Risedronate is used to treat Paget’s disease of the bone, and is in a family of drugs
known as bisphosphonates.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
 May Be Beneficial: Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them. |
Calcium*
|
Avoid: Reduced drug absorption/bioavailability—Avoid these supplements
when taking this medication since the supplement may decrease the absorption and/or activity
of the medication in the body. |
Antacids
Calcium
Food
Iron
Magnesium
Zinc (absorption)
Zinc (action)
|
| Side effect reduction/prevention |
None known
|
| Supportive interaction |
None known
|
| Adverse interaction |
None known
|
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
evidence.
Interactions with Dietary Supplements
Calcium and Vitamin D
Short-term treatment with risedronate in people with hyperparathydoidism—a disorder
characterized by high blood levels of calcium—resulted in lower calcium blood
levels.1 Additional research is needed to determine whether people taking
risedronate for Paget’s disease might develop low blood calcium levels. As a precaution,
people with Paget’s disease should take supplemental calcium and vitamin D if dietary
intake is inadequate. However, taking risedronate at the same time as calcium supplements
reduces absorption of the drug.2 Therefore, people taking risedronate for
Paget’s disease should take calcium supplements an hour before or two hours after taking
the drug.
Minerals
Taking risedronate at the same time as iron,
zinc, or magnesium may reduce the amount of drug
absorbed.3 Therefore, people taking risedronate who wish to supplement with these
minerals should take them an hour before or two hours after the drug.
Interactions with Foods and Other Compounds
Antacids
Taking risedronate at the same time as antacids containing calcium or magnesium may reduce absorption of the drug.
Therefore, people taking risedronate should take calcium- or magnesium-containing antacids an
hour before or two hours after the drug.
Food
One controlled study showed that taking risedronate either a half an hour before or two hours
after a meal dramatically reduced absorption of the drug, compared with taking the drug one
hour before or four hours after a meal.4 Consequently, people should take
risedronate one hour before a meal or 4 hours after a meal, as long as the latter is at least
one hour before the next meal.
References:1. Reasner CA, Stone MD, Hosking DJ, et al. Acute changes in calcium
homeostasis during treatment of primary hyperparathyroidism with risedronate. J Clin
Endocrinol Metab 1993;77:1067–71.
2. Sifton DW, ed. Physicians’ Desk Reference. Montvale,
NJ: Medical Economics Company, Inc., 2000, 2504–6.
3. Sifton DW, ed. Physicians’ Desk Reference. Montvale,
NJ: Medical Economics Company, Inc. 2000, 2504–6.
4. Mitchell DY, Heise MA, Pallone KA, et al. The effect of dosing regimen
on the pharmacokinetics of risedronate. Br J Clin Pharmacol 1999;48:536–42.