Very few people know that I have a seizure disorder, and probably even fewer understand what that means.
For most of my life, I didn't. I would unexpectedly feel "outside my body," almost as if I were an observer, before losing consciousness. When I awoke, I'd feel confused, sometimes momentarily and other times for much longer. One time, I didn't remember who I was. Another time, I was told I was in Wyoming. I didn't remember how I'd gotten there. When I was younger, my confusion was sometimes mistaken for alcohol or drug abuse.
All of this ended in a Baltimore, Maryland, restaurant when I was 40. A stranger said, "I think you just had a seizure." I denied it at first but eventually sought the care of a neurologist, who prescribed a medication that brought these episodes under control.
I went nearly 20 years without a seizure. Then a series of events put me at risk once again.
My primary care physician was out sick when I went for my annual exam; because I'd been medically stable for so long, her substitute suggested I forego my annual visit to the neurologist. She ordered my medication—normally prescribed by my neurologist—and necessary laboratory tests. The neurology visit wasn't covered in full by my health insurance, so this saved me quite a bit of money. Then the prescription drug provider nudged me to use its mail order option: one copay for Tegretol now covered a three-month supply, saving me $320 a year. A few months later, they refilled my prescription with carbamazepine, the generic version of my medication, because the primary care provider didn't specify that only the brand-name drug be used. They hadn't notified me explicitly of this change, which saved me $60 annually.
Then I visited a friend in Reno, Nevada. After a long day of travel and little sleep, we awoke early the next day and hiked around Lake Tahoe, altitude 6,200 ft. I began gasping almost as soon as we hit the steep trail. I have asthma but figured I'd quickly acclimate.
In the restaurant after our all-day hike, I had that familiar out-of-body feeling. Ten minutes later, I awoke on the floor.
When I saw my neurologist the following week, he noted that sleep deprivation and hypoxia had put me at risk for the breakthrough seizure, but he believed—based on his other patients' experiences—that the most significant factor had been switching to a generic medication.
According to the U.S. Food and Drug Administration (FDA), a generic drug must be "identical" to a brand-name drug "in dosage form, safety, strength, route of administration, quality, performance characteristics and intended use" (see http://bit.ly/4iDTMI). However, generic medications are allowed to produce no less than 80% nor more than 125% of the desired concentration in the bloodstream (see http://bit.ly/y83kp)—a small but potentially significant difference.
Antiseizure drugs, for example, have a very narrow therapeutic range. They, along with some other types of medications, are termed "critical dose drugs." Their use requires blood-level monitoring and their dosing is based on the patient's weight. If a generic version of my medication can potentially cause up to a 20% weaker bloodstream concentration, then it may not be as effective at preventing seizures. Last April the FDA's Pharmaceutical Science and Clinical Pharmacology Advisory Committee acknowledged this possibility, voting to consider stricter bioequivalence standards for critical dose drugs.
My neurologist says he sees two to three breakthrough seizures a year after patients have switched from a brand-name antiseizure drug to the generic equivalent, which is why he won't prescribe generic drugs. When he asked if I could afford Tegretol, I said I couldn't not afford it if I wanted to continue to live seizure- and worry-free.
I've learned my lesson: never assume that saving money is the best choice, get enough rest, drink plenty of fluids, and, if possible, opt for the gentle hike at sea level.