Potentially inappropriate medications in older adults (Beers criteria)

What it is

The Beers Criteria are a list of medications that are potentially inappropriate for use in older adults, and three of its entries are named in these pages: first the sulfonylurea glyburide, second the cholinesterase inhibitor donepezil, and third the group of amitriptyline, imipramine and paroxetine. The 2015 update comes from an American Geriatrics Society expert panel and applies to adults 65 years of age and older. An entry names the drug, the patients in whom it should be avoided, and the reason, and it carries a rating of the evidence and of the strength of the recommendation. The entry on donepezil in a patient with syncope, for example, carries a moderate evidence level and a strong strength of recommendation.

What can go wrong

The list names particular drugs and the particular harm each of them can do. Glyburide, a sulfonylurea, is on it because of its potential to cause prolonged hypoglycemia, and it carries a risk of significant hypoglycemia especially in elderly patients. Major hypoglycemic events have been associated with a greater risk of dementia, although whether minor events also contribute to it is unknown. Donepezil, a cholinesterase inhibitor, should be avoided in patients with syncope because of an increased risk of bradycardia. The cholinergic effect of these drugs is vagotonic on the sinoatrial and atrioventricular nodes, so they can cause bradycardia or heart block in patients with or without underlying cardiac conduction abnormalities, and syncope has been reported with them. Amitriptyline, imipramine and paroxetine are highly anticholinergic and sedating and can cause orthostatic hypotension, and they carry an avoid recommendation.

A medication list in an older patient can also point at a drug harm of a different kind. Patients treated with valproic acid (VPA) have a higher incidence of hyperammonemia, and although the incidence of VPA-induced hyperammonemia varies, it should be considered in patients taking VPA who present with altered mental status or encephalopathy. In addition to discontinuing VPA, the encephalopathy should be managed with ammonia-lowering drugs such as lactulose; ammonia levels can also be elevated in patients taking VPA who do not have encephalopathy, so close monitoring of these patients for the development of encephalopathy is recommended. The alternatives are worth holding beside it: Gilbert syndrome causes an asymptomatic elevation of bilirubin in the absence of underlying hepatic disease, occult gastrointestinal bleeding should be suspected in patients with an elevated BUN level in the absence of underlying renal disease or volume depletion, and portal vein thrombosis presents with abdominal pain and other symptoms of an underlying predisposing disease such as cirrhosis.