Drug interactions represent a significant threat to the wellbeing of patients. As part of their commitment to helping patients safely and effectively manage their medications, clinicians should discuss drug interactions whenever modifying patients' medication regimens.
Here are seven topics clinicians will want to address during these conversations.
1. Drug Interaction Risks
Any discussion about drug interactions should begin with an introduction or review of the potential interactions associated with a drug. This will help patients appreciate the importance of the information that will be covered during the conversation.
Drug interactions can potentiate a medication's effects, possibly triggering a response similar to that of an overdose, or reduce a medication's effects, possibly to the point where the medication is entirely ineffective.
2. Types of Drug Interaction Risks
There are a few different types of drug interactions, all of which are worth reviewing with patients.
Drug-drug interactions occur when two or more medications — prescription and/or over-the-counter (OTC) — react with one another and produce results such as those described above. For example, the U.S. Food & Drug Administration notes that mixing a sedative and antihistamine can slow people's reactions, thus making driving a car or operating machinery more dangerous, while cold medications containing a decongestant can raise one's blood pressure, which may be particularly harmful for patients with high blood pressure.
Drug-food interactions occur when a food or drink interferes with a medication. A Harvard Health Publishing report notes, "Several foods can also block or stimulate the enzymes that break down drugs. People who wash down atorvastatin (Lipitor) or simvastatin (Zocor) with large amounts of grapefruit juice may experience muscle pain and other side effects from statin 'overdose,' because the juice inhibits the enzyme that clears the statins. Fish oil supplements can have a similar effect when taken with warfarin, increasing the risk of severe bleeding. Iron supplements can diminish the effects of levoxythyroxine (Synthroid), the medication used to treat an underactive thyroid."
Finally, there's adverse drug reactions. Much less predictable but still important to address with patients, this interaction occurs when the body has an unexpected reaction to a medication for reasons that include the presence of certain enzymes, metabolism rate, and existing conditions and diseases.
3. Patient-Specific Risks
Whenever modifying a regimen, determine whether any of the patient's medications is associated with documented interactions, such as those discussed above, and advise the patient on what they should and should not do to avoid increasing the risk of a drug interaction. Include in your discussion advice concerning food, drink, OTC medications, and supplements.
4. Medication Labels
Emphasize the importance of patients carefully reviewing the labels of all medications. Review the types of information on labels that can help patients reduce their drug interaction risks, including the warnings and directions sections as well as an "other information" section that would cover details about ingredients that may be important for specific conditions. Patients should be reminded to review labels frequently, even for those medications they have been taking for an extended period, as labels change when new information becomes available.
5. Other Fundamental Best Practices
There's never a bad time to go over essential medication best practices that can help keep patients safe from potential risks such as drug interactions. These practices include strictly following the medication regimen; filling prescriptions at the same pharmacy, whenever possible; avoiding alcohol; and the importance of speaking with clinicians and pharmacists whenever patients have any questions or concerns regarding a medication or their regimen.
We briefly mentioned supplements earlier, but they are worthy of additional discussion. As an American Family Physician article notes, "Nearly 25% of U.S. adults report concurrently taking a prescription medication with a dietary supplement."
Why is this statistic important? As the Harvard article referenced above notes, "Some of the most serious drug interactions involve prescription medications and supplements. Not only are supplements less likely than FDA-approved medications to be listed in the databases of drug interactions, but healthcare providers also may not know what supplements people are taking."
Clinicians would be wise to review what is classified as a dietary supplement (e.g., vitamins, minerals, herbals and botanicals, amino acids, enzymes) and ask patients to discuss their supplement use. Unless a supplement has been prescribed, clinicians should advise patients to avoid them altogether.
7. Responding to a Drug-Interaction
Clinicians should explain to patients what to do if they believe they are experiencing a drug interaction. Advice should cover how to respond to everything from a mild reaction (e.g., skin rash, cough, itching) to severe reaction (e.g., trouble breathing, confusion, bleeding), which may require a visit to an emergency room. Patients should be advised to contact their clinician when they experience a symptom of an adverse drug reaction to see if a regimen modification is required.