Elderly, drug action

J. Roberts and N. Turner, Pharmacodynamic basis for altered drug action in the elderly, Clin. Geriatr. Med., 4, 127 (1988). 

Age can influence drug effects if the user is very young or old. Children are more sensitive to drugs because enzyme systems that metabolize drugs may not be fully developed. As a result, the drug stays active longer. In the elderly these same enzyme systems may be impaired, with the same result of increased duration of drug action. 

Medications for symptomatic relief from vertigo consist of antiemetics, benzodiazepines and antihistamines. They are all mostly aimed at the psychological consequences of dizziness and can all have highly unfavourable side effects, for example, sedation, anticholinergic effects and insomnia. The psychological consequences of dizziness in elderly should rather be treated with information about the condition, supportive help actions and increased social activities, than with drugs. 

Because of the anticholinergic action of these agents, use with caution and with appropriate monitoring in patients with glaucoma, obstructive disease of the Gl or GU tract, and in elderly males with possible prostatic hypertrophy. These drugs may have a hypotensive action, which may be confusing or dangerous in postoperative patients. 

Citalopram (Celexa) [Antidepressant/SSRI] WARNING Closely monitor for worsening depression or emergence of suicidality, particularly in pts <24 y Uses Depression Action SSRI Dose Initial 20 mg/d, may t to 40 mg/d X in elderly hqjatic/renal insuff Caution [C, +/-] Hx of mania, Szs pts at risk for suicide Contra MAOI or w/in 14 d of MAOI use Disp Tabs, cap, soln SE Somnolence, insomnia, anxiety, xerostomia, diaphoresis, sexual dysfxn Notes May cause X Na /SIADH Interactions t Effects W/ azole antifungals, cimetidine, Li, macrolides, EtOH t effects OF BBs, carbamazepine, CNS drugs, warfarin X effects W/ carbamaz ine X effects OF phenytoin may cause fatal Rxn W/ MAOIs EMS Use caution w/ CNS depressants, may need a reduced dose concurrent EtOH... 

Because of its anticholinergic properties, disopyramide should not be used in patients with glaucoma. Urinary retention and benign prostatic hypertrophy are also relative contraindications to disopyramide therapy. Patients with myasthenia gravis may have a myasthenic crisis after disopyramide administration as a result of the drug s local anesthetic action at the neuromuscular junction. The elderly patient may exhibit increased sensitivity to the anticholinergic actions of disopyramide. 

---