Exploring drug-nutrient interactions

Drug-nutrient interactions can impact absorption and metabolism of both the medication and specific nutrients. There is a lot to consider when it comes to making informed decisions on what to eat when taking certain medications, so it’s worth exploring some key points to be proactive in helping to manage your patients’ health. 

Common medications with nutritional impact

Some of the more common medications that carry potential nutritional implications are: 

Antibiotics 

Antibiotics are used to kill bacteria. Unfortunately, they cannot distinguish the good bacteria from the bad. This can lead to killing off “good bacteria” in the gut that is needed for optimal GI health. Disruptions to the microbiome can lead to nutrient deficiency even when a nutritious, balanced diet is consumed. 

Common drug-nutrient interactions:

Due to disrupted gut flora, multiple nutrients are at risk for deficiency, including B vitamins, potassium, biotin, calcium, iron, magnesium, zinc, and vitamin K. 

Blood pressure medications 

There are various types of medications used to treat hypertension. The most common medications are beta-blockers, ACE inhibitors, and calcium channel blockers. Beta-blockers include bisoprolol (Cardicor® or Emcor®), labetalol (Trandate®), and metoprolol (Lopresor®). Common ACE inhibitors include lisinopril (Zestril®) and enalapril (Vasotec®). And amlodipine (Norvasc®), diltiazem (Cardizem®), and nifedipine (Procardia®) are examples of calcium channel blockers.  

Common drug-nutrient interactions: 

With the use of ACE inhibitors, zinc, iron, and potassium depletion can be an issue. Alternatively, beta-blockers have been shown to reduce melatonin production. And potassium depletion is a concern with calcium channel blockers. 

Diuretics 

Diuretics cause increased excretion of urine, which can lead to mineral and electrolyte depletion. Loop diuretics are commonly used to manage fluid overload and include furosemide (Lasix®), bumetanide (Bumex®), spironolactone (Aldactone®), and torsemide (Demadex®). Thiazide diuretics are used to treat hypertension and include hydrochlorothiazide (Aquazide H®, Hydrocot®, and others) and chlorthalidone (Thalitone®).  

Common drug-nutrient interactions: 

Diuretics cause sodium loss in the urine. Magnesium, potassium, and zinc may also be depleted with the use of loop and thiazide diuretics.  

Anti-hyperglycemic drugs are used in the treatment of type 2 diabetes. For many patients, metformin (Glucophage®) is prescribed as first-line treatment depending on the patient’s hemoglobin A1c. Metformin works to lower blood glucose levels by reducing absorption of dietary glucose and the liver’s production of glucose while also increasing insulin sensitivity. 

Common drug-nutrient interactions: 

There is a potential concern that metformin may impact vitamin B12 absorption. The exact reason why is not well-understood, but regular monitoring of B12 levels and possible supplementation may be needed for patients taking metformin long term.  

 Proton pump inhibitors (PPIs) 

PPIs are used to treat heartburn due to increased stomach acid production. PPIs or antacids, as they are commonly known, may increase the risk of low levels of stomach acid, which impairs the body’s ability to digest food properly. Patients can purchase PPIs over the counter or have them prescribed. Some examples include omeprazole (Prilosec®), esomeprazole (Nexium®), and pantoprazole (Protonix®). 

Common drug-nutrient interactions: 

The long-term use of PPIs has been associated with multiple mineral and vitamin deficiencies such as calcium, iron, magnesium, B12, and vitamin C due to the reduction of stomach acid. 

Oral corticosteroids 

Corticosteroids are used to relieve inflammation, pain, and provide immunosuppressant effects in the body. Examples include prednisone and dexamethasone (Decadron®). 

Common drug-nutrient interactions: 

Drug-nutrient interactions become a concern with long-term use of oral corticosteroids. Calcium loss and increased risk for osteoporosis are concerns. Steroids also commonly raise blood glucose levels, which can be of particular concern for individuals with diabetes. 

Identifying nutritional deficiencies

Identifying potential concerns for nutritional deficiency requires a comprehensive approach involving both the patient and their healthcare providers. Regular monitoring is essential and may consist of one or more of the following: 

• Blood tests  
• Review of patient symptoms  
• Diet assessment and evaluation by a registered dietitian  
• Review of medication history 

In addition to regular monitoring, education is important too. Educating patients on the potential medication side effects and drug-nutrient interactions will empower them to play a vital role in their own care.  

Conclusion

Patients need to be educated on the potential nutritional side effects and drug-nutrient interactions of medications they are taking. The first step is communicating these potential drug-nutrient interactions with patients and their caregivers. If a nutrient deficiency arises, patients should be referred to a registered dietitian for more tailored nutrition interventions.  

Dietitians On Demand is a nationwide staffing and recruiting company for registered dietitians, specializing in short-term, temporary and permanent-hire positions in acute care, long-term care and food service positions. We’re dedicated to dietitians and helping them enhance their practice and excel in the workplace. Check out our job openings, request your coverage, or visit our store today!

References: 

Food-Drug Interactions. Available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3191675/. Accessed on 1/9/24. 

Mixing Medications and Dietary Supplements Can Endanger Your Health. Available at https://www.fda.gov/consumers/consumer-updates/mixing-medications-and-dietary-supplements-can-endanger-your-health. Accessed on 1/9/24.  

Drug-Nutrient Interactions. Available at https://extension.okstate.edu/fact-sheets/drug-nutrient-interactions.html. Accessed on 1/9/24. 

Food-Drug Interactions. Available at https://www.hopkinsmedicine.org/health/conditions-and-diseases/fooddrug-interactions. Accessed on 1/9/24. 

Do Medicines Commonly Used by Older Adults Impact their Nutrient Status? Available at https://www.sciencedirect.com/science/article/pii/S2667276621000676. Accessed on 1/9/24. 

Drug-Nutrient Interactions: A Broad View with Implications for Practice. Available at https://www.sciencedirect.com/science/article/abs/pii/S0002822311015446. Accessed on 1/22/24.