Description is given about drugs used in geriatrics and factors that affect elderly

1. DRUG USED IN GERIATRICS
BY VRUSHALI NEVE
Asst. professor
Pharmacology dept.

2. Introduction
1.Geriatrics refers to physical, pathological aspects of elderly
2.The elderly have multiple and often chronic diseases.
3.It is not surprising tharefore that they are major consumer of
drugs.
4.Common diseases in geriatrics are:
A. Hypertension
B. Dibaties mellitus
C. Arthritis
D. Hearing loss
E. Parkinsonims disease
F. Alzheimer disease

3. PRINCIPLE UNDERLYING FACTORS
• Altered Pharmacokinetics
• Altered Pharmacodynamic
• Multiple drug therapy
• Poor compliance

4. Pharmacokinetic changes in geriatrics
Ageing result in many physiological changes that could affect
absorption, first pass metabolism ,distribution ,protein binding and
elimination of drugs
Age related changes in GI tract ,liver and kidney are:
1.Reduce gastric acid secretion
2.Decresed GI motility
3.Reduced total surface of absorption
4.Reduced splanchnic blood flow
5.Reduced liver size
6.Reduced liver blood flow
7.Reduced glomerular filtration
8.Reduced renal tubular filtration

5. 1. Absorption: There is delay in gastric emptying, reduction in
gastric acid output with aging. Absorption of some drug like
digoxin may be slower .
2. First pass metabolism: a .After absorption drug are
transported via portal circulation to liver where many lipid
soluble drugs are metabolized extensively.
b. This result in marked reduction in systemic bioavailability.
c. Minor reduction in first pass metabolism can result in
significance increase in bioavailability of such drugs.
3. Distribution: Age related physiological change which may affect
drug distribution are :
1. reduced lean body mass
2.Reduced total body water
3. Increased total body fat
4. Lower serum albumin level

6.  Increased body fat in eldrly result in increased volume of
distribution for fat soluble compound such as clomethiazole
,diazepam.
 Reduction in body water result in reduced volume of
distribution of water soluble drugs like cimetidine, digoxin,
alcohol
 Plasma albumin level decreases with age therefore free
fraction of acidic drugs like cimetidine, furosemide will
increases

7. 4. Renal clearance: There will be variability in renal function in
elderly , in general glomerular filtration rate decline which affect
renal plasma flow and renal tubular function. Because of marked
variability in renal function in elderly dosage of predominantly
renaly excreted drug should be indiviuialized.
5.Hepatic clearance, ClH: It is depend on hepatic blood flow Q,
and steady state extraction ratio E, as seen in formula :
Cl H = Q × Ca- Cv/Ca
where Ca and Cv are arterial and venous
concentrations of drug

8. Pharmacodynamics
1.Age related changes in specific receptors and target sites:
1.α adrenoreceptors: It appears to reduced with ageing while α1
adrenoreceptor responsivness is unaffected
2.β adrenoreceptors: Its function is decline with age. It is recognise
that chronotropic response to isoprenaline infusion is less marked
in elderly

9. 2.Reduction in homeostasis:
1. Orthostatic circulatory response: Structural changes in vascular
tree that occur with ageing . Antihypertensive drug with α receptor
blocking effect, antiparkinson drugs more likely to produce
hypotension in elderly
2.Thermoregulation: Increases of thermoregulatory mechanism in
elderly .Ex. Benzodiazepines, opioids, alcohol.
3. Congitive function :Aging is associated with marked structural
and neurochemical changes in CNS

10. Drugs that need to be used with caution in
elderly
DRUGS SIGNIFICANT ADR SPECIAL
CONSIDERATION
NSAID GI, Ulceration, bleeding
renal impairment
First try Paracetamol,
monitor renal function
Antibiotic- Cotrimazole Serious hypersensitivity
reaction
Trimethoprime is equally
safe, effective for UTI
Sulfonylureas (long
acting)
Increase risk of
hypoglycemia
Shorter acting agents are
preferred
Colchicine Diarrhoea ,dehydration Not recommended for
chronic therapy

11. Principle and goals of drug therapy
1. Unnecessary use of hypnotics should be avoided in mild
hypertension
2. Aim of treatment is not just to prolong life but also to improve
quality of life
3. Drug history will help to avoid potentially serious drug
interaction
4. Dose titration will help to know age related alteration that may
effect drug response
5. Packaging and labeling: Many elderly patients with arthritis
find it difficult to open container

12. Care to be taken
 Select drugs reported to be safe
 Avoid unsafe drugs
 Prepare dose and dosing schedule
 Record drug history carefully before prescription
 Try to reduce use of number of drugs

13. THANK YOU