The Problems of Anticholinergic Adverse Effects in Older Patients

Abstract

The old saying 'red as a beet, dry as a bone, blind as a bat, hot as a hare, mad as a hatter' is often quoted when describing the autonomic effects of drugs that block the muscarinic cholinergic system. These effects may be subtle or dramatic, yet can be overlooked or discounted as a natural consequence of old age. Elderly patients can be particularly sensitive to the anticholinergic action of drugs because of physiological and pathophysiological changes that often accompany the aging process. The use of multiple drugs, a common finding in older patients, may result in pharmacodynamic and pharmacokinetic drug interactions that heighten anticholinergic effects. While the classic anticholinergic problems of decreased secretions, slowed gastrointestinal motility, blurred vision, increased heart rate, heat intolerance, sedation and possibly mild confusion, may be uncomfortable for a younger patient in relatively good health, these effects can be disastrous for older patients. Even the most common peripheral anticholinergic complaint of dry mouth can reduce the ability to communicate, predispose to malnutrition, promote mucosal damage, denture misfit or dental caries, and increase the risk of serious respiratory infection secondary to loss of antimicrobial activity of saliva. Mydriasis and the inability to accommodate will impair near vision and may precipitate narrow angle glaucoma in predisposed patients, but less obviously could lead to an increased risk of accidents, including falls. Somatic complaints of constipation and urinary hesitancy, could, in the presence of anticholinergic challenge, result in faecal impaction or urinary retention. Cardiac effects may be poorly tolerated. Increases in heart rate may precipitate or worsen angina. Finally, thermoregulatory impairment induced by anticholinergics, which block the ability to sweat, may lead to life threatening hyperthermia. Central anticholinergic effects range from sedation, mild confusion and inability to concentration to frank delirium. Even mild effects can reduce function and increase dependency. At any level of care, the loss of independence increases the caregiver burden, costs, and most importantly, can negatively affect quality of life. Many age-related and disease-related conditions may predispose elderly patients to anticholinergic drug toxicity. Careful attention to anticholinergic effects when prescribing drugs, patient education, regular review of the entire drug regimen, and familiarity with the signs and symptoms of anticholinergic toxicity will help to reduce the risk of drug-induced problems.

A randomised controlled trial comparing sugammadex and neostigmine at different depths of neuromuscular blockade in patients undergoing laparoscopic surgery*

“…However, the neostigmine group reported a greater number of adverse events considered by the blinded safety assessor to be related to the study drug, most commonly bradycardia, which is well recognised as a potential side effect of neostigmine [11,12]. To combat such side effects, anticholinergic drugs such as atropine and glycopyrronium are frequently co-administered, although these drugs may in turn lead to adverse events of their own, including tachycardia, decreased secretions and blurred vision [13]. Thus, there is reluctance, particularly in central Europe, to administer acetylcholinesterase inhibitors for the reversal of neuromuscular blockade [14], with one survey suggesting that only 18% of European anaesthetists routinely use pharmacological reversal of neuromuscular blockade [15].…”

Health problems associated with lower urinary tract symptoms in older women

“…In particular, drugs with anticholinergic properties may negatively affect the contractility of the urinary bladder, leading to voiding difficulties and risk of urinary retention [17]. According to recent data, use of such psychotropic medications and sedatives is especially common in the older population [18].…”

Comparison of effects of sugammadex and neostigmine on QTc prolongation in rabbits under general anesthesia

“…Used alone neostigmine may bring out side effects such as bradycardia and increased salivation. As a result to antagonize the side effects of neostigmine during removal of nondepolarizing block it is necessary to use muscarinic antagonists such as atropine 15 . However as the use of atropine stimulates the anti-muscarinic receptors, cardiovascular, gastrointestinal and respiratory side effects may be observed.…”