Treating seizures with medicines has many aspects and there are many choices to be made. Treatment should stop seizures and have no limiting side effects. When a person starts medication for seizure treatment, approximately two-thirds will find a medication that stops their seizures and without undue side effects. Unfortunately, side effects are a potential problem for medications and we will need to be vigilant for them.
The most common side effects from seizure medications include fatigue, slowed thinking processes, unsteadiness on one's feet, and dizziness. Seizure medications fundamentally work to suppress certain types of brain cell activity. Those types of brain cell activity are often involved in the seizure process but unfortunately some of them are present and necessary in other types of brain function. Those include things constantly being adjusted such as thinking, alertness, our balance, and the movement of our eyes. This is why the medications that we use for epilepsy will frequently have all of these listed as potential side effects. Each medication has side effects unique to that drug and depending on which medication is appropriate, we should discuss those potential side effects and decide which medication is best for the person.
Again, the goal is to choose a medication completely eliminating seizures, produce no limiting side effects, which is easy to take and use, comes in many forms, and is readily available. These are sometimes challenging goals as no ideal medicine exists. An ideal medicine taken daily, has no interactions with other medications, and is easily monitored in the blood stream. Sadly, there is no ideal medication but those are the features of an ideal medication, and the closer we can get to these goals, the better the care will be.
So patients ask "So which medication should I take?"
Well, we have to determine if the patient is experiencing partial seizures or generalized seizures. Partial seizures are the most common seizure, and many of our medications have been tested and shown to be effective in treatment of partial seizures.
Medications are frequently described as older generation medication or part of the newer generation of seizure medications available since the early 1990's. Older generation medications include medications like Dilantin (Phenytoin), Tegretol (Carbamazepine), Phenobarbital, Mysoline (Primidone), and Depakote (Valproic Acid). These medications have been available for decades and have been most commonly used for the treatment of partial seizures. Many physicians have learned to use the medications during their training and they are familiar with their many positive and negative attributes.
Phenobarbital is the oldest of our currently used medications. It has been available since 1912 and has the advantage of being able to be taken once daily and remaining relatively stable in the blood stream. It has the reputation of treating generalized tonic and clonic seizures but being less effective against partial seizures such as simple partial and complex partial seizures. Phenobarbital has well recognized blood testing levels and has not been identified to produce any long-term negative consequences except lowering someone's thinking abilities and decreasing bone density. Phenobarbital's overall success is not as good in the treatment of partial seizures as many other medications and its use has slowly decreased in comparison to other medications. It is available in pill and intravenous form and can frequently be used for short periods of time to eliminate ongoing seizures.
Dilantin (Phenytoin) is a unique medication discovered by a specific program looking for medications that can stop seizures. It was the first of a long list of medications discovered by the National Institute of Health and its program to develop seizure medications. Dilantin may be taken once daily, making it convenient and is effective against partial and tonic-clonic seizures. It is available both as a long-acting capsule, a chewable tablet for children, unstable syrup, and IV form. It has long been used as initial treatment for all types of seizures. Dilantin has many difficulties including an unpredictable change in the level with changes in the amount taken, an interaction with many other medications including commonly used blood thinning agents, aspirin, and birth control pills, a decrease in the bone density which does not respond to more Calcium and Vitamin D, and potential slowed thinking difficulties. Still Dilantin remains the most commonly used medication for seizures due to significant familiarity to physicians.
Tegretol (Carbamazepine) has also been available for decades and is recognized as good treatment for partial seizures. Tegretol comes in several forms including an elixir and sustained release capsules and tablets known as Tegretol XR and Carbatrol. Tegretol must be taken at least twice per day and does interact with many medications including some commonly used antibiotics, birth control pills, and other seizure medications. Tegretol has a pattern of producing excessive fatigue that sometimes does not go away. Tegretol is not effective in generalized seizures such as absence and has been known to make them worse. Occasionally, Tegretol can lower the amount of salt in the blood stream, although this has not been known to cause patients significant problems.
Depakote (valproic acid, divalproex) is the newest of the older generation medications. Depakote is available in several forms including an elixir, immediate release tablet, and several sustained release formulations, and an intravenous form. Potentially the first of a group of medications known for its ability to treat all seizure types, Depakote has become the drug of choice for generalized types of seizures such as absence and generalized tonic and clonic seizures and is effective in partial seizures. This broad spectrum of activity is a principle strength for Depakote. Side effects include stress to the liver, weight gain related to stimulation of the appetite, hair loss related to fragileness of hair fibers, and a tremor of the hands. Special attention regarding Depakote and the reproductive system has been raised concerning Depakote's ability to produce a syndrome known as Polycystic Ovary Syndrome leading to infertility in women. Issues about depression of male sexuality have also been raised with Depakote.
Since our medications had limitations, new medications were developed. The results of this 15 year focus resulted a number of new medications, the new generation antiepileptic drugs. The attempt was to produce medications with fewer side effects and fewer interactions with other medications. The initial treatment, where the greatest successes lie, required minimizing the negative aspects of drug so therapy was more likely to succeed early.
Felbatol (Felbamate) is a drug which lead these new generation medications with its release in the fall of 1993. Felbatol's use is infrequent because two serious, life threatening side effects were identified; fatal Hepatitis and aplastic anemia. Occurring in a small portion of patients who were predominantly adult, these side effects necessitated transplantation of liver and bone marrow and have limited the use of Felbatol. Felbatol's side effects include headache and insomnia and it does interact substantially with other seizure medications including Dilantin, Tegretol, and Phenobarbital. It is taken three times per day.
Neurontin (Gabapentin) is a drug indicated for partial onset seizures and is taken three times per day. It has been shown to be an effective add-on choice to other medications and is easily done so with no drug interactions. Its side effects are relatively few and studies have shown it useful in the elderly compared to Tegretol. Neurontin is not broken down but leaves by the kidney and so kidney function, when it is reduced, requires adjustment of the dose. Neurontin has been found to be useful in other conditions and most of its uses currently are in the area of pain management.
Lamictal (Lamotrigine) was released the year after Neurontin in 1994. It showed effectiveness in partial seizures and studies suggest a broad spectrum of activity for both partial and generalized seizures. Lamictal is taken twice daily and has some interactions, particularly with Depakote. Principle benefits of Lamictal appear to be its low side effect rate. Lamictal's principle difficulty is in the area of rash. When the bloodstream Lamictal concentration increases to quickly, person is prone to having a diffuse body rash. Some of these rashes are allergic, but the majority are not. On a rare occasion these rashes can be life threatening associated with other problems including the liver and bone marrow difficulties. Lamictal has some considerable use outside of the United States and in fact was available over seas for a number of years, and hence has significant numbers of birth exposures without a pattern of significant malformation.
Topamax (Topiramate) is a drug indicated for the treatment of partial seizures, as well as with the treatment of fairly severe epilepsies (Lennox Gastaut). Topamax is taken twice daily and has few interactions with seizure medications. Topamax also shares the quality of Depakote and Lamictal in providing a benefit for multiple types of seizures in both the partial and generalized category. Potentially one of Topamax's largest side effects can be viewed as a positive event. Topamax has the tendency to suppress appetite, which may be a significant benefit. Other side effects of Topamax include a perception of thinking slowing.
Gabitril (Tiagabine) is a medication used for the treatment of partial seizures, so its current use is limited. This is a medication used three times daily that appears to have significant interactions with other medications. In the presence of medications stimulating the liver, such as Dilantin and Tegretol, Gabitril levels are difficult to raise. Sedation and fatigue appear to be Gabitril's most common side effects.
Keppra (levetiracetam) was approved in the year 2000 and shows effectiveness in the treatment of partial seizures. Taken twice daily, Keppra has not been associated with interactions with other medications and its metabolism is relatively limited. Patients find the medication easy to take and Keppra may be increased quickly. It is effective at its recommended starting dose. Keppra's principle side effect detractor is a reported difficulty with behavior disturbance. This behavior disturbance has been seen more frequently in children by report but does not occur very often in any group.
Trileptal (Oxcarbazepine) was released for the treatment of seizures in 2000. It is chemically similar to the drug Tegretol and is taken twice daily. Trileptal has few interactions with other medications. It is indicated for the treatment of partial seizures. Trileptal's principle side effect is fatigue, a lowering of blood salt levels such as is seen with Tegretol is also seen with Trileptal as a relatively rare phenomenon.
Zonegran (Zonisamide) is a drug that was originally released in Japan many years ago and is indicated for the treatment of partial seizures. The Japanese literature suggests that Zonegran may have use in other seizure types including generalized seizures. Zonegran may be taken once or twice daily and is generally well tolerated without significant side effects. There is a potential cross-reaction between individuals who are allergic to Zonegran and Sulfa antibiotics. Zonegran's principle side effect is a potential positive one with reductions in weight occurring in approximately 6% of patients.
Then patients say "Well, that's a lot of choices. Tell me the one I should take."
And I reply we will pick the one you feel the most comfortable with and see how it works.