Salsalate is used to treat rheumatoid arthritis and osteoarthritis and is in a class of medications known as non-steroidal anti-inflammatory drugs (NSAIDs).
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. | Folic acid* Potassium* Vitamin C* |
 Avoid: Adverse interaction—Avoid these supplements when taking this medication because taking them together may cause undesirable or dangerous results. | Lithium* White willow* |
| Side effect reduction/prevention | None known |
| Supportive interaction | None known |
| Reduced drug absorption/bioavailability | 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
Folic acid
Salsalate and aspirin produce anti-inflammatory effects after they are converted in the body to salicylic acid. Studies have shown that aspirin can reduce the amount of folic acid in the blood,1 though it is not known whether this change is significant. Controlled studies are needed to determine whether people taking salsalate are at risk for folic acid deficiency.
Lithium
Lithium is a mineral that may be present in some supplements and is also used in large amounts to treat mood disorders such as manic-depression (bipolar disorder). Most NSAIDs inhibit the excretion of lithium from the body, resulting in higher blood levels of the mineral, though sulindac may have an opposite effect.2 Since major changes in lithium blood levels can produce unwanted side effects or interfere with its efficacy, NSAIDs should be used with caution, and only under medical supervision, in people taking lithium supplements.
Potassium
Salsalate and aspirin are rapidly converted in the body to salicylic acid. Taking large amounts of aspirin can result in lower than normal blood levels of potassium,3 though it is not known whether this change is significant. Controlled studies are needed to determine whether people taking salsalate are at risk for potassium deficiency.
Vitamin C
Salsalate and aspirin are rapidly converted in the body to salicylic acid. Controlled studies show that taking aspirin increases the elimination of vitamin C from the body and lowers blood levels.4 Further controlled research is needed to determine whether salsalate specifically reduces vitamin C levels and whether people taking the drug are at risk for vitamin C deficiency.
Interactions with Herbs
Willow (Salix alba)
Willow bark contains salicin, which is related to aspirin. Salsalate, salicin, and aspirin produce anti-inflammatory effects after they have been converted to salicylic acid in the body. Taking aspirin at the same time as other salicylate drugs can result in adverse effects, such as ringing in the ears, dizziness, headache, confusion, and diarrhea.5 Though there are no studies specifically investigating an interaction between willow bark and salsalate, people taking salsalate should probably avoid using the herb until more information is available.
Interactions with Foods and Other Compounds
Food
Taking salsalate with food can slow the speed of absorption but not the overall amount of drug absorbed;6 therefore, it can be taken with a meal, if needed, to avoid stomach upset.
References
1. Alter HJ, Zvaifler NJ, Rath CE. Interrelationship of rheumatoid arthritis, folic acid and aspirin. Blood 1971;38:405–16.
2. Olin BR, ed. Central Nervous System Drugs, Analgesics and Anti-inflammatory Drugs, Nonsteroidal Anti-inflammatory Agents, In Drug Facts and Comparisons. St. Louis, MO: Facts and Comparisons, 1993, 1172–90.
3. Smith MJH, Smith PK, eds. The Salicylates: A Critical Bibliographic Review. New York: Interscience, 1966.
4. Loh HS, Watters K, Wilson CWM. The effects of aspirin on the metabolic availability of ascorbic acid in human beings. J Clin Pharmacol 1974;13:480.
5. Sifton DW, ed. Physicians Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 1661–2.
6. Sifton DW, ed. Physicians Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 1661–2.
Copyright 2007, Healthnotes, Inc., 1505 S.E. Gideon St., Suite 200, Portland, Oregon 97202, www.Healthnotes.com.
2006-09-07
