A “generic” is a drug that is broadly equivalent to a brand name medication, but marketed under its chemical name, without advertising, usually at a significantly lower cost.
In most cases, generic products are available once the patent protections afforded to the original developer have expired, and when this happens free market competition leads to substantially lower prices for both the original brand name product and the generic forms.
Insurance companies and pharmacies will try to contain their own costs by encouraging patients to switch to generic medications with lower co-pays or co-insurance.
A generic drug must contain the same active ingredients as the original formulation. According to the FDA, generic drugs are identical or within an 80-125% bioequivalent range to the brand name counterpart.
Generic substitution is not usually a major problem for most medication prescribed for common medical conditions like high blood pressure or diabetes.
Generic substitution for epilepsy medications is more contentious.
The problem is that most pharmacies get generic medications from wholesalers, and a patient on generic medication could potentially get drug from a different manufacturer every month.
Think of going shopping for peanut butter at a wholesale store like Costcos. One month they might have Smuckers brand, the next month Kirkland brand, and then the next month some other brand – they have whatever they could order cheapest that month. While these products all contain peanut butter, they each have slightly different recipes and taste a little bit different.
If you are taking levitiracetam (the generic equivalent of Keppra) for epilepsy, and you switch drug manufacturers every month, you could potentially go from a product that was 125% Keppra bioavailability to a product that was 80% Keppra bioavailability, i.e. a 45% drop in effective drug ingredient at the same “dose”, and this could provoke a breakthrough seizure, with all of the ramifications for safety and driving that would go along with that.
That’s the reason that most neurologists and the Epilepsy Foundation have suggested that well-controlled epilepsy patients stick with brand name medications, so that they know they are getting the same thing every month when they refill their prescriptions.
Thankfully, we are beginning to see new mail order pharmacies, like Nuro Pharma, that will guarantee that the patient receive their generic epilepsy medications from the same manufacturer every month – if you know you are going to get Kirkland every month, it’s probably OK to pass on the Smuckers!!