Side effects of anti-epilepsy drugs

[Digitalis]

I've been taking Tegretrol (an anti-epilepsy medication) for over 10 years. I recently found out that Tegretol and related drugs frequently cause problems with reproductive hormones.

I've always thought that I had low libido- but recently it has bottomed out. I'm 24 years old and otherwise healthy, so obviously this is abnormal. I also seem to have many of the symptoms of hypogonadism, in particular adrenal fatigue that marianco has discussed.

Here is a pub med abstract that may be of interest:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16217052&query_hl=1&itool=pubmed_docsum

I plan to discuss this with my doctor soon and would appreciate any advice.

Thanks.

edit: Tegretol is brand name of carbamazepine.

 

[marianco]

Anticonvulsant medications and Testosterone

Certain substances, particularly some anticonvulsant medications, are known as "enzyme inducers". Such substances speed up certain liver enzymes which break down medications and other substances, including hormones. Examples include Carbamazine (Tegretol), Topiramate (Topamax), Oxcarbazepine (Trileptal), Phenytoin (Dilantin), Phenobarbital (a barbiturate), and Lamotrigine (Lamictal - albeit for most people weakly). These induce the liver to get ride of some reproductive hormones faster. Women on birth control pills, particularly, have to be aware of the interaction since an unplanned pregnancy may be the result.

Not all anticonvulsant medications have such an interaction. Valproic Acid (Depakote), for example, is known as an "enzyme inhibitor" - it slows down the break down of some substances or medications. Gabapentin (Neurontin) has no such liver interaction. Zonisamide (Zonegran) is another example. The liver induction also varies from person to person. For example, in the cited medline abstract, Lamictal did not show a reduction in testosterone for the men tested. However, since it does induce liver enzymes mildly, such as result may vary depending on the particular person. Off the top of my head, Pregabalin (Lyrica) may also be an anticonvulsant that does not induce liver enzymes (though I would have to check the PDR to check on this).

Anticonvulsant medications do reduce cognitive functioning as they work to reduce brain activity known as seizures. They reduce a person's I.Q. a bit, depending on the dose. This may itself reduce libido, change mood, etc.

 

[SWALE]

I am glad you are here, marianco. I, too, am learning from you.

 

[Digitalis]

Certain substances, particularly some anticonvulsant medications, are known as "enzyme inducers". Such substances speed up certain liver enzymes which break down medications and other substances, including hormones. Examples include Carbamazine (Tegretol), Topiramate (Topamax), Oxcarbazepine (Trileptal), Phenytoin (Dilantin), Phenobarbital (a barbiturate), and Lamotrigine (Lamictal - albeit for most people weakly). These induce the liver to get ride of some reproductive hormones faster. Women on birth control pills, particularly, have to be aware of the interaction since an unplanned pregnancy may be the result.

Not all anticonvulsant medications have such an interaction. Valproic Acid (Depakote), for example, is known as an "enzyme inhibitor" - it slows down the break down of some substances or medications. Gabapentin (Neurontin) has no such liver interaction. Zonisamide (Zonegran) is another example. The liver induction also varies from person to person. For example, in the cited medline abstract, Lamictal did not show a reduction in testosterone for the men tested. However, since it does induce liver enzymes mildly, such as result may vary depending on the particular person. Off the top of my head, Pregabalin (Lyrica) may also be an anticonvulsant that does not induce liver enzymes (though I would have to check the PDR to check on this).

Anticonvulsant medications do reduce cognitive functioning as they work to reduce brain activity known as seizures. They reduce a person's I.Q. a bit, depending on the dose. This may itself reduce libido, change mood, etc.

Thanks, marianco.

From what I've read Trileptal doesn't induce these enzymes as much as Tegretol. I'll ask my doctor about switching.

Here is a table from a study which shows the levels of hormones in patients taking AEDs compared to control: http://intl.neurology.org/cgi/content/full/56/1/31/TBL3. Total T is higher in patients taking many of the AEDs, but SHBG and estradiol are also increased. Carbamazepine seems to be one of the worst offenders. This study also states that "Replacement of CBZ by OXC resulted in a restoration of normal circulating levels of SHBG and DHEAS contemporaneously with a decrease in the induction of the hepatic P450 enzyme system."

TRT and aromatase inhibitors (testolactone/letrizole) are listed as possible treatments on this page (http://professionals.epilepsy.com/page/hormones_antiepmen.html). I plan to ask my doctor for some lab work to see if TRT is needed.

 

[stat1951]

Certain substances, particularly some anticonvulsant medications, are known as "enzyme inducers". Such substances speed up certain liver enzymes which break down medications and other substances, including hormones. Examples include Carbamazine (Tegretol), Topiramate (Topamax), Oxcarbazepine (Trileptal), Phenytoin (Dilantin), Phenobarbital (a barbiturate), and Lamotrigine (Lamictal - albeit for most people weakly). These induce the liver to get ride of some reproductive hormones faster. Women on birth control pills, particularly, have to be aware of the interaction since an unplanned pregnancy may be the result.

Not all anticonvulsant medications have such an interaction. Valproic Acid (Depakote), for example, is known as an "enzyme inhibitor" - it slows down the break down of some substances or medications. Gabapentin (Neurontin) has no such liver interaction. Zonisamide (Zonegran) is another example. The liver induction also varies from person to person. For example, in the cited medline abstract, Lamictal did not show a reduction in testosterone for the men tested. However, since it does induce liver enzymes mildly, such as result may vary depending on the particular person. Off the top of my head, Pregabalin (Lyrica) may also be an anticonvulsant that does not induce liver enzymes (though I would have to check the PDR to check on this).

Anticonvulsant medications do reduce cognitive functioning as they work to reduce brain activity known as seizures. They reduce a person's I.Q. a bit, depending on the dose. This may itself reduce libido, change mood, etc.

Would greatly appreciate if you could advise where Lyrica stands in this topic. My PCP switched me from Gabapentin (300 mg three times daily) to Lyrica (50 mg three times daily), and this was one of the particulars that I was wondering about. I am already on Xanax XR - which I believe to be an "enzyme inhibitor" and wondered where Lyrica fell into which category. As you know, Lyrica has been in Europe and some other overseas markets for a couple years and was iniitially approved by the FDA (I believe) in December of 2004, but was only released to US market a couple months ago... so finding specific information on it (beyond what is in the little brochure than comes with the prescription) is still kind of tough.

Thanks for any info!


Larry

P.S. Speaking of Dilantin (as I was on it for a month-long trial basis also), I was aware of it being a pretty significant "enzyme inducer" and was specifically aware of the clinical study quoted earlier:

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16217052&query_hl=1&itool=pubmed_docsum

I specifically noted these sections from the study:

...bioactive testosterone levels, bioactive testosterone/bioactive estradiol, and bioactive testosterone/luteinizing hormone were significantly greater in the control and LTG groups than in the CBZ and PHT groups. Sex hormone binding globulin was significantly higher in the CBZ and PHT groups than in all other groups.... Bioactive testosterone was below the control range in 28.2%, including 48% on CBZ, 28% on PHT (Dilantin)...

To me, those were some pretty significant numbers and reactions. Yet when I checked drug interactions at DrugDigest:

http://www.drugdigest.org/DD/Interaction/ChooseDrugs

It would show strong interaction between Dilantin and any of the administered estrogens (example):

http://www.drugdigest.org/DD/Intera...ical+Gel"+"Estrasorb"+"Estratest"+"EstroGel"+

And yet no such interaction was represented when checking Dilantin against the various Testosterone preparations (example):

http://www.drugdigest.org/DD/Intera...terone+Injection"+"Testosterone+Transdermal"+

Is it possible that the Dilantin doesn't have that affect on external administered testosterone? Or is this simply an interaction that they (DrugDigest) has missed? The NIH reported study seems pretty clear-cut....

Again, thanks.

 

[jasonshadow]

For what it's worth, I suffered with Epilipsy since the age of 10years old. I have taken Carbamazine (Tegretol), Topiramate (Topamax), Oxcarbazepine (Trileptal), Phenytoin (Dilantin), Phenobarbital for many years. Then I started to take Paxil. After a few years of taking Paxil I noticed I wasn't having seizures when I forgot one of my pills so I slowly got off all anti-epilipsy drugs. I firmly belive Paxil changed something in my brain to help with the seizures. About 1 years later I started taking Propecia. I am now off both Paxil and Propecia but taking Test. Cyp, HCG, and Armour Thyroid to combat hypogonadism symptoms. I'm not sure if this means anything to you, but just thought I would mention it.