Data Sources
OmniRx draws from three categories of primary sources. We never use user-submitted data, social media posts, or unverified secondary databases as primary references.
When primary sources conflict or are ambiguous, we defer to the most conservative interpretation. If the FDA label says "use with caution," we classify the interaction at a level that communicates that caution to the user.
How Interactions Are Classified
OmniRx uses a four-level severity system for drug interactions. Each level has specific clinical criteria that determine classification.
| Level | Criteria | User Guidance |
|---|---|---|
| None | No documented pharmacokinetic or pharmacodynamic interaction in FDA labeling, DailyMed, or published literature. The two drugs operate through independent metabolic pathways with no known overlap. | No special precautions needed. These medications can generally be taken together safely, though always confirm with your pharmacist. |
| Mild | A minor interaction documented in prescribing information that is unlikely to require dosage adjustment. Typically involves slight changes in absorption timing or minor additive effects. Clinical significance is low. | Generally safe. Your doctor may suggest spacing doses or monitoring for minor side effects. No dosage change typically required. |
| Moderate | A clinically significant interaction documented in FDA labeling. May require dosage adjustment, increased monitoring (blood tests, symptom tracking), or alternative timing. The interaction can alter drug effectiveness or increase side effect risk. | Talk to your doctor or pharmacist. Dosage adjustment or monitoring may be needed. Do not start, stop, or change dosage without consulting your healthcare provider. |
| Severe | A dangerous interaction that the FDA labels as a contraindication or black box warning. Concurrent use can cause serious adverse events including organ damage, life-threatening arrhythmias, serotonin syndrome, or other emergencies. | These medications should generally not be taken together. Contact your doctor immediately if you are currently taking both. Do not stop any medication without medical guidance. |
How Patient Assistance Programs Are Verified
OmniRx maintains a database of manufacturer patient assistance programs (PAPs), state pharmaceutical assistance programs (SPAPs), and federal programs like Medicare Extra Help. Every listing undergoes a three-step verification process.
Step 1: Direct manufacturer confirmation
We verify each PAP by reviewing the manufacturer's official program page. We confirm the program is currently accepting applications, the covered medications have not changed, and the application process matches what we describe on our site.
Step 2: Eligibility criteria validation
Income thresholds, insurance requirements, and residency criteria are verified against the manufacturer's published guidelines. When a program uses Federal Poverty Level (FPL) percentages, we calculate the corresponding dollar amounts using the most recent HHS poverty guidelines.
Step 3: Cross-reference with public databases
We cross-reference our listings against NeedyMeds.org, Medicare.gov, and state health department databases to ensure completeness. If a program appears in public databases but we cannot verify it directly with the manufacturer, we flag it as "unverified" in our listings.
Update Cadence
- Drug interaction database: Reviewed monthly against updated openFDA data. Emergency FDA safety communications trigger updates within 72 hours.
- Patient assistance program listings: Updated quarterly. Manufacturer program changes (eligibility, covered drugs, application process) are reflected within 30 days of announcement.
- Editorial content: Articles are reviewed every six months for accuracy. Year-tagged articles (e.g., "2026 Guide") are updated or replaced at the start of each calendar year.
Affiliate Disclosure
OmniRx earns revenue through display advertising and affiliate relationships with pharmacy comparison sites, including our sister site RxGrab. We never rank medications, pharmacies, or assistance programs based on affiliate relationships. Our interaction classifications are determined exclusively by clinical data. For full details, see our affiliate disclosure.
Limitations
OmniRx is an informational tool, not a clinical decision-making system. Our interaction checker covers documented drug-drug interactions but does not account for your complete medical history, allergies, organ function, genetic factors, or other variables that affect how medications interact in your body. Always consult your doctor or pharmacist before making changes to your medication regimen.
Additional limitations to be aware of:
- Our database covers FDA-approved prescription and over-the-counter medications available in the United States. It does not include compounded medications, investigational drugs, or medications approved only outside the US.
- Drug-food and drug-alcohol interactions are documented where FDA labeling includes them, but our coverage of these interaction types is not comprehensive.
- Patient assistance program eligibility is approximate. Final eligibility determination is made by the program administrator, not by OmniRx.
Corrections Policy
If you identify an error in our interaction data, assistance program listings, or editorial content, please contact us immediately at [email protected] with the subject line "Data Correction."
We investigate every correction report within 48 hours. If we confirm an error, we update the affected content immediately and note the correction at the bottom of the page. For interaction classification errors, we also review all related drug pairs that may be affected by the same data issue.
We maintain a corrections log and publish material corrections (changes to severity classifications or eligibility criteria) in our monthly update notes.