What You Need to Know about Potential Drug Interactions

It is imperative for dentists to know the risks of potential interactions of patients’ medication with dental drugs, said speaker Harold Crossley, DMD, at the recent ADA 2016 Meeting in Denver, Colorado.

There is due diligence on the part of the healthcare practitioner to obtain an accurate medication history from a patient. Numerous medications interact with dental drugs or complicate dental procedures, as outlined by Harold Crossley, DDS, PhD, in his presentation on Thursday, October 20 at the American Dental Association’s (ADA) 2016 meeting in Denver, CO. (See Table 1 for some common medications patients may be taking. Note: this list in not all inclusive, and does not include all medications in a particular medication class.)

Important points to consider with respect to antibiotics:

Dr. Crossley also made some important points regarding antibiotics patients may be taking. As practitioners know, some examples in which prophylaxis prior to an invasive dental procedure is necessary, include an artificial heart value, history of infective endocarditis, congenital heart disease, or a cardiac transplantation with a heart valve abnormality. Administer the antibiotics 30-60 minutes prior to the procedure. However, if the patient did not receive antibiotics prior to the procedure, they can be administered up to 2 hours after the procedure and will still provide a fair degree of protection. Appropriate antibiotics include amoxicillin, or if the patient has a penicillin allergy, perhaps cephalexin or clindamycin, azithromycin, or clarithromycin.

Dr. Crossly brought to the audience's attention the fact that if the patient is already taking an antibiotic for another indication, the dentist will need to prescribe an additional antibiotic with a different mechanism of action.

Some examples in which no prophylaxis is needed are mitral valve prolapse, rheumatic heart disease, bicuspid value disease, ventricular septal defect, atrial septal defect, or hypertrophic cardiomyopathy.

Typically, no antibiotic prophylaxis is needed in patients with stents.

Per the ADA, there is no support for routine prophylaxis in patients with joint replacements undergoing dental procedures, unless the person has had a comprising situation in the past with respect to the prosthesis.

The ADA has a position statement on the use of prophylactic antibiotics that can serve as reference for dental practitioners.

TABLE 1: Common Medications & Side Effects

MEDICATION

MECHANISM OF ACTION

COMMENTS/COMMON SIDE EFFECTS

Ibuprofen

NSAID, COX1 and COX2 inhibitor

  • Kidney toxicity possible
  • Only ONE NSAID at a time (aspirin taken for cardioprotection is okay to take with other NSAIDs)
  • Do not administer during pregnancy
  • Similar medications: ketoprofen, meloxicam

Trazodone

Serotonin norepinephrine reuptake inhibitor (SNRI)

  • Caution with vasoconstrictors

Warfarin

Vitamin K antagonist

  • Efficacy measured via International Normalized Ratio (INR)
  • Foods high in vitamin K content can affect INR
  • Many drug-drug interactions: NSAIDs, statins, tetracyclines, metronidazole

Dabigatran etexilate (Pradaxa)

Direct thrombin inhibitor

  • Twice daily dosing
  • Idarucizumab (Praxbind) is the reversal agent

Rivaroxaban (Xarelto)

Direct factor Xa inhibitor

  • Andexanet alfa (AndexXa) is the reversal agent for all Xa inhibitors- NOT FDA APPROVED
  • Similar medications: Apixaban (Eliquis), Endoxaban (Savaysa)

Clopidogrel (Plavix)

Platelet aggregation inhibitor, blocks ADP (P2Y12) receptors on the platelet

  • Prodrug- converted to its active form in the body
  • Drug-drug interactions common
  • Similar medications: Prasugrel (Effient), Ticagrelor (Brilinta)

Duloxetine (Cymbalta)

Serotonin norepinephrine reuptake inhibitor (SNRI)

  • Can also be used for neuropathic pain and various neurological/psychological conditions
  • Caution with vasoconstrictors

Montelukast (Singulair)

Leukotriene receptor antagonist

  • Used in treatment of asthma

Hydrochlorothiazide

Works in kidneys to reduce sodium reabsorption

  • Diuretic and antihypertensive
  • Depletes potassium
  • Photosensitivity- advise patients to wear sunscreen

Fluticasone and salmeterol (Advair)

Steroid with long acting beta agonist

  • Thrush

Amoxicillin

Inhibits cell wall synthesis of certain bacteria

  • Taking amoxicillin and allopurinol together may increase likelihood of a rash

Amolodipine (Norvasc)

Inhibits influx of calcium into vascular smooth muscle and cardiac muscle

  • Gingival hyperplasia
  • Avoid taking concurrently with erythromycin or clarithromycin

Valsartan (Diovan)

Binds to angiotensin receptors to block functions of angiotensin II

  • Can increase potassium

Alprazolam (Xanax)

Binds gamma aminobutyric acid (GABA)

  • Top psychiatric drug prescribed in 2015
  • Dry mouth

Metformin

Improves insulin sensitivity, decreases hepatic glucose production

  • Also used in polycystic ovarian syndrome (POCS)

Gabapentin (Neurontin)

Exact mechanism unknown, structurally related to GABA

  • Used for neuropathic pain, chronic pain, as a mood stabilizer, and anticonvulsant

Oxycodone/Acetaminophen (Percocet)

Opiate and acetaminophen combination, acts on mu receptor

  • Addictive substance
  • Less nausea/vomiting than codeine
  • Schedule II

Sertraline (Zoloft)

Selective serotonin reuptake inhibitor (SSRI)

  • Bruxism
  • Also used chronic/neuropathic pain
  • May cause increased bleeding (minimal)

Fluconazole (Diflucan)

Antifungal

  • Many drug-drug interactions

Mary Lenefsky, PharmD, is a consultant pharmacist and medical writer who specializes in the creation of medical education content for pharmacists, nurses, physicians, and other healthcare providers. She received her Doctor of Pharmacy Degree from the University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences. She then completed two years of post-graduate residency training at Northwestern Memorial Hospital, specializing in the care of the critically ill.