Health Guide

Elderly at Risk of Supplement-Prescription Drug Interactions

The popularity of herbal supplements is growing fast across all age groups. Elderly patients often take herbal remedies to improve heart health, reduce joint pain or improve sleep. Not all herbal supplements are safe for use by elderly patients when prescription medications are required for improved health. Some interactions between herbal supplements and prescription medications can be deadly.

Herbal laxatives may reduce absorption of prescription medications. When bowel movements go awry, many elderly people choose to take herbal colon cleansers or laxatives to improve regularity. The most common over-the-counter treatment for constipation is fiber, sold under the brand names Metamucil, Benefiber, Fibercon and other brand names. Herbal laxatives are also available in stimulant varieties.

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Stimulant laxatives cause the muscles of the bowel to contract, forcing waste to move through the intestine faster. Both stimulant and non-stimulant herbal laxatives decrease the time waste spends in the intestine and thus, decrease the time prescription medications have to absorb through intestinal walls.

To avoid the interaction between fiber, laxatives and prescription medications, elderly must take the prescription medications at least one hour before or two hours after taking fiber.

Licorice root may increase the effectiveness of prescription medications. Licorice root often appears in herbal supplements for stomach upset and constipation. There are known interactions between licorice root and diuretics, Digoxin, corticosteroids and insulin, but it is the unknown interactions that could be dangerous for the elderly.

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Some diuretics like Esidrix and Zarolxolyn are commonly prescribed to lower blood pressure. Elderly patients may not know these drugs are diuretics. When licorice root is taken with diuretics, it may increase the effectiveness of the medication or increase the side effects associated with the prescription medication.

To reduce the risk of possible interaction between licorice root and prescription medications, ask your doctor if the blood pressure medication you’re taking is also a diuretic.

Check the label on the herbal supplements you’re taking for the ingredient licorice root. There is no safe way to combine the two treatments. Licorice root should not be taken with diuretics at any time.

Herbal supplement ingredients may cause dangerous side effects during surgery. Many elderly people believe the word herbal or all-natural means safe, but that is not always the case.

Common herbal remedies may pose potentially dangerous and life-threatening side effects when taken with certain medications given before, during and after surgery.


Garlic, commonly used to improve heart health, is generally considered safe, but when garlic is taken with anti-clotting and immunosuppressant medications, serious interactions may occur.

Garlic is known to interact with Warfarin, Plavix, dipyridamole and indomethacin. Garlic is not the only herbal supplement known to interact with blood thinners like Warfarin. Others include feverfew, ginger, St. John’s Wort and cranberry.

Interactions between anesthesia, transplant drugs and herbal supplements also occur. Valerian root, commonly used to improve sleep and St. John’s Wort, commonly used as a natural treatment for depression, may interact with anesthetic and immunosuppressant drugs, respectively.

To avoid possible interactions between herbal supplements and prescription medications used before, during and after surgery, reveal all treatments, both over the counter and prescription, to the surgeon performing the procedure and the anesthesiologist.

It is typically advised to stop taking all herbal remedies at least two weeks before surgery to prevent possible interaction.

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As the body ages, the elderly may choose alternative therapies to treat depression and pain or improve heart health. Many of these herbal supplements are safe, but when taken with prescription medications may cause serious side effects and interactions.

It is best to talk with your prescribing physician about any herbal supplements currently part of your daily routine.