Please enable JavaScript.
Coggle requires JavaScript to display documents.
Geriatric Pharmacology - Coggle Diagram
Geriatric Pharmacology
1. Physiological Changes with Age (Pharmacokinetics & Pharmacodynamics)
Absorption: Slower stomach emptying and higher stomach pH can delay the absorption of specific items like iron and calcium.
Distribution: Older adults have more body fat, which causes fat-soluble (lipophilic) drugs like diazepam to stay in the body longer. They have less body water and less albumin protein, which raises the blood concentration and active levels of water-soluble drugs, increasing toxicity risks.
Metabolism: The liver decreases in size and blood flow, which slows down Phase I drug breakdown (such as for the drug propranolol).
Excretion: Kidney function declines significantly, which extends a drug's half-life and increases the risk of dangerous drug accumulation.
Sensitivity: Older bodies have a naturally heightened sensitivity to medications like benzodiazepines and opioids, and are more prone to low blood pressure (hypotension) due to weaker baroreceptor reflexes.
2. Common Pharmacological Challenges
A. Polypharmacy
Definition: The routine use of multiple medications by a single patient, usually ranging from 3 to 9 or more concurrent drugs.
Risks & Causes: Driven by having multiple chronic health conditions, seeing several different doctors, using multiple pharmacies, taking over-the-counter supplements, or prescribing new drugs just to treat the side effects of old ones.
Consequences: Leads to dangerous side effects, confusion, drug interactions, higher healthcare costs, and "Geriatric Syndromes" like falls, memory issues, and urinary incontinence.
Prevention Rule: Review medications regularly, use non-drug options when possible, and strictly follow the golden rule: "Start low, go slow, and know when to stop."
B. Drug Interactions
Drug-Drug: Medications changing how other drugs work (e.g., Warfarin + NSAIDs increases bleeding; Benzodiazepines + Opioids increases sedation and falls).
Drug-Food: Foods altering drug processing (e.g., Grapefruit juice blocks the CYP3A4 enzyme, raising drug levels in the blood).
Drug-Supplement: Herbs disrupting prescription plans (e.g., St. John's Wort lowers how well warfarin works).
Why Elders are at Risk: They take more drugs (polypharmacy) and have a reduced homeostatic reserve, meaning their bodies cannot easily self-regulate or bounce back from an adverse reaction. Doctors should check guidelines like the Beers Criteria and STOPP/START to minimize these risks.
C. Adverse Drug Reactions (ADRs)
Definition: Harmful, unintended responses to medications that happen at normal, regular doses.
Common Forms: Falls/fractures (from sedatives or blood pressure drugs), central nervous system issues like delirium or confusion (from anticholinergics or opioids), stomach bleeding (from NSAIDs), and electrolyte imbalances (from diuretics).
D. Medication Adherence (Taking Pills Correctly)
Barriers to Adherence: Forgetfulness, complicated multi-drug schedules, physical trouble opening bottles or seeing labels, high costs, and a lack of understanding.
Solutions to Improve Adherence: Simplify the drug schedule (such as switching to once-daily dosing), use daily pill organizers, utilize alarms or apps, and provide clear patient and caregiver education.