About My-Rx Check

Where the information comes from

The information is provided by the U.S. National Library of Medicine (NLM), part of the National Institutes of Health:

• DailyMed — the full text of each drug's FDA-approved label: boxed warning, contraindications, drug interactions, warnings and laboratory tests.
• RxNorm — drug names, strengths and active ingredients.
• RxClass / MED-RT — drug classes, and the diseases a drug is contraindicated with.
• Clinical Table Search Service — drug-name and ICD-10-CM condition search.
• MedlinePlus — plain-language pages linked from each medication.

Supplement products and their ingredients come from the NIH Office of Dietary Supplements' Dietary Supplement Label Database. The NLM and NIH do not endorse this product. Each source, and when it was last updated, is listed on the Reference tables page.

Updated automatically

Nobody re-types or hand-edits the drug data. The checker requests it directly from the NLM's public services, and a stored copy is used for at most 30 days (searches: 7 days) before it is requested again automatically. When a manufacturer revises a label and DailyMed publishes the new version, the checker picks it up on its next request.

Every month the checker is also re-run automatically against a set of drug pairs and combinations whose answers are known and referenced, and DailyMed's version history is checked for revised labels. Any change in the results is reviewed.

How the relationships are found

The checker reports four kinds of relationship between the items on your list:

• Drug to drug — one drug's label mentions another drug on your list, its active ingredient, or its drug class.
• Drug to supplement — a drug's label mentions a supplement ingredient on your list.
• Drug to condition — a drug's contraindications or warnings use the terms for a condition on your list, or MED-RT lists the condition as one the drug is contraindicated with.
• Drug to lab result — a lab value outside its typical range, and a drug's label uses the words for that abnormality.

These relationships are discovered by pattern matching across the source data: the checker searches the label text and NLM relationships for the names, ingredients, classes and terms on your list. They are not necessarily driven by any particular context of interest. A match means the source text mentions the pairing. It does not mean the passage applies to your dose, age, condition or circumstances. And because a label may word an interaction differently, no finding does not mean no interaction.

The tables behind the condition, lab and multi-drug cross-checks are published in full on the Reference tables page.

Who makes it

My-Rx Check is built and maintained by SoftLOGiX, Inc. Questions, corrections and suggestions are welcome on the Contact page.

Educational information only — not medical advice, diagnosis or treatment. Never start, stop or change a medication because of what you see here; talk to a licensed professional first. See the Terms of Service.