When prescribing for the elderly, ‘start low and go slow’ is the golden rule. Starting with a third to half the recommended dosage may help eliminate potential ill effects (Geriatrics, 1996; 51: 26-30, 35). In addition, there’s a whole range of medications considered inappropriate for the elderly. Many produce ‘anticholinergic effects’: they disrupt parasympathetic nervous system function, resulting in confusion, blurred vision, constipation, dry mouth, lightheadedness, voiding difficulties and loss of bladder control. The list below was culled from the Beers list of inappropriate drugs for older patients (Arch Intern Med, 1991; 151: 1825-32) and other data (Can Med Assoc J, 1997; 156: 385-91).
* Antiarrhythmics (e.g. disopyramide): may induce heart failure, strongly anticholinergic
* Antidepressants/antipsychotics (e.g. amitriptyline, doxepin, imipramine): highly anticholinergic and sedating
* Antidiarrhoeals (e.g. diphenoxylate): drowsiness, cognitive impairment and dependence
* Antiemetics (e.g. trimethobenzamide): tremors, restlessness, changes in breathing and heart rate
* Antihistamines (often, over-the-counter drugs used to treat the common cold): strongly anticholinergic, wrongly used to induce sleep; if taken for seasonal allergies, go for the lowest effective dose
* Antihypertensives (e.g. methyldopa, reserpine): methyldopa can slow heart rate and cause depression; reserpine causes depression, erectile dysfunction, sedation and lightheadedness
* Barbiturates (all except phenobarbital): highly addictive, more side-effects than other sedative hypnotics; should not be started as a new therapy except for seizures
* Benzodiazepines (e.g. chlordiazepoxide, diazepam, flurazepam, triazolam): prolonged sedation, increased risk of falls and fractures; triazolam may cause mental and behavioural abnormalities
* Gastrointestinal antispasmodics (e.g. belladonna-containing Donnatal, clidinium, hyoscyamine, propantheline): highly anticholinergic, substantially toxic in general
* Genitourinary antispasmodics (e.g. oxybutynin): anticholinergic effects; use the lowest effective dose
* Hypoglycaemic agents (e.g. chlorpropamide): slow to clear from the body; prolonged and serious hypoglycaemia, serious oedema
* Meprobamate (e.g. Miltown, Equanil): for anxiety, highly addictive and sedating, may contribute to falls and fractures
* Methylphenidate (Ritalin): agitation, stimulation of the central nervous system, seizures
* Narcotics (e.g. meperidine, pentazocine, propoxyphene): addictive; hallucinations and confusion; ineffective for pain relief
* NSAIDs (e.g. indomethacin, phenylbutazone, ketorolac, mefenamic acid, piroxicam): indomethacin causes serious central nervous system effects; phenylbutazone suppresses bone marrow; ketorolac, mefenamic acid and piroxicam increase the risk of upper gastrointestinal bleeding
* Peripheral vasodilators (e.g. cyclandelate, ergot mesyloids): for dementia and migraine; rarely effective
* Platelet-aggregation inhibitors (e.g. dipyridamole, ticlopidine): prevent blood from clotting in stroke or heart attack victims; ticlopidine is no better than aspirin, but is more toxic
* Skeletal muscle relaxants: of questionable effectiveness; anticholinergic effects, sedation and weakness.