I do not think I am absorbing my anti-epilepsy medication very well. I know - surprise, surprise.
I take two medications -
- Topamax 200 mgs
- Levetiracetam 2000 mgs
- Both in divided doses
My blood test results - suck -
My medication dosages are higher than the "therapeutic levels" suggested above - and my blood lab results don't seem to fit.
While my grand mal seizures are controlled (thank you Keppra?) I am having multiple complex partial seizures in clusters each week. My family says they are increased, I can't tell the difference because they happen regardless of my awareness level.
(Side note: I am also still pushing along toward brain surgery for the removal of the area of the brain that is the trigger area for the seizures, however the neuro team has suggested that it's a very large section - larger than anticipated in earlier scans - and less likely to be a cure... I still have testing to visualize and narrow it down... another post.)
- My point in posting my medication blood levels was that maybe someone out there has knowledge of this -- epilepsy AND gastric bypass AND medication levels or alternative dosing?
While I am aware that is NORMAL to have absorption issues post gastric bypass - I guess this is some proof - that medication just DOESN'T always work entirely.
The Roux-en-Y gastric bypass is most commonly performed in the United States and produces a more profound and sustained weight loss than the other two methods.2,5 This procedure uses a combined restrictive and malabsorptive approach to induce weight loss. During this procedure, a 30- to 60-mL portion of the stomach is sectioned off in an effort to limit food intake. The small intestine is then cut from the base of the stomach, and the lower intestine is connected to the pouch at the top of the stomach. The narrow opening to the small intestine slows the emptying of the stomach and produces a sensation of early satiety.6 By circumventing the lower portion of the stomach (90% to 95%) and much of the small intestine (the entire duodenum and part of the proximal jejunum), the surface area for absorption is greatly decreased and malabsorption can occur.2
Drug absorption and bariatric surgery
The mechanism of altered drug absorption depends partly on the type of procedure done-restrictive or malabsorptive. In general, drug absorption is affected by drug disintegration and solubility and the surface area available for absorption, all of which can be affected by restrictive procedures. 5,7 Disintegration of the dosage form is the first step needed for drug absorption. The smaller volume of the stomach with restrictive procedures may prevent adequate tablet or capsule disintegration due to reduced gastric mixing.7 Solubility of a drug is dependent on pH. Drugs that are more soluble at a lower pH are absorbed in the stomach, while those that are soluble in more basic environments are absorbed in the small intestine. Changes in the stomach volume after bariatric surgery result in a decrease in gastric acid production and a higher pH compared with the stomach as a whole. The change in pH may cause a decrease in the absorption of medications that rely on an acidic pH for solubility or absorption. A reduction in the surface area of the stomach may further decrease drug bioavailability. These changes may be especially important for drugs that are slowly absorbed, such as sustained-release formulations. Use of liquid formulations or chewing or crushing solid dosage forms (if appropriate) may help overcome some of these factors.
Malabsorptive procedures bypass much of the small intestine.7 This technique not only decreases intestinal length but also limits mucosal exposure of drugs and alters intestinal transit time. Mixing of highly lipid soluble drugs with bile acids may be reduced, with a loss of enterohepatic recirculation and decreased absorption.
In addition to drug absorption, drug distribution can also be affected following bariatric surgery.8 Obesity-related factors that can influence drug distribution include increased blood volume, cardiac output, lean body mass, organ size, and adipose mass. After bariatric surgery, these factors are expected to change and, therefore, may necessitate drug dosing adjustments.