This document discusses drug therapy in geriatrics. It begins by listing common drug classes used to treat various conditions in elderly patients, including antibiotics, antiallergics, antiasthmatics, and antihypertensives. It then discusses several age-related changes to pharmacokinetic and pharmacodynamic processes in geriatric patients. These changes can impact drug absorption, distribution, metabolism, and excretion. It also notes an increased risk of drug interactions and adverse reactions in elderly patients due to polypharmacy and physiological changes. Finally, it discusses the role of pharmacists in optimizing drug therapy for geriatric patients.

1. DRUG THERAPY
IN
GERIATRICS

2. DRUG THERAPY IN GERIATRICS
1.Antibiotics agents:
Benzathine Cefixime,
Metronidazole, Fluconazole
2.Antiallergia agents:
antihistamines, Steroids
Decongestants
3.Antiasthma agents:
corticosteroids, xolair
theophylline, Leukotriene

3. 4.Antihypertensive agents:
thiazide diuretics, ACE inhibitors
calcium channel blockers,
beta blockers
angiotensin 2 receptor antagonists
5.Diuretics agents:
Loop diuretics
furosemide, torsemide
Thiazed diuretics
epitizide, bendroflumethiazide
Potassium sparing diuretics
amiloride, triamterene
spironolactones

4. DRUG THERAPY IN GERIATRICS
Definition:
Geriatrics refers to the study of physical – pathophysiological and
psychological aspects of the elderly. Geriatrics normally includes
individuals of 65 years and above.
The statistics have already reported that, the geriatric
population has been increasing constantly worldwide. The
phenomenal progress in the medical sector is a most prominent
cause. Some diseases and disorders like hypertension,
hypercholestremia, diabetes mellitus, osteoarthritis, impaired vision,
hearing loss, etc.
Drug interactions and disease drug interactions are more
prevalent in the elderly due to multiple medicines being taken,
patient related factors and the manner in which the doctor prescribes
them.

5.  Many elderly patients may not able to adhere to the dosing
schedules and the dosing instructions designed for them due to
forgetfulness confusion, hearing, vision problems.
This may lead either to overdosing of medicines that produces
unwanted effects or reduced serum concentration due to missing of
dose/does.
 Before formulating drug therapy for the elderly, it is
important for the physician to examine the medical history of the
patient, the various disease that the patient has suffered throughout
his/her lifetime, the medicines taken, any particular ingredients or
drugs that he/she is allergic to and his/her lifestyle (smoking,
drinking habits) etc.

6. Table 1 : Overall changes in body composition in the geriatric population
Sr.
No.
Change
1
2
3
4
5
6
Reduced plasma albumin content.
Reduced lean body mass.
Reduced liver and renal mass.
Reduced blood flow to major metabolizing
organ.
Reduced total body water and body size.
Increase in total adipose tissue content.

7. Ageing results in many physiological changes that could theoretically
affect absorption. First pass metabolism, protein binding, elimination of drugs, age
related changes in gastro intestinal tract, liver & kidney.
Changes includes :
→ Gastric acid secretion.
→ Gastro intestinal motility.
→ Total surface area of absorption.
→ Liver size
→ Liver Blood flow
→ Glomerular filtration
→ Renal tubular filtration

8. PHARMACOKINETIC PARAMETERS
A) Absorption:
B) Distribution:
C) Metabolism:
D) Elimination:
Creatinine clearance = (140 – Age) x weight in kgs / 72 x serum creatinine
This equation applicable to patients from age 42 to 80. This equation is given by
cock croft gault formula.

9. PHARMACODYNAMIC CONSIDERATIONS
There are several pharmacodynamic changes observed with
increasing age. These changes are mainly due to altered receptor
sensitivity, affinity towards drug and number of receptors. It is
observed that certain drugs like benzodiazepines shows enhanced
activity (increased sedation) while some drugs like β-blockers shows
diminished response (poor control of blood pressure), may be due to
up-regulation and down regulation of receptors respectively.
In general, pharmacodynamic interactions refer to the increased or
decreased drug response in the body when drugs are administered
alone or in combination with other drugs. These responses occur due
to additive, synergistic or antagonistic effects between the drugs. For
example:
1. Co-administration of benzodiazepines and chloropromazine cause
increased sedation.

10. 2. Aspirin and coumarin anticoagulants may lead to bleeding.
3. Administration of NSAID’s like aspirin with digoxin can produce
gastro-intestinal bleeding.
ADVERSE REACTIONS IN THE ELDERLY
The frequency and manifestations of adverse drug reactions in
the geriatric population is widely different from that of adults due
to the age associated changes in Pharmacodynamic pattern.
The common ADR are described in Table 3.

11. Drug Interacting
Drug
Interaction
NSAID’s Digoxin Precipitation of toxicity especially
cardiotoxicity of digoxin.
Anti-anxiety drugs
(Anxiolytics)
Alcohol Enhanced sedation due to anxiolytics.
Antidepressant Rifampicin,
Carbamazepine
Rifampicin and Carbamazepine being
enzyme inducers, hasten the metabolism of
the antidepressants thereby may cause its
therapeutic failure.
Anticonvulsants Ketoconazole,
Erythromycin
Exaggerated effect of anticonvulsants due to
inhibition of cytochrome P-450 enzyme
responsible for metabolising anticonvulsants.
Antibiotics NSAID’s Vomitting, dizziness, stomach upset.
Potassium sparing
diuretics
Potassium
supplements
Hyperkalemia
Table:2 Common adverse drug reactions

12. ROLE OF PHARMACIST IN GERIATRIC CARE
1. Pharmacists are committed to optimizing pharmaceutical therapies for
each patient to improve outcomes and reduce costs.
2. They are making significant contributions to the profession through
specialized pharmaceutical care.
3. Pharmacists, aided by a comprehensive system employing information
technology and clinical “best practices ” work with physicians to identify
patients at risk for a given disease state and ensure that optimal drug
therapy is received and unnecessary healthcare expenditures are
eliminated.
4. Medications are probably the single most important healthcare technology
in preventing illness, disability and health in the geriatric population.

13. General guidelines to prescribe drugs of elderly are mentioned below:
• Assess the need of drug therapy.
• Select drugs reported to be safe.
• Avoid unsafe drugs.
• Prepare dose and dosing schedule considering status of liver and
renal system.
• Select appropriate formulation that is easy to administered (e.g. liquid
orals are easy compared to large tablets due to reduced salivary secretion.).
• Record drug history carefully before prescriptions.
• Try to reduce number of drugs.
• Use alternative methods like hydrotherapy, massage etc. to a maximum
possible extent.

14. Conclusions:
1) Limit – Range
2) Reduce – Dose
3) Review – Regularly
4) Explain – clearly

15. •References:
• British National Formulary 49 March, 2005.page no 17 to 18
• Text book of basic and clinical pharmacology by Bertram
G.Katzung 6th Edition, page no.923 to 931.
• Text book of general pharmacology by Dr. N. S. Vyawahare
Saloni.Vora page no. 11.1 to 11.7.
• Text book of clinical pharmacy and therapeutics by Rogerwalker
cate whittlesea 4th Edition page no.135 to 138.
•www.wikipedia.com

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