Geriatrics Flashcards
Main challenges in elderly
multiple co-morbidities, polypharmacy, compliance, cost, new drugs
Leading causes of mortality
CVD, CA, respiratory
Leading causes of morbidity
arthritis, HTN, hearing loss, heart disease
Gastrointestinal changes w/ elderly
inc stomach pH, dec blood flow, slowed gastric emptying
Skin changes w/ aging
thinning of dermis, loss of SQ fat
Body composition changes w/ againg
decreased total body water, decreased lean body mass, body fat percentage changes
Liver changes w/ aging
dec liver mass, dec blood flow, dec or no change to CYP 450
Renal changes w/ aging
dec glomerular filtration rate, dec blood flow, dec tubular secretion, dec mass, dec functional nephrons
Absorption problems
rate of absorption decreased, little change in extent of absorption
Decreased body water causes
higher drug concentrations and affects hydrophilic drugs
Decreased lean body mass effects
lipid soluble drugs increased half-life
Decreased plasma protein effects
highly protein bound drugs increased free fractions
Effects of metabolism changes
reduction in first-pass metabolism, phase II metabolism is less affected by age
limitations in measuring CrCl
not everyone has decline in renal function, muscle mass reductions
Pharmacodynamic changes
reduced sensitivity to B-adrenergic stimulation, impaired baroreceptor reflex, more sensitive to antagonism of cholinergic receptors, CNS disorders, increased effects on some meds
CNS changes w/ aging
volume loss, slower processing, more activation required more simple tasks, dopaminergic decrease, serotonergic changes with depression, memory and cognition changes, sympathetic outflow increased
Drugs that affect bone and muscle integrity
glucocorticosteroids, PPIs, phenytoin
Drugs that affect balance
sedative hypnotics, antiHTN, long T1/2 or large dose benzos, TCAs, antipsychotics, anticonvulsants
Drugs that affect mental state
anticholinergics, benzos, pentazocine, muscle relaxants, TCAs, amitryptyline, antispasmodics, diphenhydramine, antihistamines
Drugs that affect emotional state
methyldopa, reserpine, anastrozole, interferon a-2b, tamoxifen
Drugs that affect continence
anticholinergics, a-blockers, a-agonists, alcohol, acetylcholinesterase inhibitors, diuretics
Prescribing in the elderly
start w/ low dose, avoid starting multiple agents at same time, reach therapeutic dose before switching agents, consider non-pharm approaches
Enhancing medication adherence
limit prescribing newer, expensive drugs, simplify regimen, pill organizers, educate pt on benefits, assess appropriateness of meds
Causes of constipation
dietary, failure to heed reflex, impaired physical mobility, disease, age, drugs
Drugs that cause constipation
analgesics, antacids, anticholinergics, antidepressants, verapamil, clonidine, iron
Non-pharm treatment
fluid, fiber, fitness
Bulk laxatives
psyllium (Metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon) -1250 mg PO 1-4/day
MOA of bulk laxatives
increase bulk volume and water content of stool, stimulating peristalsis and decrease colonic transit time; 12-72 hr onset
Pearls of bulk laxatives
must have adequate fluid intake, not good for bed ridden pts or opioid induced, great for chronic management, as good as stool softener
Surfactant/emollient
Docusate (Colace)- 100 mg PO BID
MOA of surfacant/emollient
decrease fecal surface tension, stool softener
Pearl of surfacant/emollient
onset- 24-72 hr, mostly PO, sometimes enema, combo (senna- Peri- colace), very safe, OTC
Saline laxatives (Cathartics)
magnesium citrate (300 ml), Magnesium hydroxide (MOM, 30 ml), sodium bi/phosphate (Fleets phospho-soda), fleets enema
MOA of saline laxatives
draws fluid into colon and stimulates activity
pearls of saline laxatives
onset- 30min-3 hr, great for acute, avoid in pt w/renal disease, citrate and fleets used for prep (green bullet)
Hyperosmotics
glycerin- infants, lactulose (Chronulac)- chronic, liver failure, polyethylene glycol (Miralax), polyethylene glycol-electrolyte solution (GoLytely)
Stimulants
bisacodyl (Ducolax)- 5-15 mg po, Senna (senokot), castor oil
MOA of stimulants
irritates nerves in colon, stimulates motility
Bisacodyl mostly used
for short term, once daily if chronic, OTC, also prep
Senna used for
opioid induced constipation, OTC
Lubricants
mineral oil, lubricates intenstine, decreases water absorption, onset 6-8 hrs, not used often
Laxative ADRs
abd cramping, bloating, flatulence, distension, diarrhea, saline lxatives can cause diuresis, dehydration, electrolyte imbalances, bulk lax can cause GI obstruction
General treatment guideline for constipation
first bulk-forming, surfactant/emollient or lubricant, saline cathartic, hyperosmotic agent, then stimulant
Special populations
elderly-docusate, lactulose, fiber, pregnancy-fiber, children- glycerin suppositories, polyethylene glycol, diabetics- metoclopramide, stimulant, post op- MOM, maybe stimulant
Restless leg syndrome non-pharm
avoid EtOH, tobacco, Fe, avoid drugs that alter serotonin, follow regular sleep patterns, exercise, avoid prolonged sedentary activities, stretch, massage leg
RLS pharm approach
dopaminergic agents, give before bed, levodopa/carbidopa- may be best option, dopamine agonists (Pramipexole (Mirapex), Ropinirole (requip)), sedatives, hypnotics, anticonvulsants, opioids
