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Thread: 4ap aminopyridine

  1. #1
    Junior Member
    Join Date
    Jul 2001

    4ap aminopyridine

    >Please can you simple tell me how it works, and please tell me how
    >long the human trials will go on before this drug will be available
    >to the public. And also can you tell me how long you would have to
    >take the drug, also if possible can you please tell me how much it
    >will cost.
    >Thank you for taking the time to read this letter.
    >John foster.27.7 .201.

  2. #2
    Senior Member giambjj's Avatar
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    Jul 2001
    Auburn, AL,USA

    4AP for your answers

  3. #3
    Senior Member
    Join Date
    Jul 2001
    The Netherlands


    I've e-mailed you an extensive article from Dr.Young about 4-ap from one year ago.I think it will take some time before it will be FDA approved because they still have to start a phase 3 trial.If you take 40 mg a day the costs are 80 dollar per month.If you are interested you can order them at the College Pharmacy('ve tried it as well but it didn't benefit me at all.

    btw; the website address is wrong it must be

  4. #4


    It is truly unfortunate that we do not have access to the Cando contents because I have posted over a dozen articles on the subject of 4-aminopyridine (4-AP) to that site. Let me try to summarize it briefly here and then place a longer article on the main CareCure site. Before I do so, let me first indicate that I was a founder of Acorda Therapeutics and was a member of their Board of Directors until recently. I currently belong to their Scientific Advisory Board. Acorda Therapeutics is developing a time-release version of 4-AP called fampridine and it is currently undergoing clinical trials.

    Mechanism of Action: 4-AP is a drug that has long been used by researchers to block voltage-sensitive potassium channels in neurons. The voltage-sensitive potassium channel limits the duration of action potentials or the signals that travel down axons. Increased action potential duration increases the likelihood that the signals will cross demyelinated areas on axons and also release more neurotransmitter at the end of the axons.

    Source of the Drug: The standard immediate release formulation of 4-AP can be obtained from compound pharmacies in the U.S. You will need a physician prescription and most compounding pharmacies in the U.S. will make the drug for you. The immediate release formulation is just a fancy way of saying that the drug is packed with filler material into a gelcap. Because the drug interacts with sucrose, it has a relatively short shelf-life and should not be purchased in large quantities. Several pharmacies claim to provide time-release formulations but none of these have been rigorously tested. I will focus only on the immediate release formulation here.

    Dose. Several clinical trials have suggested that 4-AP improves motor and sensory function in perhaps a third of people with chronic spinal cord injury. Most of these trials have given doses of the immediate formulation close to 10 mg every 6 hours. When taken orally, the immediate release formulation reaches peak blood levels within about 30 minutes and clears within 6 hours. Doses of the immediate release formulation that exceed 10 mg at a time and greater than 40 mg per day may lead to side-effects and an increased risk of seizure activity.

    Ramping: Recent experience suggest that the drug has the less side effects (see below) when the dose is ramped up slowly over a period of several weeks. One of the ways in which to do so is to start with 5 mg capsules, taking these once a day for three days, then twice a day for three days, four times a day for three days. If there are no side effects, one can then switch to 10 mg once a day for 3 days, twice a day for three days, and then four times a day for three days. Higher doses are not recommended due to the risk of seizures. Sensitivity to the drug varies. Some people may respond to the 5 mg 3-4 times a day.

    Tapering. Several people have reported increased spasticity when they stop the drug "cold turkey". Thus, when stopping the drug, you should taper the dose over a period of 1-2 weeks. For example, you should go from 10 mg every 6 hours to 10 mg twice a day for 3 days, then 5 mg twice a day for 3 days, and then off completely.

    Side-effects. I emphasize that 4-AP is not an innocuous drug. Because it blocks potassium channels in many tissues, including the heart and blood vessels, as well as the sympathetic and parasympathic nervous system, 4-AP may have effects of the physiology of many systems, including blood pressure and heart rate. At doses of less than 40 mg per day, relatively few serious side-effects have been reported. However, if you get a urinary tract infection which would reduce renal (kidney) clearance of the drug, this would raise the blood levels and produce side effects. I recently heard of an example of somebody with spinal cord injury who had gone up to 20 mg four times a day, suffered a urinary tract infection, and then developed status epilepticus (a dangerous form of seizure) that required hospitalization.

    Mechanism of action. 4-AP may improve conduction of demyelinated axons in people with chronic spinal cord injury. This is supposed to be its major mechanism of action. Therefore, if you do not have demyelinated axons or don't have sufficient axons crossing the injury site, the drug may have little or no beneficial effects on motor or sensory function. Several clinical trials have suggested that 4-AP can reduce spasticity and neurogenic pain although these findings have to be confirmed in larger and rigorously randomized clinical trials. The mechanism of such effects are not well understood. Obviously, because 4-AP increases excitability of axons, it may cause several side-effects including tingling or numbness around the lips, insomnia, and nervousness. Other effects that have been reported anecdotally include increased rate and number of bowel movements, improved bowel and bladder sphincter control, better respiration, less muscle fatigue, and improved sensations.

    Physician supervision. You should take 4-AP only under physician supervision. While College Pharmacy in Colorado and a number of compounding pharmacies will take a telephone prescription and then mail the drug to you in the United States or even overseas, please make sure that you work closely with a physician when you are taking 4-AP. I have heard many stories of people who, not understanding the ramping or the dosing, took inappropriate amounts of the drug. If you get side-effects, you need to have a physician who can take care of the side-effects.

    Time-release. As indicated above, some compounding pharmacies will sell a version of 4-AP that will release more slowly. A time-release formulation, for example, can be taken every 12 hours. Because the time-released drug does not reach as high a peak blood level as the immediate-release drug and produces a more stable consistent blood level, it should be more effective and have less side-effects.

    Efficacy. The benefits of 4-aminopyridine has yet to be established in a phase 3 clinical trial. Part of the reason for this is that only about a third of patients may be responsive to 4-AP, i.e. have demyelinated axons. Of those who are responsive to 4-AP, many may show benfit in one area but not the other. Clinical trials are seeking to establish the beneficial effects of 4-AP on multiple systems, including

    • reduced spasticity
    • increased muscle strength
    • reduced fatigue
    • improved touch and proprioception
    • reduced neurogenic pain
    • better bowel and bladder sphincter control
    • firmer erection and better orgasms
    • more frequent and easier bowel movements
    • better respiratory control

    Although there are a number of anecdotal reports from individuals indicating that the drug does have some of these benefits for them, none have been clearly demonstrated in well-blinded and randomized clinical trials.

    Usage of the Drug. Please note that the drug effect wears off within several hours, especially the immediate release formulation. In 1997, an informal survey by a drug company suggested that as many as 10,000 people in the United States are taking 4-AP regularly. There is no other recent statistics on use. Many of the people who take 4-AP have spinal cord injury. Last year, I polled people who were visiting the spinewire/cando forums and about 10% of 100 people that responded said that they were taking 4-AP.

    Please understand that this is not an innocuous drug, that it should be taken under the supervision of a knowledgeable physician, and that the 4-AP dispensed by pharmacies in gelcaps tend to have short half-lives and therefore should not be stored for periods of time exceeding 6 weeks.

    I was initially uncomfortable providing this information over Internet but was shocked by the number of people who were taking the drug inappropriately, without ramping or tapering, and without understanding the doses that they should be taking. If you have any further questions, please ask here. I will post a more comprehensive and documented article at the main CareCure site in a few days.


  5. #5
    Super Moderator Sue Pendleton's Avatar
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    Jul 2001
    Wisconsin USA
    I'd just like to repeat Wise's warning on being followed by a doctor while taking 4-AP. A baseline EKG should be taken before starting it in case of any troubles. When listing drugs you take for other than your main primary care physician or neurologist let them know 4-aminopyridine is a potassium channel blocker (in case they need to look it up). And talk to your doctor before taking any extra potassium supplements that an internet pharmacist might suggest. Too much potassium can harm the heart and it's the rare person that needs more than what we get in food. And if you get heartburn from it take it with food--I have too!

  6. #6
    Senior Member kngtreeman's Avatar
    Join Date
    Aug 2001
    naples florida usa
    i have writen the nimbers down as to wear i need to call to get 4 ap.i cpied and printed the post from wise about ramping up and ganna do this.i must i got nothin to question is .the drug remylinates existing the axons remain insulated after your done with the meds.or do they become uninsulated again after you stop taking thre drug and you return to wear you wer before

    scott r

  7. #7
    scott r,

    4-aminopyridine does not (to my knowledge) remyelinate the spinal cord. What it does is increase the excitability of demyelinated axons so that they will continue to conduct signals across the injury site. When you stop taking the drug, the increased excitability should go away and the axons no longer will conduct.

    Some people, however, have reported that as they use 4-aminopyridine for longer, there is a buildup effect on the motor responses. Whether this is due to reversal of learned non-use, improved muscle strength due to use, or remyelination is not clear.


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