POLYPHARMACY

ANSWER TO CASE PRESENTATION QUESTION

Q: What are some of the potential problems with this medical regimen?

A: Potential problems include:

• Drug-disease interactions
  • Anticholinergic medications such as diphenhydramine and amitriptyline, together with a diuretic, may worsen symptoms of benign prostatic hyperplasia
  • Methyldopa and/or digoxin could result in exacerbation of depression
• Drug-drug interactions
  • Tricyclic antidepressants together with antihypertensive agents could increase the risk of orthostatic hypotension and may contribute to his complaint of dizziness
• He is taking multiple drugs that could contribute to confusion.
  • Methyldopa
  • Diazepam
  • Digoxin (also could contribute to depression and anorexia)
  • Anticholinergic medications( also may contribute to prostatism and dizziness)
  • amitriptyline(the most highly anticholinergic of the tricyclic antidepressants; it is usually avoided in older people for this reason)
  • Diphenhydramine
  • Dimetapp
  • Digoxin dose may be too high for a 78 year old man with renal insufficiency (check a level)
  • A drug (meclizine) was used to treat a probable adverse effect of another drug(s) (dizziness due to amitriptyline or diuretic); a better approach is to try to reduce or discontinue the offending medication
• This patient should be encouraged to consolidate his care with a single primary care provider. Multiple physicians may not be aware of each other, and may prescribe medications that interact with one another.
• He is taking 2 beta-agonists; oral terbutaline in particular could contribute to insomnia.
• He is taking too high a dose of the hydrochlorothiazide (little additional antihypertensive benefit is achieved with >25mg daily, and the risk of hypokalemia and digoxin toxicity may be increased)

Copyright 1999, 2000 David A. Gruenewald, M.D. and Kayla I. Brodkin, M.D. All rights reserved.