OS-08 Three Adverse Drug Interactions That Every Endodontist Should Know About

CE Hours: 1.0

Description: This presentation will focus on two areas.  1) Serious adverse drug interactions that may occur in the Endodontic Patient because of drugs that he/she prescribes or administers and 2) Serious adverse drug interactions that may occur in the endodontist himself/herself because of drugs that they are taking for various medical conditions. The three serious drug interactions that may adversely affect the dental patient include; 1) the ability of the antimicrobials metronidazole and fluconazole to inhibit the metabolism of warfarin by blocking cytochrome P-450 2C9 (CYP-2C9), the major metabolic pathway of warfarin, resulting in dramatic increases in patients' international normalized ratios (INRs) and potentially fatal bleeding. 2) The ability of ibuprofen or naproxen sodium to inhibit the renal excretion of the major bipolar disorder drug lithium resulting in tremors, seizures and renal toxicity. 3) The ability of propranolol and other nonselective beta-adrenergic blocking agents to inhibit the vasodilatory effect of epinephrine in dental local anesthetic solutions, leading to severe hypertensive reactions and a concomitant reflex bradycardia. Interactions relevant to the health of dentists themselves include the ability of grapefruit juice/grapefruit to elevate blood levels of statin cholesterol lowering drugs, increasing the risk of myalgia, rhabdomyolysis and acute renal failure.  It is important for clinicians to understand the theoretical basis behind these often-predictable interactions, and comprehend the evidenced-based-science that supports their existence.

Learning Objectives:  

• Discuss the pharmacological mechanism behind the potentially lethal metronidazole or fluconazole/warfarin interaction.
• Discuss the rationale of why recommending ibuprofen (Advil®) and naproxen sodium (Aleve®) for pain control is a bad idea in a bipolar disorder patient taking lithium (Eskalith®).
• Identify which class of anti-hypertensive drugs where high doses but therapeutic doses of local anesthetic plus epinephrine is most likely to cause a a pressor response with a reflex bradycardia.