Prescribing for the Elderly Flashcards
Changes in absorption in older adults
higher gastric pH (production of acid drops)
increased GI transit time
**overall, despite these changes, there is very little change in absorption of drugs overall
These are two drugs that should not be taken together
calcium
levothyroxine
Chronic illness is associated with lower levels of serum (blank).
albumin
**Highly protein bound drugs may be affected by acute displacement
(blank) is elevated in acute illness and may affect binding of basic drugs
Acid 1 α-glycoprotein
What happens to body water as you age? Body fat?
Why does this matter?!
body water decreases
fat content increases;
some drugs are water soluble vs fat soluble & there metabolism will be affected!
Which phase of metabolism is most affected by aging?
phase 1: oxidation, reduction, hydrolysis are most affected by aging
phase 2: Acetylation, glucuronidation, sulfation, glycine conjugation are mostly unaffected by aging
What happens to P450 metabolizing enzymes as you age?
they decrease!
What happens to the 1/2 lives of some drugs in the elderly?
they increase!
ex: benzos have a much higher 1/2 life in the elderly!
What happens to elimination of drugs with increasing age?
it decreases because renal function decreases
Which drugs are predominately eliminated via the renal route?
Digoxin Aminoglycoside antibiotics Lithium Spironolactone Vancomycin
What can be used to estimate clearance of drugs?
Cockcroft-Galt equation - uses creatinine clearance
Elderly patients may have increased receptor sensitivity to these agents
opioids
some benzos
Elderly patients may have reduced response to theses agents
B-agonists - isoproterenol
What happens to incidence of preventable adverse drug reactions with increasing age?
it increases
What are some drug interactions that affect metabolism?
warfarin + antibiotics
**Drugs that inhibit warfarin’s metabolism: ciprofloxacin, clarithromycin, erythromycin, metronidazole and trimethoprim-sulfamethoxazole.
