Possible Dilantin toxicity?

[poppy1949]

I developed seizures suddenly at age 42 in 1991. Dx: complex partial seizure due to left temporal lobe injury (car accident in 1966). I didn't stabilize on Dilantin until Diamox was added.  I was perimenopausal at the time.

Last fall I had two gynecological surgeries, including a complete hysterectomy.

1/2009 I was diagnosed as severely Vitamin D deficient (D2 was <4 and D3 was 8) and put on massive dose (50,000 units per week for 8 weeks.

2/2009 I began having spells that felt almost like I was going to faint but I didn't.  My energy just seemed to fall away.  Recent MRI shows normal, recent MRA shows slightly enlarged (2 mm) left artery.  One of these spells happened during a recent EEG.  Immediately as it happened I told the tech this is what I was talking about.  The neurologist said i fell asleep.

1.  Could I have become toxic on generic Dilantin causing these problems?  I am now on a lower dose of name brand.
2.  Could estrogen level or Vitamin D level have affected what happened?
3.  Should I consider changing meds?

[Neuro Forum]

Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.

Without the ability to examine you and obtain a history, I can not tell you what the exact cause of your symptoms is nor can I recommend whether or not you should change your medications. However I will try to provide you with some useful information.

Regarding your sudden episodes of loss of energy (it sounds like sudden episodes of falling asleep basically), this is unlikely to be related to estrogen or vitamin D. Dilantin toxicity could potentially cause sleepiness, but it wouldn't be episodic, it would more likely be more constant, or at least related to your dilantin dose. That is relatively easy to figure out, because all it would require is for blood levels of dilantin to be checked: if the levels are high, in the toxic range, and then your dose is cut down and your episodes stop, then it could be the dilantin. But non-toxic (normal) dilantin levels to my knowledge do not cause sleep attacks.

If you are suffering from sleep attacks, one possibility is a sleep disorder. Sleep apnea, which is due to increased resistance in your airway during sleep, can lead to poor ventilation. It most often occurs in overweight people, but can occur in thinner people with narrow throats or big tongues. A history of snoring is often present. Symptoms during the day include excessive daytime sleepiness, headaches, and other symptoms. This is diagnosed by a study called a polysomnogram. Another sleep disorder that causes sleep attacks in narcolepsy. This is marked by sleep attacks precipitated by emotion or stress. It is also associated with cataplexy, or loss of muscle tone on awakening from sleep. This is also diagnosed with polysomnogram, and a specific test called MSLT.

If your symptoms are a type of faintness or light-headedness, this could be related to a variety of causes. This could include heart problems, anemia, autonomic dysfunction, and others. Since you had an EEG during one and it didn't show seizures, seizures are of course less likely as a cause, but still a possibility, if the seizures are coming from part of the brain too deep to show up on a quick surface EEG.

I recommend follow-up with your neurologist with discussion of your symptoms with him/her, as further testing may be indicated to investigate your symptoms.

Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.

[poppy1949]

Thank you for your guidance.  I ran out of room on my post so I didn't get a chance to say that I had a Dilantin level check in 10/08 that was 19.9 and again 3 weeks ago that was 17.  My normal is around 11-14.  I do have sleep apnea and always use my machine.  If I have narcolepsy in addition, that would be a new condition.

Since my neurologist put me on the name brand and lowered the dosage by 50 mg I am starting to feel better.