Medication Guides
According to the U.S. Food and Drug Administration and CMS NADAC files compiled on methodology, these pages map recall classes, FAERS volume, and generic-price gaps onto the 682-drug catalogue (Enforcement Reports as of 2026-06-25).
Count versus seriousness
Class II is #1 of 3 FDA recall classes by action count (997 of 1,179, 85%) while Class I is the seriousness board (103, 9%). Class III, not Class I, is the smallest group.
- #1
- Class II by count
- 103
- Class I actions
- 79
- Class III (fewest)
- 682
- drugs in the catalogue
Registry voice: class is the FDA risk grade for named lots, not advice about stopping a medicine.
Percent gap versus brand unit price
Naltrexone is NADAC gap largest of 5 at 99.9% (#1 of 147) at brand-unit #2 ≠ Teriparatide brand-unit #1 of 147 at $1,726.47 (gap #135 at 51.8%).
- 99.9%
- Naltrexone gap
- $1,726.47
- Teriparatide brand unit
- 147
- paired NADAC rows
- 85.1%
- mean gap
According to CMS NADAC compiled on /methodology. A high percent gap is not the same map as a high brand unit price.
Guide hub by family
Exclusive split of the 7 guide cards on this hub by editorial tag. Catalog inventory, not a treatment map.
Catalogue Rx vs OTC flag
Exclusive cut of the 682-drug catalogue by the openFDA OTC flag. Orthogonal to recall-class and NADAC duals above.
Labeled pair severity mix
Exclusive cut of 3,919 FDA-labeled drug-drug pairs by label severity. Registry grades, not per-patient risk.
What These Guides Cover
PlainMeds publishes 7 registry guides against the same 682-drug catalogue that powers per-medication profiles, so a recall-class definition maps to actual FDA enforcement records and a CYP claim maps to labeled interaction rows.
The guides are intentionally narrow rather than encyclopedic: they cover the questions our search analytics surface most often (labeled pair volume, generic NADAC gaps, recall class counts) and the topics where official FDA documentation is dense. Each guide names its primary FDA/CMS data source, links to the relevant detail-page records, and documents what the source cannot tell us: passive reporting limits in FAERS, manufacturing-quality vs efficacy distinctions in recalls, and NADAC unit prices that are not retail quotes.
Understanding Drug Interactions
FDA-labeled interaction types and severity counts from Structured Product Labels.
Generic vs Brand Name Drugs
FDA bioequivalence plus live CMS NADAC: the largest percent gap is not the highest brand unit price.
Pain Relievers Compared
FAERS report volume for acetaminophen, ibuprofen, naproxen, and aspirin, not a which-to-take verdict.
How Drug Interactions Work
Pharmacokinetic vs pharmacodynamic mechanisms, CYP450 enzymes, enzyme inhibitors and inducers, food-drug interactions, and the FDA severity classification system.
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow-therapeutic-index medicines; no individual dosing, monitoring, or substitution direction.
How to Read an FDA Drug Label
A source-record map of Structured Product Label sections: indications, warnings, contraindications, adverse reactions, and Boxed Warnings.
FDA Drug Recalls Explained
FDA recall classes I-III from Enforcement Reports: Class II leads by count; Class I is the seriousness board, not the rarest class.
Methodology
Every guide on PlainMeds is derived from three public FDA/CMS datasets: FDA Structured Product Labels (SPL/DailyMed), FDA Adverse Event Reporting System (FAERS), and CMS National Average Drug Acquisition Cost (NADAC).
Factual content, warnings, dosages, contraindications, interaction severity, adverse event counts, acquisition costs, is taken directly from official FDA/CMS databases without modification. editorial plain-language simplification is applied only to produce plain-language summaries alongside the original labeling.
See the full methodology & limitations page for processing pipeline details, FAERS interpretation caveats, data vintage, and accuracy commitments.