unexplained drop in dilantin level

loveslight57 · 08-30-2007, 05:17 PM

I have been taking dilantin since 1991, 500 mg a day is the effective dose for me. The only problems occurred after a lowering of dose by my docter.
Recently I had a seizure taking the 500 mg a day. My dilantin level 10. This was about 3 to four hours after my morning dose.
My historical levels and therapeutic range has been 16 to 21(trough). I have maintained good control and levels for many years on this dose. This led me to suspect the dilantin batch that I was taking at the time. After switching lots, my levels are fine again within one week and have I had levels tested every week since 15.9, 19,20.,21.9,22.. Is this a coincidence, or is it the dilantin. Three weeks before the seizure, I had a riding accident and hurt my back, causing swelling and much pain, I took advil for it, but do so every month reqularly for menstrual pain. I can see this being the cause of the seizure, but not the lowered level. Anyone else have this problem recently
I sent the pills for testing to Pfizer and called the fda. the pills were dated
4/17/07 and were from Medco. thanks

neurowreck · 08-30-2007, 08:44 PM

Dilantin used to be made by a differnt company...are these generic? That can be a big cause for a lowered level. Ten is still at the lower end of normal limits. I wouldn't worry too much unless it continues to be low. Have you been more active than usual? Metabolism changes? Diet pills? I'd be more concerned about levels over 20, in the toxic range.

loveslight57 · 08-31-2007, 09:28 AM

Quote:

Originally Posted by neurowreck

Dilantin used to be made by a differnt company...are these generic? That can be a big cause for a lowered level. Ten is still at the lower end of normal limits. I wouldn't worry too much unless it continues to be low. Have you been more active than usual? Metabolism changes? Diet pills? I'd be more concerned about levels over 20, in the toxic range.

The dilantin was Parke Davis distributed by Medco. I need to stay in the upper therapeutic range of 16 to 20. And have done so for many years. I had a gran mal on the level of 10. After switching lot nos. of the dilantin, my levels have been 15.9, 19, 20, 21. , 22 tested weekly.
My habits, exercise, etc remained the same, However, I did have a riding accident 3 weeks prior and hurt my back causing swelling. I can see this as a reason for the seizure but the doctors said it would lower the level. I did take motrin. But I have taken motrin for many years too.

neurowreck · 08-31-2007, 08:18 PM

The riding accident could cause generalized stress, but the back swelling shouldn't cause med levels to change. You're bound to get different lot numbers since they can only make so many of a certain lot. But, the quality control should still guarantee that there are the same number of mg/pill no matter what the lot. I don't think the Motrin would cause a lower dilantin level. Did you have the test about the same time after taking the meds as previous tests? Granted, the half-life and overall level should stay relatively stable, but there can be some changes, depending on when you took the med and when you got the level done....

loveslight57 · 09-02-2007, 02:30 PM

Quote:

Originally Posted by neurowreck

The riding accident could cause generalized stress, but the back swelling shouldn't cause med levels to change. You're bound to get different lot numbers since they can only make so many of a certain lot. But, the quality control should still guarantee that there are the same number of mg/pill no matter what the lot. I don't think the Motrin would cause a lower dilantin level. Did you have the test about the same time after taking the meds as previous tests? Granted, the half-life and overall level should stay relatively stable, but there can be some changes, depending on when you took the med and when you got the level done....

The low level of 10 was taken about 3 hours after my morning dose.
All other levels were trough levels taken before I took the morning dilantin. All at the same relative time. My surprise is that a level taken after my dose could be so low compared to ones prior to my dose. I realize that the lot nos. change and I am skeptical of the qc of this lot. dated 4/17/07 from Medco.