II. Medications: Generic Medications bioequivalent to brand-name drugs
- Warfarin (Coumadin)
- Levothyroxine (Synthroid)
- Cyclosporine (Sandimmune)
- Phenytoin (Dilantin): extended release forms only
- Digoxin (Lanoxin)
- Carbamazepine (Tegretol)
III. Safety
- Generic Drugs have similar efficacy and safety to trade name drugs despite lower cost and different manufacturers
- Concerns about specific Medication Safety may be submitted to local pharmacist or to FDA
- Most Generic Drugs are produced by manufacturers other than the brand/trade product
- "Authorized Generics" are identical to brand/trade name and produced by the same manufacturer
- Packaging and medication appearance often differs from the trade product
- Historically U.S. Generic Drugs have been held to a high standard of equivalence and safety
- However, FDA staffing cuts since 2024 has resulted in a back-log of testing and inspections
- Dietrich (2025) Arch Toxicol 99(6):2239-41 +PMID: 40360856 [PubMed]
- Most bioequivalent Generic Medications may be substituted for one another without significant adverse effects
- Generic Drug absorption is allowed to differ up to 20-25% from trade name product
- Small differences in absorption of different Generic Medications have low clinical impact for most drugs
- However, Exercise caution with narrow Therapeutic Index medications (Immunosuppressants, Antiepileptics)
- References
- (2026) Presc Lett 33(9): 6
IV. References
- Dong (1997) JAMA 277:1205 [PubMed]
- First (1998) Clin Transplant 12:518 [PubMed]
- Handler (1998) Prev Cardiol 1:13 [PubMed]
- Neutel (1998) Cardiovasc Rev Rep 19:49 [PubMed]
- Schroeder (1998) J Clin Pharmacol 38:807 [PubMed]
- Yacobi (1999) Clin Pharmacol Ther 65:389 [PubMed]
- (1999) Med Lett Drugs Ther 41:47-8 [PubMed]
V. Resources
- FDA bioequivalence testing