AUDE 6120 Lecture 8: Special Populations & Polypharmacy

Review of Adult Medical History

• Core purpose: context for hearing loss and auditory symptoms; informs diagnosis and management across the patient journey.
• Benefits:
  • Accurate Diagnosis: helps differentiate etiologies; prior head trauma, chronic ear disease, noise exposure, surgeries point to specific causes; improves diagnostic accuracy. $1$
  • Identification of red flags requiring medical referral: sudden/rapid onset, pain or drainage, unilateral loss, unilateral or recent-onset tinnitus, vertigo, tumor history. $4$
  • Personalized and effective treatment planning: medication review (ototoxic drugs risk), comorbidity management (cardiovascular/diabetes affecting inner ear perfusion), lifestyle factors (occupation, smoking, recreational activities) for counseling and risk assessment. $5$
• Other factors to consider:
  • Establishing medical necessity for services; thorough documentation.
  • Building patient rapport and trust by addressing patient’s primary concerns first.
  • Legal/ethical responsibility: accurate records essential for defense in complications or malpractice claims.

Review of Child Medical History

• Child hearing closely linked to development; history helps identify causes, progression risk, and comorbidities.
• Key areas of inquiry:
  • Family History: childhood-onset hearing loss tendency.
  • Pregnancy/Birth: complications, prematurity, jaundice with transfusion, normal pregnancy status.
  • Early Childhood: newborn hearing screening, number and treatment of ear infections, meningitis or high fevers.
  • Developmental Milestones: motor, speech, language milestones and current concerns.
  • Medical Conditions: genetic/syndromic associations (e.g., Down’s, Usher’s) and ototoxic medications.

Patient Confidentiality

• Medical history contains personal information; protect privacy during review.
• Consider: who is in the room, who can overhear, who has chart access, patient designation.
• HIPAA rules: only designated individuals (excluding third-party payers/referring pros) may access medical information without consent.

Special Populations and Drug Metabolism

• Patient factors affecting adverse drug reactions (ADRs) in auditory-vestibular system: age, pregnancy/lactation, diet/environment, diseases, preexisting auditory/vestibular conditions, pharmacogenomics, metabolic interactions (polypharmacy).

Age

• Children: most phase I liver reactions mature slowly; dosing by weight is essential; neonatal phase I/II enzymes mature over first $2$ weeks and beyond.

• Neonatal jaundice: UDP-GT enzyme deficiency; risk of drug toxicity with immature metabolism.

• Older adults: reduced metabolic capacity due to liver mass decrease, decreased hepatic blood flow, and CYP enzyme activity changes; phase II pathways more preserved.

• Dosing: may need lowering; CNS side effects (dizziness, disorientation, drowsiness) more common with high doses.

Pregnancy

• Primary concern: teratogenicity; risky fetal impact particularly in the $1^{st}$ trimester.
• Placental barrier not a strong shield for many drugs; avoid drug exposure when possible.

Lactation

• Drug transfer to breast milk; typical transfer ~$1$–2 ext{%} of maternal dose; infant risk usually low but some drugs are contraindicated: lithium, many chemotherapeutics, radioactive compounds, certain antibiotics.

Diet and Environment

• CYP450 modulation by diet/environment (e.g., grapefruit juice inhibits $CYP3A4$ in gut, reducing first-pass metabolism for substrates of $CYP3A4$; may raise systemic exposure for calcium-channel blockers and statins).
• Environmental pollutants (cigarette smoke, petroleum products) affect phase I/II enzymes and metabolism.

Liver Disease

• Liver enzymes critical for drug metabolism; disease slows metabolism, increasing active drug concentrations and toxicity risk.
• Examples: hepatitis, cirrhosis, cancer, fatty liver, hemochromatosis.
• Dose reductions often required; comorbidity with cardiac disease can further alter hepatic delivery.
• Thyroid hormones influence metabolic rate and thus drug metabolism (hyperthyroid speeds, hypo slows).

Renal Disease

• Kidney elimination of most drugs; renal impairment risks accumulation/toxicity if not adjusted.
• Altered pharmacokinetics: bioavailability, protein binding, volume of distribution.

Patient Factors Related to Compliance

• Compliance: extent to which patient behavior aligns with medical advice.
• Definition: alignment between actual dosing history and prescribed therapy.
• Key idea: treatment effectiveness depends on patient motivation and ability to follow regimen.

Noncompliance

• A multidimensional issue impacting chronic disease management; affects audiology (hearing aids use, tinnitus/vestibular therapy adherence).
• WHO defines noncompliance as interplay of five sets of factors: $5$ sets of factors (patient-related, condition-related, therapy-related, health system factors, social factors).
• Typical noncompliance range: $20\%$–$80\%$ depending on treatment; average around $50\%$.
• Higher noncompliance with complicated regimens; injections and lifestyle changes often show lower adherence.
• Compliance can fluctuate over time with symptom severity and treatment side effects.

Noncompliance: Types and Examples

• Prolonged intervals between doses (drug holidays or lapses > $3$ days).
• Nonpersistence: stopping medication altogether.
• White coat compliance: good adherence around visits but poor otherwise.
• Diagnostic/therapeutic confusion can occur due to irregular adherence.

Factors Affecting Compliance

• Parents/caregivers; family beliefs about meds and benefits.
• Illness type: slightly lower compliance for acute illnesses (e.g., otitis media), higher for chronic diseases (e.g., hypertension, diabetes).
• Cognitive and psychological factors: memory, comprehension, literacy, fear of needles, depression.
• Physical factors: dexterity, vision; ability to swallow pills.
• Cost and access to healthcare.

Improving Compliance

• Education for patients, families, and caregivers.
• Training providers to recognize barriers and adapt instructions.
• Clear, accessible instructions (large print as needed); address dexterity issues.
• Ensure effective communication across care providers.

Metabolic Drug Interactions – Polypharmacy

• Polypharmacy definition (CDC): taking $5$ or more medications concurrently.
• Appropriate polypharmacy: necessary for complex conditions (e.g., transplant patients with multiple supportive meds).
• Inappropriate polypharmacy: unnecessary or duplicative therapies or those causing adverse events.

Polypharmacy: Prevalence and Risks

• Growing issue, especially in the elderly and those with multiple chronic illnesses.
• Risks rise when multiple providers prescribe independently; can lead to drug-drug and drug-disease interactions and prescription cascades.
• Prescription cascade: side effects of one drug misdiagnosed as another condition, leading to more drugs.

Over-the-Counter Medications and Supplements

• OTC use rising, especially among elderly; under-reporting to providers is common.
• Common OTCs: analgesics, laxatives, vitamins, dietary supplements; FDA regulation for supplements is limited.
• Risks include herb-drug interactions and undisclosed combinations with prescribed meds.

Four Basic Mechanisms of Drug Interactions

• Additive and synergistic effects: overlapping pharmacodynamic actions.
• Metabolic effects: induction or inhibition of CYP enzymes altering drug levels.
• Absorption effects: changes in gastric pH or binding affecting bioavailability.
• Displacement from plasma proteins: more free drug in circulation.

Consequences and Risks of Polypharmacy

• Adverse Drug Events (ADEs) increase with each added medication.
• Increased healthcare costs (prescriptions, visits, falls, cognitive decline, hospitalizations).
• Reduced quality of life due to side effects (drowsiness, dizziness, confusion).

Examples of Adverse Drug Interactions

• Aminoglycoside antibiotics + furosemide: enhanced ototoxicity and nephrotoxicity, especially IV.
• Cardiovascular drugs: high involvement in drug interactions; may cause delirium, renal failure, hypotension.
• CNS-active meds: risk of falls and functional impairment (driving, ambulation).

Tools and Strategies for Management

• Brown Bag Medication Review: bring all meds to each appointment to compile accurate lists.
• Deprescribing: planned reduction/cessation of medications no longer beneficial or harmful; shared decision-making.
• Medication Reconciliation: formal process to create the most accurate medication list and compare to current orders, crucial during transitions of care.

Additional Management Strategies

• Use of a Single Pharmacy: centralize prescriptions to enable monitoring for interactions.
• Patient Education: empower questions like "Why am I taking this?", side effects, alternatives.
• Interdisciplinary Teamwork: collaborate with physicians, pharmacists, nurses for coordinated care.