Laxatives adverse effects

Polyethylene glycol (PEG, MiraLax) is an osmotic laxative available only by prescription. It is useful in patients who are experiencing acute constipation and who have had inadequate response to more traditional agents. Principal adverse effects include upset stomach, bloating, cramping, and gas. 

Because many elderly persons experience constipation, laxative use is sometimes viewed as a normal part of daily life. However, mineral oil can be a special hazard in bedridden elderly persons because it can lead to pneumonia through inhalation of oil droplets into the lungs. Lactulose may be a better choice in this situation. Regular use of any laxative that affects fluid and electrolytes may result in significant unwanted adverse effects. 

Lubricant laxatives. Liquid paraffin (paraffinum subliquidum) is almost nonabsorbable and makes feces softer and more easily passed. It interferes with the absorption of fat-soluble vitamins by trapping them. The few absorbed paraffin particles may induce formation of foreign-body granulomas in enteric lymph nodes (paraffinomas). Aspiration into the bronchial tract can result in lipoid pneumonia. Because of these adverse effects, its use is not advisable. 

This is a semisynthetic disaccharide which is not absorbed from the GI tract. It produces an osmotic diarrhoea of low pH, and discourages the proliferation of ammonia-producing bacteria. It is therefore useful in the treatment of hepatic encephalopathy. Osmotic laxatives like lactulose, sorbitol, and lactilol rarely cause significant adverse effects. Glycerol suppositories are useful in softening and lubricating passage of inspissated faeces. 

Prussian blue has not been associated with significant adverse effects. Constipation, which may occur in some cases, should be treated with laxatives or increased dietary fiber. 

Supportive therapy for acute opioid poisoning may be performed first by stomach wash, and then laxative and intensive supportive therapy to treat respiratory failure and shock. Further, naloxone may be given to treat severe respiratory depression and coma. However, intravenous infusions are preferred if the toxicity is the result of a long-acting opioid. The treatment of adverse effects itself may cause withdrawal symptoms.32... 

From the description of the adverse effects, a stimulating laxative seems most likely, as they commonly cause abdominal cramps. Senna is a stimulant laxative and is available as brown tablets, and so this seems the most likely laxative. 

Yes. Although stimulant laxatives are often considered to be second line, it has been said that laxative choice is best based on symptoms, patients preference, adverse effects and cost. In the case of Mr A the stimulant laxatives have the advantage of being fairly quick acting, and are often useful to counteract the effects of decreased bowel motility caused by opioid analgesics. They are also useful for occasional use. 

Bulk laxatives are really a more long-term solution. Bisacodyl may be an alternative stimulant laxative, but is likely to have similar adverse effects. 

Q7 Comment on the adverse effects which are associated with the use of laxatives. Q8 What advice might be useful for this patient ... 

Q7 Laxatives are often misused/abused, for example in slimming disorders, to increase gut transit rate and so limit absorption of foods. Side effects which may occur include flatulence, and abdominal distension or discomfort with bulk-forming and osmotic laxatives. Other adverse effects may include diarrhoea, nausea, vomiting, weakness, dehydration and electrolyte imbalances, for example hypokalaemia. The most prominent side effect of the powerful stimulant/irritant laxatives is abdominal cramping, which is due to increased peristalsis. 

Adverse effects of laxative use or misuse include flatulence, abdominal distension, cramps and discomfort, diarrhoea, weakness, dehydration and electrolyte imbalances. 

The safety and efficacy of senna have been reviewed (4). Its rhein-anthrone-induced laxative effects occur through two distinct mechanisms, an increase in intestinal fluid transport, which causes accumulation of fluid intralumm-ally, and an increase in intestinal motihty. Senna can cause mild abdominal complaints, such as cramps or pain. Other adverse effects are discoloration of the urine and hemorrhoidal congestion. Prolonged use and overdose can result in diarrhea, extreme loss of electrolytes, especially potassium, damage to the surface epithelium, and impairment of bowel function by damage to autonomic nerves. Abuse of senna has also been associated with melanosis coli, but resolution occurs 8-11 months after withdrawal. Tolerance and genotoxicity do not seem to be problems associated with senna, especially when used periodically in therapeutic doses. 

Guar gum is a low-viscosity water-soluble dietary fiber that has been used to treat diabetes because it slows the absorption of glucose from the gut. However, adverse effects such as regurgitation, obstipation, abdominal cramps, diarrhea, and itching are common (1). Partially hydrolysed guar gum has been added to enteral formulas and food products as a source of dietary fiber it can reduce laxative use, diarrhea in septic patients receiving total enteral nutrition, and symptoms of irritable bowel sjmdrome (2). 

Xing JH, Soffer EE. Adverse effects of laxatives. Dis Colon Rectum 2001 44(8) 1201-9. 

Saline laxatives (magnesium citrate, magnesium sulfate, sodium sulfate, and disodium phosphate) or saccharide laxatives (sorbitol, mannitol, lactulose) are also used in poisoned patients. Common adverse effects are abdominal cramps, excessive diarrhea, and abdominal distension. Dehydration and electroljde imbalance in children, and hjrpermagnesemia and magnesium toxicity (with magnesium-based cathartics) have also been reported. 

All of the anthraquinones can cause cramping and abdominal discomfort. Chronic use can be associated with melanosis coU. The urine can be colored red. The possibihty of colonic injury has been discussed (see General adverse effects of laxatives in this monograph). Hepatitis, confirmed by rechallenge, has been reported, possibly due to re-absorption of rhein anthron produced in the intestine (SEDA-16, 425). 

Bisacodyl increases peristalsis by a direct effect on the small intestine. Its only specific adverse effect is abdominal cramping, which a minority of patients find troublesome. As with other laxatives, however, heavy or chronic use can derange the system in various ways, for example hypokalemia with rhabdomyolysis (SEDA-16, 425). 

Phenolphthalein was once widely used as a laxative for self-treatment, often camouflaged in chocolate and thus hable to abuse or accidental use it is now obsolete. Skin rashes of various types are repeatedly reported, sometimes with pruritus. Pigmentation defects have been described. The most serious albeit rare adverse effect on the skin to have been rehably documented is toxic epidermal necrolysis. A fixed drug eruption with bullous eiythema multiforme is associated with auto-sensitiza-tion, and direct intracellular immunofluorescence is found (19). A hjrpothesis that phenolphthalein might increase the risk of development of adenomatous colorectal polyps has not been confirmed (20). 

The osmotic laxatives include inorganic salts and the synthetic disaccharide, lactulose, as well as magnesium salts and sodium phosphate. Osmotic agents are largely free of adverse effects, apart from flatulence, cramps, and abdominal discomfort. 

The most common adverse effects of lactulose are flatulence, cramps, and abdominal discomfort. Non-toxic megacolon has been seen in some elderly patients and, as with other laxatives, there is always a possibility of dependence (SEDA-11, 374). 

Liquid paraffin is a mixture of liquid hydrocarbons. Its main use has been as a lubricant laxative but it is not recommended, because of its adverse effects. Nevertheless, it continues to be used for this purpose and is reportedly as effective as lactulose (1). However, the erstwhile Committee on Safety of Medicines in the UK recommended the following precautions (2) ... 

Docusate salts are used in oral formulations as therapeutic agents for their fecal softening and laxative properties. As a laxative in adults, up to 500 mg of docusate sodium is administered daily in divided doses in children over 6 months old, up to 75 mg in divided doses is used. The quantity of docusate sodium used as an excipient in oral formulations should therefore be controlled to avoid unintended laxative effects.Adverse effects associated with docusate sodium include diarrhea, nausea, vomiting, abdominal cramps, and skin rashes. As with the chronic use of laxatives, the excessive use of docusate sodium may produce hypomagnesemia. ... 

Esophageal obstruction may occur if methylcellulose is swallowed with an insufficient quantity of liquid. Consumption of large quantities of methylcellulose may additionally interfere with the normal absorption of some minerals. However, this and the other adverse effects discussed above relate mainly to the use of methylcellulose as a bulk laxative and are not significant factors when methylcellulose is used as an excipient in oral preparations. 

Excessive administration of phosphate, particularly intravenously, rectally, or in patients with renal failure, can cause hyperphosphatemia that may lead to hypocalcemia or other severe electrolyte imbalances. Adverse effects occur less frequently following oral consumption, although phosphates act as mild saline laxatives when administered orally or rectally. Consequently, gastrointestinal disturbances including diarrhea, nausea, and vomiting may occur following the use of dibasic sodium phosphate as an excipient in oral formulations. However, the level of dibasic sodium phosphate used as an excipient in a pharmaceutical formulation is not usually associated with adverse effects. 

The main adverse effects of stimulant laxatives are griping and intestinal cramps... 

Bulk-forming laxatives have few adverse effects. The only major caution in the use of bulk-forming laxatives is that obstruction of the esophagus, stomach, small intestine, and colon has been reported when the agents have been consumed without sufficient fluid or in patients with intestinal stenosis. 

Mood Stabilizers (Lithium and Anticonvulsants). Due to the lack of evidence demonstrating their benefit, lithium and anticonvulsants are reserved for BN patients with a comorbid bipolar affective disorder. Target serum concentrations and doses are similar to those used for patients with seizure or mood disorders. Lithium must be used cautiously, because purging and laxative abuse increases the risk of toxicity. The adverse effect of weight gain often makes mood stabilizers and anticonvulsants unacceptable to patients in the long term. 

One study showed aloe to be an effective treatment in patients with chronic constipation in combination with psyllium and celandine, a stimulant laxative obtained from the Chelidonium majus plant (Odes and Madar, 1991). An earlier study showed aloin to be effective alone, and even more effective in combination with phenolphthalein (Chapman and Pittelli, 1974). Gas and cramps were the major adverse effects with treatment. 

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