What steps can be taken to minimize the risk of drug interactions in an adult patient with a history of chronic illness, such as hypertension, diabetes, or hyperlipidemia, who is taking multiple medications, including prescription and over-the-counter drugs?

Minimizing Drug Interaction Risk in Adults with Chronic Illness on Multiple Medications

Implement a systematic, team-based medication review process that prioritizes identification and deprescribing of high-risk medications, particularly benzodiazepines, opioids, and drugs with anticholinergic properties, while maintaining a comprehensive list of all prescription, over-the-counter, and herbal medications to screen for clinically significant interactions. 1

Establish a Comprehensive Medication Inventory

• Document every medication the patient takes, including prescription drugs, over-the-counter medications, vitamins, dietary supplements, and herbal products 2
• More than 60% of patients with cardiovascular disease combine complementary/alternative medications with prescription drugs, and only 5% of over-the-counter medications appear in patient charts 1
• Patients often fail to notify providers about unconventional medication use, and physicians may not routinely ask, leading to missed serious adverse drug reactions 1
• Maintain a single, updated medication list that patients bring to every healthcare encounter and share with all prescribers and pharmacists 2

Conduct Systematic Medication Reviews

Utilize a trained clinical pharmacist to perform comprehensive medication reviews at regular intervals, focusing on drug therapy problems, interactions, and appropriateness 1

• Review each medication for: current indication, history of adverse effects, therapeutic duplication, inappropriate dose/route/schedule, current adverse effects, drug-drug interactions, and drug-disease interactions 3
• Patients taking 5 or more medications average 1 significant drug problem, with risk of adverse drug reactions rising from 13% with 2 medications to 58% with 5 medications 1
• The risk of falls increases by 21% in patients taking 4 or more medications and by 50% in those taking 10 or more medications 1
• Prioritize medication reviews during care transitions (hospital admission, discharge, intensive care transfer) when medication appropriateness must be reevaluated 1

Identify and Target High-Risk Medications

Focus deprescribing efforts on medications with the highest risk profiles: benzodiazepines, opioids, sedative-hypnotics, anticholinergics, and drugs with narrow therapeutic indices 1

• Benzodiazepines are high-risk medications requiring monitoring, with risk that may outweigh benefit, particularly with chronic use 1
• Drugs with narrow therapeutic ranges (warfarin, digoxin, anticoagulants, antiepileptics, hypoglycemics) are more likely to be involved in serious drug interactions 1, 4
• More than 80% of serious adverse drug reactions are type A reactions (dose-dependent, predictable, and potentially avoidable) 1
• Start pharmacological treatment at low doses and gradually titrate upward based on clinical response and adverse drug reactions 1

Screen for Specific High-Risk Drug Interactions

Pay particular attention to common precipitant drugs that modify other medications' absorption, distribution, metabolism, or excretion 4

• Nonsteroidal anti-inflammatory drugs, antibiotics (especially rifampin), and certain cardiovascular medications are common precipitant drugs in primary care 4
• Atorvastatin and other statins interact with cyclosporine, gemfibrozil, macrolide antibiotics, azole antifungals, digoxin, colchicine, fibrates, and multiple antiretroviral medications 2
• Avoid consuming more than 1.2 liters of grapefruit juice daily when taking statins, as this increases risk of muscle problems 2
• Cardiovascular drugs most commonly associated with adverse drug reaction-related hospitalizations include beta-blockers, anticoagulants, digoxin, ACE inhibitors, calcium channel blockers, and oral glucose-lowering drugs 1

Adjust for Age-Related Pharmacokinetic Changes

Account for declining renal clearance and altered pharmacodynamics in older adults by adjusting doses of renally cleared medications 1

• Laboratory-reported kidney clearance estimates should be systematically incorporated within prescribing systems to optimize medication safety 1
• Adjust doses of antibiotics, digoxin, anticoagulants, and hypoglycemics based on declining clearance to avoid toxicity 1
• Older adults have heightened sensitivities to opioids, benzodiazepines, and drugs with anticholinergic properties, resulting in increased toxicity risk 1
• Age explains up to 40% of the variance in warfarin dosing requirements 1

Prevent Prescribing Cascades

Recognize when new symptoms may represent adverse drug reactions rather than new medical conditions requiring additional medications 1

• The prescribing cascade occurs when adverse drug effects are misidentified as new medical conditions, leading to additional prescriptions 1
• Common examples include: prescribing antihypertensives for NSAID-induced hypertension, or NSAIDs/acetaminophen for statin-induced myalgias 1
• Before adding a new medication, systematically evaluate whether current symptoms could be caused by existing medications 1

Utilize Technology and Resources

Employ regularly updated drug interaction databases, automated alerts, and clinical decision support tools to identify potential interactions 5, 6, 7

• Free online drug interaction checkers can categorize interactions into mild, moderate, and severe categories 6
• Pharmacodynamic interactions (80.2%) are more prevalent than pharmacokinetic interactions, mainly occurring with psychiatric/seizure/sleep disorder medications and pain medications 5
• Combining human expertise with technological solutions such as automated drug interaction alerts improves medication safety 6
• Consult with pharmacists as an excellent resource for determining appropriate dosages, potential interactions, and overlapping drugs 3

Simplify Medication Regimens

Reduce regimen complexity by consolidating to once or twice daily dosing whenever possible and eliminating medications without clear benefit 1

• Simplifying regimens in ambulatory patients and long-term care reduces hospitalizations and negative incidents 1
• Ongoing comprehensive medication reviews and medication management support result in fewer hospitalizations 1
• Medication management interventions (reminder systems, education) improve adherence, though effects vary 1
• Concordance between clinician and patient leads to greater motivation, persistence, and adherence 1

Monitor for Adverse Drug Reactions

Establish regular monitoring protocols for patients on high-risk medications, particularly those requiring laboratory surveillance 1

• Patients taking drugs requiring regular monitoring (antiplatelets, antiarrhythmics, digoxin, glucose-lowering drugs, diuretics, ACE inhibitors, ARBs, warfarin) are at increased risk of adverse drug reactions 1
• Healthcare provider should perform blood tests to check liver function before starting statins and if symptoms of liver problems develop 2
• Report unexplained muscle pain, tenderness, or weakness immediately, especially if accompanied by fever or unusual fatigue, as this may indicate serious muscle breakdown 2

Address Multiple Prescribers and Pharmacies

Coordinate care across multiple providers by ensuring shared medication records and integrated prescription systems 1

• Segmented healthcare with multiple providers who lack shared records results in duplicative or interacting treatments prescribed naively 1
• Unless pharmacies share integrated prescription records, pharmacists remain unaware of duplicates or interacting medications 1
• Encourage patients to use a single pharmacy whenever possible to facilitate comprehensive interaction screening 1