Recognizing high-risk patients for drug interactions is crucial in Emergency Medicine.
Drug interactions can lead to a range of presentations from syncope to altered alertness.
Avoiding specific drug combinations in renal patients can prevent hyperkalemia and toxicity.
Practicing caution in prescribing medications known to interact is vital for patient safety.
Deep dives
Drug Interactions in Emergency Medicine
30% of ED patients have at least one drug-related problem contributing to their ED visit, with adverse drug reactions and subtherapeutic dosing being common triggers. Over 1 in 9 ED visits result from drug-related adverse events, often due to preventable drug interactions. Drug interactions can lead to presentations like syncope, delirium, falls, and altered level of alertness. Recognizing and avoiding drugs that interact to prevent adverse outcomes is crucial.
Identifying High-Risk Patients for Drug Interactions
Older patients, those with renal issues, cardiac conditions, and mental health problems are at higher risk for drug interactions. Fragile patients, multiple comorbidity, and multiple drug use increase the likelihood of drug interactions. In situations where presentations are unexplained, considering drug interactions can be key to accurate diagnosis and management.
Common Interactions and Risks in Renal Patients
In renal patients, hyperkalemia is a significant concern with drugs like ACE inhibitors, trimethoprim, NSAIDs, and heparin. Medications like DOACs, digoxin, and colchicine can lead to toxicity due to impaired renal clearance. Phosphate binders like calcium can inhibit other drug absorption, such as quinolones, tetracyclines, and thyroxine.
Antimicrobials and Cardiovascular Drugs Interactions
Caution is advised when combining ACE inhibitors, ARBs with trimethoprim, as it can lead to hyperkalemia. Macrolides like erythromycin can interact with ALS statins, increasing the risk of rhabdomyolysis. Macrolides can also inhibit CYP3A4, affecting drugs like calcium channel blockers, potentially leading to syncope and hypotension.
Case Study on Drug Interactions
A patient on sertraline and ceterazine developed adverse effects after receiving fentanyl and propofol during procedural sedation, indicative of serotonin syndrome. Other examples discussed include statins with quinolones and macrolides leading to rhabdomyolysis, and calcium channel blockers interacting with macrolides causing hypotension and syncope.
Mitigating Drug Interactions
Understanding the risks and common interactions of drugs in various patient populations is essential for preventing adverse outcomes. Practicing caution and awareness when prescribing medications known to interact can help in avoiding potential harm. Regular monitoring and analysis of patient responses to drug combinations are vital in ensuring safe and effective treatment.
Macrolides and Drug Interactions
Macrolides like azithromycin are highlighted as safer options among antibiotics in terms of drug interactions compared to others like erythromycin and clarithromycin. The interaction of macrolides with certain statins and calcium channel blockers can lead to hypotension and rhabdo. Notably, azithromycin does not inhibit SIP 3A4, reducing the risk of adverse effects such as hypotension and rhabdo.
NSAIDs and Potential Interactions
NSAIDs, commonly used in the emergency department, pose risks when combined with other medications. NSAIDs can interact with aspirin, causing increased risk of gastrointestinal bleeding. They can also impact renal function, especially when combined with diuretics or multiple cardiovascular drugs. Ibuprofen and naproxen are considered safer options for short-term NSAID use due to their lesser interaction potential.
We miss potentially dangerous and even lethal drug interactions in EM more often than we realize. In this main episode EM Cases podcast with Dr. David Juurlink and Dr. Walter Himmel we review the common categories of drugs, the high risk patients and the key drug interactions that we need to know about in Emergency Medicine...
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