Laxatives: Delirium Trigger?

Laxatives are not typically considered dangerous, but they may cause serum electrolyte imbalance and rhabdomyolysis. Delirium is a syndrome defined by the American Psychiatric Association as a disturbance of consciousness and a change in cognition that develops over a short period of time. It is associated with anticholinergic activity and is often seen in clinical practice. Delirium is a common occurrence on geriatric in-patient wards and can result in other complications such as bowel obstruction. Constipation is a frequent, often overlooked precipitating factor for delirium. It is associated with immobility, comorbid diseases, and even depression.

An 87-year-old woman was hospitalised for confusion, tremors, an inability to walk, and a fever. She was a frequent user of high dosages of lactulose and sorbitol syrup as a laxative. During her hospitalisation, the patient presented acute delirium, which was treated with haloperidol and prometazine chloridrate.

Laxatives and delirium in elderly patients

Laxatives are associated with delirium in elderly patients. Laxatives are a common cause of delirium in older adults, with an overall incidence of 22% to 39%. Delirium is a medical emergency with significant associated morbidity and mortality requiring rapid diagnosis and management. It is a syndrome defined by the American Psychiatric Association as "a disturbance of consciousness and a change in cognition that develops over a short period of time". The elderly are at an increased risk of developing delirium due to a variety of factors, including advanced age, pre-existing cognitive impairment, functional impairment, and male gender.

Laxatives, particularly those with anticholinergic properties, can cause or worsen delirium. Anticholinergic drugs are known to cause delirium by increasing serum anticholinergic activity. This can lead to a disturbance in consciousness and cognition, which are characteristic features of delirium.

In elderly patients, the use of laxatives can lead to an increased risk of delirium due to several factors. Elderly individuals often have a reduced kidney function, which can affect the excretion of drugs, including laxatives. This can lead to a buildup of the drug in the body, increasing the risk of side effects, including delirium. Additionally, elderly patients may have a higher sensitivity to the effects of laxatives due to age-related changes in the body's response to medications.

Furthermore, the use of laxatives in elderly patients may be an indicator of other underlying conditions that can contribute to delirium. For example, constipation, which is common in older adults, can be a side effect of certain medications or a result of immobility. These factors can increase the risk of delirium.

The management of delirium in elderly patients requires a comprehensive approach. It is important to address the underlying causes, such as discontinuing or reducing the dose of laxatives, improving hydration, and treating any underlying conditions that may be contributing to delirium. Non-pharmacological interventions, such as reorientation and environmental modifications, are often the first-line treatment for delirium. Pharmacological interventions, such as antipsychotic medications, may be considered if non-pharmacological approaches are ineffective or if the patient is at risk of harming themselves or others.

In summary, laxatives are associated with delirium in elderly patients, and the management of delirium requires a multidisciplinary approach that addresses the underlying causes and utilizes both non-pharmacological and pharmacological interventions.

Laxatives and electrolyte imbalances

Laxatives are often not considered dangerous, but they can cause serum electrolyte imbalances, especially in the elderly. Electrolyte imbalances can lead to muscle weakness and are associated with delirium.

The body's electrolyte balance is maintained by the nervous system, endocrine signalling, the gastrointestinal microbiota, ion channels, and aquaporins. Electrolyte imbalances can be caused by a variety of factors, including diet, pace of life, and complex social and psychological factors.

The most common electrolytes that are affected by laxatives are sodium, potassium, chloride, and calcium. These electrolytes are essential for maintaining the body's fluid balance, nerve and muscle function, and acid-base balance.

Laxatives can cause electrolyte imbalances by increasing the loss of electrolytes through the intestines. This can happen when laxatives draw water into the intestines, which can flush out electrolytes. Some laxatives can also interfere with the absorption of electrolytes in the intestines.

The risk of electrolyte imbalances from laxatives is higher in people who are dehydrated, have kidney or liver disease, or are taking certain medications. It is important to monitor electrolyte levels in people who use laxatives, especially in the elderly, to prevent serious health complications.

Laxatives and anticholinergic activity

Anticholinergics are a type of medication that blocks the action of acetylcholine, a neurotransmitter that transfers signals between cells to affect specific bodily functions. Anticholinergics can treat a variety of conditions, including chronic obstructive pulmonary disease (COPD), overactive bladder, incontinence, gastrointestinal disorders, and symptoms of Parkinson's disease. Anticholinergics are also used as muscle relaxants during surgery to block neuromuscular reactions and stop saliva production.

Laxatives are medications used to treat constipation, which is when there are too few stools or stools that require effort to pass. There are five categories of laxatives: fiber supplements, stool softeners, osmotic agents, lubricants, and stimulants. Laxatives work by facilitating the movement of water and fats into the stool, softening the stool, and improving the regularity of bowel movements.

Some laxatives, such as docusate, are stool softeners that facilitate the movement of water and fats into the stool. Others, like milk of magnesia and polyethylene glycol, are osmotic agents that cause water to be retained with the stool, increasing the number of bowel movements and softening the stool. Mineral oil enemas are an example of lubricant laxatives that coat the stool to help seal in water. Bisacodyl is a stimulant laxative that causes the intestines to contract, inducing stool movement through the colon.

While anticholinergics and laxatives serve different purposes, there is some overlap in their mechanisms of action. Anticholinergics include both prescription and over-the-counter drugs that block acetylcholine from binding to its receptors on nerve cells, inhibiting involuntary muscle movements. Laxatives, particularly those with osmotic activity, can also affect acetylcholine activity by increasing the amount of water in the intestines, thereby stimulating muscle contractions and promoting bowel movements. This indirect effect on acetylcholine may be one way that laxatives are associated with delirium, particularly in older adults who are more susceptible to adverse drug effects.

Anticholinergic drugs have been identified as a common cause of delirium in older adults, especially those with pre-existing cognitive impairment or dementia. Anticholinergics can cause side effects such as confusion, memory loss, and worsening mental function in people over 65. As a result, the American Geriatrics Society recommends avoiding the use of anticholinergic medications in this population. The long-term use of anticholinergics has been linked to an increased risk of dementia, and anticholinergic toxicity can lead to severe side effects, including hallucinations, slurred speech, and flushing.

In summary, while laxatives are not anticholinergic drugs, they can indirectly affect acetylcholine activity in the body. This, combined with the fact that older adults are more vulnerable to the adverse effects of anticholinergics, may explain the association between laxative use and delirium, particularly in the elderly. The high prevalence of laxative use in this population underscores the importance of careful medication management and monitoring to prevent adverse outcomes.

Laxatives and constipation in geriatric patients

Constipation is a common problem in geriatric patients, with a prevalence of 24-30% in those over 65. It is more common in women, and can cause a serious decline in quality of life. Constipation is not a normal part of ageing, but it is more common due to decreased mobility, polypharmacy, and comorbidities.

Laxatives are a common treatment for constipation, but they are not without risk. Over-the-counter laxatives are often not considered dangerous, but they can cause electrolyte imbalances and rhabdomyolysis. Electrolyte imbalances are more common in the elderly, and can be caused by a number of factors, including polypharmacy, malnutrition, and comorbidities.

A careful review of all medications is one of the most important duties of a physician treating elderly patients, as drug interactions and side effects can be fatal. Laxatives have a high osmotic power, which can lead to the movement of large amounts of liquid and salts in the intestine.

Laxatives can be used to treat constipation in geriatric patients, but it is important to first address any reversible causes of constipation, such as dehydration, uncontrolled pain, urinary retention, and constipation. It is also important to ensure adequate pain control, as this can be a cause of constipation.

Laxatives should be used with caution, and non-pharmacological treatments should be considered first. Bulk-forming agents, such as psyllium, are effective in managing constipation, but they must be taken with enough water to prevent impaction. Osmotic laxatives, such as lactulose and polyethylene glycol, are also effective and are generally safe for long-term use. Stimulant laxatives, such as bisacodyl, are a last resort and should only be used 3 times a week or less, as they can cause abdominal pain and bloating.

Laxatives and delirium: treatment and prevention

Delirium is a serious medical condition characterised by disturbances in consciousness and cognition, with an acute onset and fluctuating course. It is a common occurrence in elderly patients, often as a result of taking multiple medications, and is associated with increased mortality. Delirium can be caused by a number of factors, including constipation, which is prevalent in older adults. Constipation is often treated with laxatives, but these can sometimes lead to iatrogenic diarrhoea, which can, in turn, cause dehydration and delirium. Therefore, the appropriate use of laxatives is important for the prevention and treatment of delirium.

Treatment and Prevention

The appropriate management of laxatives can help prevent and treat delirium. Educational sessions for healthcare professionals can ensure the correct prescription of laxatives, including guidance on when to prescribe laxatives and how to titrate dosage. Non-pharmacological alternatives to laxatives, such as optimising hydration, exercise, and a high-fibre diet, should also be considered.

In the treatment of delirium, it is important to first address any underlying causes, such as pain, urinary retention, constipation, dehydration, environmental factors, and polypharmacy. Ensuring adequate pain control is essential, and opioids may be necessary despite the risk of delirium. Urinary retention can be addressed through bladder decompression via straight catheterisation, and constipation can be treated with stool softeners and disimpaction. Dehydration can be treated with intravenous fluids, and environmental factors, such as noise and temperature, can be modified to reduce sensory overload. Finally, a review of the patient's medication can identify any drugs that may be causing or worsening delirium, particularly those with anticholinergic properties.

In cases of severe agitation, pharmacological intervention may be necessary to ensure the safety of the patient and medical staff. While benzodiazepines are commonly used to treat delirium, they are not recommended for older adults, as they can precipitate or worsen delirium and cause severe side effects. Instead, antipsychotic medications, such as haloperidol, olanzapine, quetiapine, and risperidone, are recommended. However, these medications also have side effects and limited evidence supporting their efficacy and safety in older adults, so they should be used with caution.

The appropriate management of laxatives, including both pharmacological and non-pharmacological approaches, can help prevent and treat delirium in older adults. It is important to address any underlying causes of delirium and carefully consider the benefits and risks of pharmacological interventions.

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