Generic Substitutions for Brand-Name Drugs

Staff Report

Everyone’s concerned about the rising cost of healthcare.  You probably hear it whenever you prescribe medications for your patients.  Either the patients or their insurance company keep asking for generic drugs instead of brand-name drugs.  The patient’s cost for brand-name drugs can be much higher for those who have insurance, and overall prices are definitely much higher for those who do not have insurance.  You must be cautious before you consent to those requests for generic drugs.  It is not simply a matter of substitution of a cheaper drug for a more expensive one — they are not always 100% identical.

Physicians and patients often ask about the safety and efficiency of generic drugs, when they are substituted for brand-name drugs.  The USFDA generally approves a generic substitute if it has proven to be “identical, or bioequivalent” within a certain percentile to a brand-name drug in dosage form, safety, strength, route of administration, quality, performance characteristics, and intended use.  Pawel Lewek, MD and Przemyslaw Kardas, MD, PhD, in their article on generic drugs in the November 2010 issue of The Journal of Family Practice, recommend that, when in doubt, physicians check the FDA’s Orange Book:  Approved Drug Products with Therapeutic Equivalence Evaluations, online at http://www.accessdata.fda.gov/scripts/cder/ob/default.cfm.

Many articles recommend that physicians monitor some generic drug substitutions closely.  In particular, Drs. Lewek and Kardas feel that the most caution should be taken with antiepileptic (anti-seizure) drugs.  Martin Sipkoff, in his article on generic substitution in Modern Medicine magazine dated March 2010, adds immunosuppressants, psychotropic agents (antidepressants), thyroid drugs, antiarrthythmic drugs, and modified-release formulations to the list that needs careful monitoring once a switch is made to generic drugs.

While brand-name drug manufacturers can update their warning labels on brand name drugs if they uncover new evidence of danger, generic makers don’t have the same authority.  A ruling by the US Supreme Court last year limited lawsuits against generic manufacturers for failing to provide updated warnings.

Drs. Lewek and Kardas performed a literature search and the generic drugs are in general less safe or effective then the equivalent brand drug.  There are strict standards that exist to maintain the quality of the generic equivalents. The doctors looked at 47 studies covering nine subclasses of cardiovascular medications with no evidence that the brand drug performed better than the generic.  Plus the generics cost 30% to 60% less than the brand drug in most cases.  Lower co-pays for the generics also improved patient compliance to remain on medication.

In most cases, there is no “evidence-based” reason to choose the brand drug over the generic.  But when in doubt, check the Orange Book at the above link.