxatives also increase the weight of stool and decrease intestinal transit time.[9]
Properties
- Site of action: colon
- Onset of action: 6–8 hours
- Example:mineral oil[9]
Mineral oils,such asliquid paraffin,are generally the only nonprescription lubricant laxative available, but due to the risk of lipid pneumonia resulting from accidental aspiration, mineral oil is not recommended, especially in children and infants.[10][11]Mineral oil may decrease the absorption of fat-soluble vitamins and some minerals.[9]
Hyperosmotic agents
editHyperosmoticlaxatives cause the intestines to hold more water, creating anosmotic gradient,which adds more pressure and stimulates bowel movement.[12][10]
Properties
- Site of action: colon
- Onset of action: 12–72 hours (oral), 0.25–1 hour (rectal)
- Examples:glycerinsuppositories (Hallens),sorbitol,lactulose,andpolyethylene glycol(PEG- Colyte, MiraLax)[12]
Lactuloseworks by theosmoticeffect, which retains water in the colon; lowering thepHthrough bacterial fermentation to lactic, formic, and acetic acids; and increasing colonicperistalsis.Lactulose is also indicated inportal-systemic encephalopathy.Glycerin suppositories work mostly by hyperosmotic action, but thesodium stearatein the preparation also causes local irritation to the colon.[citation needed]
Solutions ofpolyethylene glycoland electrolytes (sodium chloride,sodium bicarbonate,potassium chloride,and sometimessodium sulfate) are used forwhole bowel irrigation,a process designed to prepare the bowel for surgery orcolonoscopyand to treat certain types ofpoisoning.Brand names for these solutions include GoLytely, GlycoLax, Cosmocol, CoLyte, Miralax, Movicol, NuLytely, Suprep, and Fortrans. Solutions ofsorbitol(SoftLax) have similar effects.[citation needed]
Saline laxative agents
editSaline laxatives are nonabsorbable, osmotically active substances that attract and retain water in the intestinal lumen, increasing intraluminal pressure that mechanically stimulates evacuation of the bowel. Magnesium-containing agents also cause the release ofcholecystokinin,which increases intestinal motility and fluid secretion.[3]Saline laxatives may alter a patient's fluid and electrolyte balance.
Properties
- Site of action: small and large intestines
- Onset of action: 0.5–3 hours (oral), 2–15 minutes (rectal)
- Examples:sodium phosphate(and variants),magnesium citrate,magnesium hydroxide(milk of magnesia), andmagnesium sulfate(Epsom salt)[3]
Stimulant agents
editStimulant laxatives are substances that act on the intestinalmucosaornerve plexus,altering water andelectrolytesecretion.[13]They also stimulate peristaltic action and can be dangerous under certain circumstances.[14]
Properties
Prolonged use of stimulant laxatives can create drug dependence by damaging the colon'shaustral folds,making users less able to move feces through their colon on their own. A study of patients with chronic constipation found that 28% of chronic stimulant laxative users lost haustral folds over the course of one year, while none of the control group did.[15]
Miscellaneous
editCastor oilis a glyceride that is hydrolyzed by pancreatic lipase toricinoleic acid,which produces laxative action by an unknown mechanism.
Properties
- Site of action: colon, small intestine (see below)[citation needed]
- Onset of action: 2–6 hours
- Examples: castor oil[3]
Long-term use of castor oil may result in loss of fluid, electrolytes, and nutrients.[3]
Serotonin agonist
editThese are motility stimulants that work through activation of5-HT4receptors of theenteric nervous systemin thegastrointestinal tract.However, some have been discontinued or restricted due to potentially harmful cardiovascular side effects.
Tegaserod(brand nameZelnorm) was removed from the general U.S. and Canadian markets in 2007, due to reports of increased risks of heart attack or stroke. It is still available to physicians for patients in emergency situations that are life-threatening or require hospitalization.[16]
Prucalopride(brand name Resolor) is a current drug approved for use in the EU since October 15, 2009,[17]in Canada (brand name Resotran) since December 7, 2011,[18]and in the United States since December 2018.
Chloride channel activators
editLubiprostoneis used in the management of chronic idiopathic constipation and irritable bowel syndrome. It causes the intestines to produce a chloride-rich fluid secretion that softens the stool, increases motility, and promotes spontaneous bowel movements.
Comparison of available agents
editPreparation(s) | Type | Site of action | Onset of action |
---|---|---|---|
Cascara(casanthranol) | Anthraquinone | colon | 6–8 hours |
Buckthorn | Anthraquinone | colon | 6–8 hours |
Senna extract(senna glycoside) | Anthraquinone | colon | 6–8 hours |
Aloe vera(aloin) | Anthraquinone | colon | 8–10 hours |
Phenolphthalein | Triphenylmethane | colon | 8 hours |
Bisacodyl(oral) | Triphenylmethane | colon | 6–12 hours |
Bisacodyl (suppository) | Triphenylmethane | colon | 60 minutes |
Castor oil | Ricinoleic acid | small intestine | 2–6 hours |
Effectiveness
editFor adults, arandomized controlled trialfoundPEG(MiraLax or GlycoLax) 17 grams once per day to be superior totegaserodat 6 mg twice per day.[21]A randomized controlled trial found greater improvement from two sachets (26 g) of PEG versus two sachets (20 g) of lactulose.[22]17 g per day of PEG has been effective and safe in a randomized, controlled trial for six months.[23]Another randomized, controlled trial found no difference between sorbitol and lactulose.[24]
For children, PEG was found to be more effective than lactulose.[25]
Problems with use
editLaxative abuse
editSome of the less significant adverse effects of laxative abuse includedehydration(which causes tremors, weakness, fainting, blurred vision, kidney damage),low blood pressure,fast heart rate,postural dizziness andfainting;[26]however, laxative abuse can lead to potentially fatalacid-base,andelectrolyte imbalances.[26]For example, severehypokalaemiahas been associated withdistal renal tubular acidosisfrom laxative abuse.[26]Metabolic alkalosisis the most common acid-base imbalance observed.[26]Other significant adverse effects includerhabdomyolysis,[26]steatorrhoea,[26]inflammationandulcerationof colonic mucosa,[26]pancreatitis,[26][27]kidney failure,[26][28][29]factitious diarrhea[26][30]and other problems.[26]The colon will need more quantities of laxatives to keep functioning, this will result in a lazy colon, infections, irritable bowel syndrome, and potential liver damage.
Although some patients with eating disorders such asanorexia nervosaandbulimia nervosaabuse laxatives in an attempt to lose weight, laxatives act to speed up the transit of feces through the large intestine, which occurs after the absorption of nutrients in the small intestine is already complete. Thus, studies of laxative abuse have found that effects on body weight reflect primarily temporary losses of body water rather than energy (calorie) loss.[26][31][32]
Laxative gut
editPhysicians warn against the chronic use of stimulant laxatives due to concern that chronic use could cause the colonic tissues to get worn out over time and not be able to expel feces due to long-term overstimulation.[33]A common finding in patients having used stimulant laxatives is a brown pigment deposited in the intestinal tissue, known asmelanosis coli.[citation needed]
Historical and health fraud uses
editLaxatives, once called "physicks" or "purgatives", were used extensively inhistoric medicineto treat many conditions for which they are now generally regarded as ineffective inevidence-based medicine.[34]Likewise, laxatives (often termedcolon cleanses) may be promoted inalternative medicinefor various conditions ofquackery,such as "mucoid plaque".[35]
See also
editReferences
edit- ^abcdef"Constipation"(PDF).www.digestive.niddk.nih.gov.National Digestive Diseases Information Clearinghouse.Retrieved3 November2014.
- ^Bulk-forming agententry in the public domain NCI Dictionary of Cancer Terms
- ^abcdefghBerardi M, Tietze KJ, Shimp LA, Rollins CJ, Popovich NG (2006).Handbook of Nonprescription Drugs(15th ed.). Washington, D.C.: American Pharmaceutical Association.ISBN978-1582120744.
- ^abc"The Facts About Fiber"(PDF).www.aicr.org.American Institute for Cancer Research. Archived fromthe original(PDF)on 3 November 2014.Retrieved3 November2014.
- ^Das, JL (2010)."Medicinal and nutritional values of banana cv. NENDRAN".Asian Journal of Horticulture.8:11–14. Archived fromthe originalon 2014-11-03.Retrieved2012-11-29.
- ^"15 Foods That Cause Constipation (Caffeine, Chocolate, Alcohol)".MedicineNet.Retrieved2017-12-12.
- ^Rush EC, Patel M, Plank LD, Ferguson LR (2002). "Kiwifruit promotes laxation in the elderly".Asia Pac J Clin Nutr.11(2): 164–8.doi:10.1046/j.1440-6047.2002.00287.x.PMID12074185.S2CID15280086.
- ^Stacewicz-Sapuntzakis M, Bowen PE, Hussain EA, Damayanti-Wood BI, Farnsworth NR (2001). "Chemical composition and potential health effects of prunes: a functional food?".Critical Reviews in Food Science and Nutrition.41(4): 251–86.doi:10.1080/20014091091814.PMID11401245.S2CID31159565.
- ^abcBerardi M, Tietze KJ, Shimp LA, Rollins CJ, Popovich NG (2006).Handbook of Nonprescription Drugs(15th ed.). Washington, D.C.: American Pharmaceutical Association.ISBN978-1582120744.
- ^abKrinsky, Daniel L. (November 30, 2020).Handbook of Nonprescription Drugs: An Interactive Approach to Self-Care, 20th Edition.2215 Constitution Avenue, N.W. Washington, DC 20037-2985: The American Pharmacists Association.doi:10.21019/9781582123172.ch15.ISBN978-1-58212-317-2.
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:CS1 maint: location (link) - ^Bowles-Jordan, Jane."Constipation".CPS.RetrievedMarch 20,2020.
- ^abBerardi M, Tietze KJ, Shimp LA, Rollins CJ, Popovich NG (2006).Handbook of Nonprescription Drugs(15th ed.). Washington, D.C.: American Pharmaceutical Association.ISBN978-1582120744.
- ^Laxative (Oral Route)fromMayo clinic.Last updated: Nov. 1, 2012
- ^Joo JS, Ehrenpreis ED, Gonzalez L, Kaye M, Breno S, Wexner SD, Zaitman D, Secrest K (1998). "Alterations in colonic anatomy induced by chronic stimulant laxatives: the cathartic colon revisited".J Clin Gastroenterol.26(4): 283–6.doi:10.1097/00004836-199806000-00014.PMID9649012.
- ^Joo, Jae Sik; Ehrenpreis, Eli D.; Gonzalez, Leopoldo; Kaye, Mark; Breno, Susan; Wexner, Steven D.; Zaitman, Daniel; Secrest, K. (June 1998). "Alterations in Colonic Anatomy Induced by Chronic Stimulant Laxatives: The Cathartic Colon Revisited".Journal of Clinical Gastroenterology.26(4): 283–286.doi:10.1097/00004836-199806000-00014.PMID9649012.
- ^Research, Center for Drug Evaluation and."Postmarket Drug Safety Information for Patients and Providers - Zelnorm (tegaserod maleate) Information".www.fda.gov.Retrieved14 April2018.
- ^"European Medicines Agency EPAR summary for the public"(PDF).europa.eu.Archived fromthe original(PDF)on 14 April 2018.Retrieved14 April2018.
- ^"Health Canada, Notice of Decision for Resotran".hc-sc.gc.ca.Archived fromthe originalon 18 March 2017.Retrieved14 April2018.
- ^Dharmananda, Subhuti."SAFETY ISSUES AFFECTING HERBS: How Long can Stimulant Laxatives be Used?".Institute for Traditional Medicine.Retrieved2010-03-19.
- ^"Stimulant Laxatives".Family Practice Notebook, LLC. 2010-02-26.Retrieved2010-03-19.
- ^Di Palma JA, Cleveland MV, McGowan J, Herrera JL (2007). "A randomized, multicenter comparison of polyethylene glycol laxative and tegaserod in treatment of patients with chronic constipation".Am. J. Gastroenterol.102(9): 1964–71.doi:10.1111/j.1572-0241.2007.01365.x.PMID17573794.S2CID32055676.
- ^Attar A, Lémann M, Ferguson A, Halphen M, Boutron MC, Flourié B, Alix E, Salmeron M, Guillemot F, Chaussade S, Ménard AM, Moreau J, Naudin G, Barthet M (1999)."Comparison of a low dose polyethylene glycol electrolyte solution with lactulose for treatment of chronic constipation".Gut.44(2): 226–30.doi:10.1136/gut.44.2.226.PMC1727381.PMID9895382.
- ^Dipalma JA, Cleveland MV, McGowan J, Herrera JL (2007). "A randomized, multicenter, placebo-controlled trial of polyethylene glycol laxative for chronic treatment of chronic constipation".Am. J. Gastroenterol.102(7): 1436–41.doi:10.1111/j.1572-0241.2007.01199.x.PMID17403074.S2CID10946562.
- ^Lederle FA, Busch DL, Mattox KM, West MJ, Aske DM (1990). "Cost-effective treatment of constipation in the elderly: a randomized double-blind comparison of sorbitol and lactulose".Am J Med.89(5): 597–601.doi:10.1016/0002-9343(90)90177-F.PMID2122724.
- ^"BestBETs: Is polyethylene glycol safe and effective for chro..."Retrieved2007-09-06.
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- ^Brown NW, Treasure JL, Campbell IC (2001). "Evidence for long-term pancreatic damage caused by laxative abuse in subjects recovered from anorexia nervosa".International Journal of Eating Disorders.29(2): 236–238.doi:10.1002/1098-108X(200103)29:2<236::AID-EAT1014>3.0.CO;2-G.PMID11429987.
- ^Copeland PM; Molina, H.; Ohye, Ch.; MacIas, R.; Alaminos, A.; Alvarez, L.; Teijeiro, J.; Muñoz, J.; Ortega, I. (1994). "Renal failure associated with laxative abuse".Psychother Psychosom.62(3–4): 200–2.doi:10.1159/000098619.PMID7531354.
- ^Wright LF, DuVal JW (1987). "Renal injury associated with laxative abuse".South Med J.80(10): 1304–6.doi:10.1097/00007611-198710000-00024.PMID3660046.
- ^Oster JR, Materson BJ, Rogers AI (November 1980). "Laxative abuse syndrome".Am. J. Gastroenterol.74(5): 451–8.PMID7234824.
- ^Lacey JH, Gibson E (1985). "Controlling weight by purgation and vomiting: A comparative study of bulimics".Journal of Psychiatric Research.19(2–3): 337–341.doi:10.1016/0022-3956(85)90037-8.PMID3862833.
- ^"Acid-base and electrolyte abnormalities with diarrhea".www.uptodate.com.Retrieved2017-12-12.
- ^Joo JS, Ehrenpreis ED, Gonzalez L, Kaye M, Breno S, Wexner SD, Zaitman D, Secrest K (June 1998). "Alterations in colonic anatomy induced by chronic stimulant laxatives: the cathartic colon revisited".Journal of Clinical Gastroenterology.26(4): 283–6.doi:10.1097/00004836-199806000-00014.PMID9649012.
- ^Stolberg, Michael (2003). "[The miraculous effects of taking laxatives. Success and failure of pre-modern medical treatment from the patients' perspective]".Wurzburger Medizinhistorische Mitteilungen.22:167–177.ISSN0177-5227.PMID15641192.
- ^M., Raju, S. (2013-09-30).Illustrated medical pharmacology.JP Medical.ISBN9789350906552.OCLC870530462.
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