@Ruthless Logic,
*Edit -- I spoke earlier this morning with a PharmD who is the head of our hospital pharmacy, and I also spoke with one of the senior cardiologists in our practice who has been in practice for about 30 or 40 years, and neither one has ever heard of phenytoin being used as an antiarrhythmic*
Getting accurate medical information as a layperson is very tricky, especially on the internet, because there isn't an easy way to know which sites are reputable and there isn't a peer-review process. You have had a difficult time differentiating the
actual clinical use of phenytoin from a
potential use that has been investigated but was never commonly used clinically. We spend a lot of time with patients trying to inform them and provide resources online and elsewhere with accurate information.
OUR main resource for accurate information is the National Library of Medicine, which has online access to the medical literature going back to around 1963. You can use various search engines like PubMed or Ovid to access it. We also use textbooks that have good
referenced reviews. For drug information the FDA requires that all package inserts include information about approved uses, toxicities, and other information. Phenytoin is NOT FDA approved for arrhythmias, as you will find by looking at the package insert that I linked. Its antiarrhythmic activity is class IB, and there are only a few class I antiarrhythmics in use anymore (like lidocaine, procainamide, a couple others) because better and safer drugs are out..
Ruthless Logic wrote:The claim that Phenytoin is NOT a cardiac drug is carelessly inaccurate. Phenytoin is used for certain Cardiac Arrhythmias (irregular rhythms). The link will directed you to ACCURATE information.
If you want accurate information, check MicroMedex, check PubMed, or call a cardiologist.
Phenytoin works on the brain by modulating ion channels. Turns out the heart has ion channels as well, and other antiarrhythmics work on the same site. Because of this there were early trials of phenytoin as an antiarrhythmic but as far as I can tell in PubMed, which catalogs all medical journal articles back to 1963 I can find NO evidence of it ever being used
clinically as an antiarrhythmic. The LAST published clinical trial of it for arrhythmias was published in 1988. It is not FDA approved for this indication and probably has not been even used off label for it for a generation. I've seen a lot of people with bad, refractory arrhythmias who are on multiple antiarrhythmics, and who have implanted defibrillators and pacemakers, and never once has phenytoin been part of the cardiologists' repertoire.
If you do a PubMed search, you'll find that nearly all the literature about phenytoin for arrhythmias comes from the late 1960s and early 1970s, with the most recent trial of
nine patients being in 1988. Why do I underline nine? Because most cardiology trials have
tens of thousands of patients. There is a national registry of clinical trials that you can check to see if someone is actually studying it. I believe you access it throug the NIH website.
Phenytoin is quite toxic and there are tons of safer alternatives. I've been certified in ACLS, PALS, and NALS/NRP several times each, I've worked in adult and pediatric ICUs, I've run resuscitations for people in cardiac arrest from arrhythmias, I am constantly consulting cardiologists, and never in my career has ANYONE ever regarded phenytoin as a viable therapeutic antiarrhythmic. So if it's actually used as an antiarrhythmic anywhere, it's either investigational or for extreme, refractory cases.
If you want independent corroboration of this, get away from Google and go ask someone else. Go find the chief of cardiology at your local hospital or a professor of cardiology at a local medical school. See how often they've used phenytoin to treat arrhythmias.
I'll do the same for you. I'll probably run across 5 to 10 cardiologists over the course of today at work. I'll ask them all.
Quote:I also find it disconcerting that a health care professional could possibly think that Distal Phalanges are immune to any disease processes.
Where pray tell did I say that? I didn't. In fact I have a patient right now with a Staph infection of his middle and distal phalanges of one finger, I recently had a patient with sickle cell disease who had sequestration in the distal phalanges, I've got a patient with RA with disease of the phalanges, and I've had a recent patient with endocarditis who had septic embolization to the distal phalanges.
I was responding to your
aphasic dribble "Phenytoin is used to treat most types of distal phalanges". You didn't say used to treat most types of
diseases of the distal phalanges (which would be ludicrous unto itself, because we think of diseases as PROCESSES, not PLACES). You said "most types of distal phalanges". Turns out that there are 20 types of distal phalanges -- one for each finger and toe. We also have middle phalanges and proximal phalanges.
Now which disease of the distal phalanges are you referring to? Are you referring to osteomyelitis? Onychomycosis? Sickle cell bone infarcts? Traumatic amputation? Frostbite? Osteosarcoma? Animal bites? Burn injuries? Osteoporosis? Osteogenesis imperfecta? Polydactyly? Diabetic ulcers?
These are hardly MOST types of diseases of your digits, but it should illustrate why you can't just speak of "most types of distal phalanges" as if its a disease that any doctor would recognize as such.
Like I said, you didn't refer to treating disease. You referred to treating anatomy.
Oh, and I'm still looking for a disease of the distal phalanges other than neuropathic pain that is routinely treated with phenytoin.
If you don't believe me, that's fine. I don't care. Everyone here has had a chance to see our respective credibility on this topic, decide for themselves, and then get on with their lives.
Now I'm going to lock this thread if this digression keeps going on, and that is a shame because it's a good philosophy topic. If you want to have a chat about pharmacotherapy, feel free to start a topic in the Lounge. Otherwise, let's get back on track.