Phenytoin therapeutic range
Common Questions and Answers about Phenytoin therapeutic range
dilantin
In a small study, phenytoin-induced seizures occurred most often in patients with serum phenytoin concentrations of 50 mcg/ml or higher.[393] Peripheral neuropathy, usually occurring weeks to months after drug initiation, has also been reported in patients receiving phenytoin. A single case report describes the onset of neuropathy within a few hours of drug administration.[9780]
Adverse GI effects of phenytoin therapy include nausea/vomiting, constipation, abdominal pain, and anorexia.
Hi there. Since your frequency of seizures has increased you need to have a fresh evaluation of your neurological function clinically, with a recent MRI brain and an EEG. The antiepileptic drugs need to be checked for a dosage modulation, assessment of adverse effects due to chronic usage over years like megaloblastic anemia, gingival hypertrophu and osteomalacia with phenytoin.
Take care.
Hello AB, welcome to the medhelp forum. Phenytoin can cause certain side effects like dizziness and mental confusion. Some people may also manifest incoordinate movements. Weight gain is not a documented side effect. It could be related to your alcohol consumption or wrong dietary habits and lack of exercise. An occasional one or two drink may be fine but moderate or large amount can cause significant increases in blood levels of phenytoin due to induction of hepatic enzymes.
Moban® brand of molindone hydrochloride contains calcium ions which interfere with the absorption of phenytoin. Ingestion times of phenytoin and antacid preparations containing calcium should be staggered in patients with low serum phenytoin levels to prevent absorption problems”. Taken from http://www.rxlist.com/cgi/generic/phenyt_od.htm
Our population is divided into 4 type of metabolizers ranging from rapid to slow metabolizers depending upon the speed of elimination of drug from body.
very good they are continuing research, rna interference was discovered years ago by a US company but after this discovery it was bankrapt because other durg makers sueing them, don t remember why i only remember they stopped everythign and even website of this company dissapered
so rnai research continued in israel and other countries outisde US, i am very happy to know that research is being conitued in china/australia where infuence of US drug makers is close to zero, especially china
rnai
Folic acid supplementation in folate-deficient patients with epilepsy changes the pharmacokinetics of phenytoin, usually leading to lower serum phenytoin concentrations and possible seizure breakthrough..."
It however says that initiation of Folic acid and phenytoin together is beneficial.
Since you can't go back and start all over again, you can take a small dose. It has been observed that as los as 1mg dose can perturb phenytoin’s levels, You may take doses lower than 1mg/day.
The efficacy of oral hypoglycemic agents and insulin may be diminished by certain drugs, including thiazides and other diuretics, corticosteroids, estrogens, progestins, thyroid hormones, human growth hormone, phenothiazines, atypical antipsychotics, sympathomimetic amines, protease inhibitors, phenytoin, clozapine, megestrol, danazol, isoniazid, asparaginase, pegaspargase, diazoxide, temsirolimus, as well as pharmacologic dosages of nicotinic acid and adrenocorticotropic agents.
The efficacy of oral hypoglycemic agents and insulin may be diminished by certain drugs, including thiazides and other diuretics, corticosteroids, estrogens, progestins, thyroid hormones, human growth hormone, gonadotropin-releasing hormone agonists, phenothiazines, atypical antipsychotics, sympathomimetic amines, protease inhibitors, phenytoin, megestrol, danazol, isoniazid, asparaginase, pegaspargase, diazoxide, temsirolimus, sucralfate oral suspension, as well as pharmacologic dosages of nic
Thank you for your question, you are relatively fine with Phenytoin and the seizure episodes in a form of lack of speech are the residue of a generalized type seizure. I don’t have a full description of your consciousness during the lack of speech episodes to decide whether this start is a partial epilepsy which can continue in a generalized or it is a generalized one from the first moment..
Lithium is one of those meds that you just have to play with. It's a trial and error type of med. Honestly, even a level of 0.9 is not therapeutic for bi-polar disorder. It should be at least 1.0 if not up to 1.5. And 0.6 is definitely not therapeutic. I was on 1500mg of Lithium once daily, extended release, and I still wasn't at a therapeutic range. Everyone is different. My metabolism just happens to metabolize lithium at a higher rate than it does for others. That might be your issue.
During those times I had not yet been diagnosed and was able to go back to life like normal, however after the diagnosis and being on phenytoin and switching to oxcarbazepine i am feeling awful. Dizzy, nauseated, moody, extremely tired, severe headaches that come and go. All i get from my Neurologist is these are side effects that will eventually go away. Because i never know when these symptoms will come on too strong I have missed a lot of days at work during my probation period.
My seizures were under control for a couple of years even thought my blood results said I was not within the therapeutic range. I moved out of state and my new doctor wanted to increase my dose's so I would fall with the range. I did not care at the time and
let her raise my dose.
Talking with my new neurologist who is the Newsome chair of epileptology and director of the Epilepsy Program told me that in short the therapeutic range is different for everyone.
I totally forgot to tell you that he is on Phenytoin 100mg once daily. Can this be continued and taken for a long period of time?
Thank you doctor once again for your immediate reply.
After joining the Forum and learning about the importance of FT3, I got mine tested and found that even though my FT4 was very high in the range, my FT3 was very low in the range.
After a med change to a combo T4/T3 med, my dosage has been tweaked until now FT4 is .90 (range is .60 - 1.50) and my FT3 is 3.8 (range is 2.3 - 4.2). I did not take meds until after the blood draw. Testing also showed a low level of Vitamin D, which is quite common with hypothyroidism, so I supplement that.
Your TSH really hardly moved. TSH can change by as much as 70% just depending on the time of day the blood was drawn. It's still above range, and AACE recommended many years ago that TSH range be changed to the much more reasonable 0.3-3.0.
FT3 and FT4 are much more important than TSH, especially once on meds. The target for FT4 is about 50% of range. Yours is at 24%. Target for FT3 is 50+% of range, and yours is 16%. So, you are still hypo.
It helps us in identifying whether the drug is in a therapeutic range or not. The decision of dosage adjustments depends on the doctor’s discretion and varies person to person. Do write to us again with more information.
Take care and good luck!
I only take 600mg lithium a day and my levels range from 0.5 to 0.7 which is well within the therapeutic range. Each person takes a different amounts and what is a good dosage for one person could send another person toxic or leave their blood lithium levels too low.
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