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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 21 of 21. This is the beginning of the thread.
Posted by SLS on August 24, 2005, at 6:26:25
What are some of the pharmacological properties Keppra (levetiracetam) possesses? How is it thought to work to prevent seizures? What else does it do?
Thanks.
- Scott
Posted by Nickengland on August 24, 2005, at 8:54:40
In reply to Keppra pharmacological properties - Shawn T.?, posted by SLS on August 24, 2005, at 6:26:25
Hello Scott,
Funny you mention that, as I was going to post a similar message myself with regards to Topamax..
Although I couldn't find much in-depth information about the Pharmacodynamics of Keppra from Wikipedia, I was able to find this...
The drug is a Pyrrolidine - which is...
Pyrrolidine is a nearly colorless liquid pyrrole to which four hydrogen atoms have been added. It has an ammonialike odor and is the structural basis of the amino acid proline as well as hydroxyproline.
Not sure if this brief description will help..
Levetiracetam (brand name: Keppraź) is an anticonvulsant medication used to treat epilepsy. It is S- enantiomer of etiracetam, structurally similar to the prototypical nootropic drug piracetam (Nootropil). Along with other anticonvulsants like gabapentin (Neurontin), it is also sometimes used to treat neuropathic pain.
Kind regards
Nick
Posted by Shawn. T. on August 24, 2005, at 20:59:07
In reply to Keppra pharmacological properties - Shawn T.?, posted by SLS on August 24, 2005, at 6:26:25
Keppra inhibits N-type calcium channels in a manner that is not related to their activation states (Lukyanetz et al., 2002; http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11879381). These channels have three general states: open, closed, and inactivated. The inactivated state transiently occurs after the open state, and an inactivated channel cannot open even under favorable voltages. Many drugs affect voltage-gated channels in a use-dependent manner, which means that they preferentially bind to the channel pore when it is inactivated. Keppra is not one of these drugs.
Lukyanetz et al. also suggested that only a certain subtype of N-type calcium channels may be affected by Keppra. They based this suggestion on their examination of Keppra's effects on CA1 pyramidal hippocampal neurons. Other researchers have found that kindling, an animal model for seizures, involves an increase in the expression of N-type calcium channels in CA1 and CA3 hippocampal neurons (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10625050). N-type calcium channels affect processes such as neurotransmitter release, synaptic plasticity, and gene expression. As a result, they may involved in the hyperexcitability of neurons and in some types of epilepsy. Keppra has been approved by the FDA for only one use: adjunctive therapy in the treatment of partial onset seizures in adults and children 4 years of age and older with epilepsy.
Shawn
Posted by SLS on August 25, 2005, at 6:50:34
In reply to Re: Keppra pharmacological properties - Shawn T.? » SLS, posted by Shawn. T. on August 24, 2005, at 20:59:07
Hi Shawn.
Thank you so much for coming to my rescue! Levetiracetam is an atypical AED, and I wasn't sure if any mechanisms for its efficacy have been proposed. Of course, there might also be other observed properties that have not been allocated a therapeutic function.
You might like to take a look at this:
http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=15210974
I have spent the last two days muttering expletives because Keppra stopped working for me to treat my bipolar depression. I really wasn't expecting much from this drug, as it has not garnered many supporters for its use in affective disorders. The thing is, I started to respond to it towards the end of last week after being on it for only 10 days. Monday and Tuesday were particularly good days. The antidepressant effect that Keppra produced was broad, of significant magnitude, and unmistakable. This response began to fade by Tuesday night and practically disappeared entirely by last night. This has been my pattern of response to antidepressant psychotropics for over 20 years. I begin to respond robustly during the second week of treatment, and tachyphylaxis occurs within three or four days subsequent. Is a period of 3 days meaningful to you? Can you think of anything going on biologically that occurs in 3 days that might account for my development of tachyphylaxis to these drugs? I occurs with standard antidepressants, anticonvulsants, and atypical neuroleptics.
I had become particularly interested in Keppra after reading the following abstract:
I managed to consult with Dr. Kaufman. It was with great serendipity that he turned out to be the author of this paper. I had no knowledge of this man's work before going in to see him. How weird is that?
Thanks.
- Scott
Posted by Shawn. T. on August 25, 2005, at 15:19:51
In reply to Re: Keppra pharmacological properties - Shawn T.? » SLS, posted by Nickengland on August 24, 2005, at 8:54:40
I've written about Topamax's mechanism of action at http://www.neurotransmitter.net/epilepsy_drug_reference.html ... that might help to answer your question.
Shawn
Posted by Shawn. T. on August 25, 2005, at 15:35:19
In reply to Re: Keppra pharmacological properties - Shawn T.? » Shawn. T., posted by SLS on August 25, 2005, at 6:50:34
Thanks, I wasn't aware of that finding. I wonder if it has anything to do with Keppra's effect on N-type calcium channels. I don't know of any good explanations for your tachyphylaxis.
Shawn
Posted by SLS on August 25, 2005, at 17:32:55
In reply to Re: Keppra pharmacological properties - Shawn T.? » SLS, posted by Shawn. T. on August 25, 2005, at 15:35:19
Hi Shawn.
> I don't know of any good explanations for your tahyphylaxis.
Do you know of any bad ones?
:-)
- Scott
Posted by Nickengland on August 26, 2005, at 6:53:14
In reply to Re: Keppra pharmacological properties - Shawn T.? » Nickengland, posted by Shawn. T. on August 25, 2005, at 15:19:51
Hi Shawn,
Thanks for providing that information..
This post maybe better suited on the alternative board, but it is about the drug Topamax ~ what i'm curious to know, is through the pharmacological mechanisms of the drug...I wonder what nutrients it could possibly be putting a strain on ones body chemistry. I'm not feeling any really bad unwanted side effects, but because i'll be taking this drug longterm I'm trying to figure out what, if any of the best vitamins could be for me to take which the topamax could be draining from my body - so I can basically achieve good all round health..
Do you have any ideas?
Kind regards
Nick
Posted by ed_uk on August 26, 2005, at 14:02:46
In reply to Re: Keppra pharmacological properties - Shawn T.? » Shawn. T., posted by Nickengland on August 26, 2005, at 6:53:14
Hi Nick,
Topamax increases the excretion of potassium, sodium and bicarbonate by the kidneys - this is because it inhibits an enzyme called carbonic anhydrase.
At normal doses, the sodium loss it not a problem. Most people eat too much salt anyway.
Potassium and bicarbonate levels can be measured by a blood test. Effervescent potassium bicarbonate tablets are available on presceription in the UK. Since you're on such a low dose of Topamax, it's very unlikely that you'd need to take them.
Kind regards
~ed
Posted by Nickengland on August 27, 2005, at 16:39:50
In reply to Re: Keppra pharmacological properties - Shawn T.? » Nickengland, posted by ed_uk on August 26, 2005, at 14:02:46
Hi Ed,
Thanks for posting that :-)
>Topamax increases the excretion of potassium
Due to the excretion of potassium, how about taking a potassium supplement?
Kind regards
Nick
Ps this is tricky as I am talking supplements but then we are talking about the function of Topamax, hence a re-direct :-O lol
Posted by ed_uk on August 28, 2005, at 8:03:15
In reply to Re: Keppra pharmacological properties - Shawn T.? » ed_uk, posted by Nickengland on August 27, 2005, at 16:39:50
Hi Nick!
>this is tricky as I am talking supplements but then we are talking about the function of Topamax, hence a re-direct :-O lol
But we're talking about Topamax :-)
>Due to the excretion of potassium, how about taking a potassium supplement?
I don't think you'll need one - since you're on such a low dose. OTC supplements contain very low doses of potassium - inadequate to treat a deficiency. High doses of potassium can only be given under medical supervision.
Kind regards
~Ed
Posted by Shawn. T. on August 28, 2005, at 11:25:57
In reply to Re: Keppra pharmacological properties - Shawn T.? » Shawn. T., posted by SLS on August 25, 2005, at 17:32:55
>Do you know of any bad ones?
I tried looking through the literature, but I couldn't find any useful information.
Shawn
Posted by SLS on August 28, 2005, at 13:28:55
In reply to Re: Keppra pharmacological properties - Shawn T.? » SLS, posted by Shawn. T. on August 28, 2005, at 11:25:57
> >Do you know of any bad ones?
>
> I tried looking through the literature, but I couldn't find any useful information.
>
> Shawn
Thanks for trying, Shawn. I really appreciate it.I was thinking that Keppra might affect terminal vesicles in a way similar to reserpine at first via SV2a receptors. This might account for the rapid antimanic effect sometimes seen with Keppra. Afterwards, the function of the vesicles might become reregulated in a manner similar to cell membranes in response to exposure to antidepressants. Perhaps this modulation would involve synergistic contributions by the modulation of N-type calcium channels that are required for vesicular release.
Just thinking out loud...
I wish this Keppra would give me some more hope to cling to. So far, I have not experienced a return of the antidepressant response I gleaned during the first week. I am not feeling worse, though. What I find significant, however, is that I went through a day of severe worsening of my condition after the initial improvement disappeared from which I recovered quickly. Again, I wonder if this wasn't a reserpine-like action of Keppra that caused a brief period of monoamine depletion before reregulation began to take place.
- Scott
Posted by Nickengland on August 29, 2005, at 12:05:32
In reply to Re: Keppra pharmacological properties - Shawn T.? » Nickengland, posted by ed_uk on August 28, 2005, at 8:03:15
Hi Ed!
>But we're talking about Topamax :-)
Indeed, I do believe we are :-)
>I don't think you'll need one - since you're on such a low dose. OTC supplements contain very low doses of potassium - inadequate to treat a deficiency. High doses of potassium can only be given under medical supervision.
Hopefully I would'nt want to add any further presciption medicines to what i'm already taking right now I think....the OTC supplements of potassium at holland and barrett are only 99mg when I looked online ~ I bet this is really low compared to prescription strength?
One thing I found of interest though about the potassium supplement in general (I was reading my book, the Vitamin Bible ~ you can probably guess its biased and covers quite abit about supplements lol) Under Potassium, one of the things it states "What it can do for you" is.....
Aid in clear thinking by sending oxygen to the brain.
Although I don't have too much of a problem with the cogitive effects, taking 2 anticonvulsants, at times I do feel abit cloudy in my thinking.
I wonder, would it do any harm to take a supplement along side the medication i'm taking now do you think?
To be honest as well, the natural sources of potassium that I could/should be consuming in my diet I appear to be lacking in too ~ do you think it makes sense to give it try?
Kind regards
Nick
Ps I think next time I see my psychiatrist, I doubt he'll request, I will ask for a blood test just to check things to make sure everything is okay with reagrds to the Topamax.
Posted by ed_uk on August 29, 2005, at 13:25:54
In reply to Re: Keppra pharmacological properties - Shawn T.? » ed_uk, posted by Nickengland on August 29, 2005, at 12:05:32
Hi Nick!
>I wonder, would it do any harm to take a supplement along side the medication i'm taking now do you think?
I wouldn't recommend it. OTC supplements contain potassium chloride - you don't want that. You want potassium bicarbonate.
>To be honest as well, the natural sources of potassium that I could/should be consuming in my diet I appear to be lacking in too ~ do you think it makes sense to give it try?
I'm told that bananas are high in potassium.
>I think next time I see my psychiatrist, I doubt he'll request, I will ask for a blood test just to check things to make sure everything is okay with reagrds to the Topamax.
You need a 'U&Es' test (urea and electrolytes) - including urea, sodium, potassium, chloride, creatinine and bicarbonate. Most importantly, the test should measure your bicarbonate level.
I believe the U&Es test is called a 'chem 7' in the US, but a 'chem 7' includes glucose as well.
Kind regards
~Ed
Posted by ed_uk on August 29, 2005, at 13:31:36
In reply to Re: Keppra pharmacological properties - Shawn T.? » ed_uk, posted by Nickengland on August 29, 2005, at 12:05:32
PS. Correction of metabolic acidosis due to Topamax may require a combination of sodium bicarbonate and potassium bicarbonate. I think it's very unlikely that you'll need either though, since you're on such a low dose. Pronounced metabolic acidosis is more likely to be a problem for people on very high doses.
~Ed
Posted by Nickengland on August 29, 2005, at 16:03:05
In reply to Re: Keppra pharmacological properties - Shawn T.? » Nickengland, posted by ed_uk on August 29, 2005, at 13:25:54
Hi Ed!
>I wouldn't recommend it. OTC supplements contain potassium chloride - you don't want that. You want potassium bicarbonate.
I see, its the bicarbonate thats important? What is bicarbonate?
LOL - Would I be right in thinking potassium gluconate would be of no use either?
>I'm told that bananas are high in potassium.
I do enjoy bananas, I think i'll start eating them more often :-)
>You need a 'U&Es' test (urea and electrolytes) - including urea, sodium, potassium, chloride, creatinine and bicarbonate. Most importantly, the test should measure your bicarbonate level.
On the blood test sheet you get from the GP (you know the standard form) on the part where the doctor fills in additonal notes ~ would he just put "Topamax" here.
Or have to write: sodium, potassium, chloride, creatinine and bicarbonate ~ Or are all those included because he checked the box for a 'U&Es' test?
Many thanks for helping me with these questions Ed!
Kind regards
Nick
Posted by Nickengland on August 29, 2005, at 16:12:09
In reply to Re: Keppra pharmacological properties - Shawn T.? » Nickengland, posted by ed_uk on August 29, 2005, at 13:31:36
Hi Ed!
>PS. Correction of metabolic acidosis due to Topamax may require a combination of sodium bicarbonate and potassium bicarbonate. I think it's very unlikely that you'll need either though, since you're on such a low dose. Pronounced metabolic acidosis is more likely to be a problem for people on very high doses.
Very true. Its great having the knowledge to know about these side effects in more detail and more importantly how to treat them if they were to occur.
Hypothetically speaking, if one was to get metabolic acidosis, would it be standard practice to take sodium bicarbonate and potassium bicarbonate to correct the imbalance ~ and therefore you can continue treatment with topiramate?
Kind regards
Nick
Posted by ed_uk on August 29, 2005, at 16:19:25
In reply to Re: Keppra pharmacological properties - Shawn T.? » ed_uk, posted by Nickengland on August 29, 2005, at 16:03:05
Hi Nick,
>What is bicarbonate?
It's an ion, important in maintaining the body's acid-base balance.
>Would I be right in thinking potassium gluconate would be of no use either?
Yes :-(
>On the blood test sheet you get from the GP (you know the standard form) on the part where the doctor fills in additonal notes ~ would he just put "Topamax" here.
Yes, he'd probably just write that you take topiramate and tick the U&E box.
Kind regards
Ed
Posted by ed_uk on August 29, 2005, at 16:20:16
In reply to Re: Keppra pharmacological properties - Shawn T.? » ed_uk, posted by Nickengland on August 29, 2005, at 16:12:09
>Hypothetically speaking, if one was to get metabolic acidosis, would it be standard practice to take sodium bicarbonate and potassium bicarbonate to correct the imbalance ~ and therefore you can continue treatment with topiramate?
It might be more common to discontinue Topamax.
~Ed
Posted by Nickengland on August 30, 2005, at 13:44:20
In reply to Re: Keppra pharmacological properties - Shawn T.? » Nickengland, posted by ed_uk on August 29, 2005, at 16:19:25
Hi Ed,
>Yes, he'd probably just write that you take topiramate and tick the U&E box.
I sometimes get paranoid that my GP is not checking what he should lol
Thanks for your help Ed :-)
Kind regards
Nick
This is the end of the thread.
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