Phenytoin renal dosing
Common Questions and Answers about Phenytoin renal dosing
dilantin
Please note Tenofovir is principally cleared through the kidney and dosing adjustments due to renal impairment have not been clinically tested.
The followings are extracts from the label information for Tenofovir:
2.3 Dose Adjustment for Renal Impairment in Adults
Significantly increased drug exposures occurred when VIREAD was administered to subjects with moderate to severe renal impairment [See Clinical Pharmacology (12.3)].
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.
I am not aware that impaired renal function precludes treatment for HCV. I have read that kidney disease is a negative predictor of SVR but, so too are a lot of conditions yet people have overcome them. I have seen articles which discuss the plasma levels of ribavirin with renal impaired patients. The suggestion is that rather than weight base dose these patients the dose should be arrived at by considering GFR (glomerular filtration rate).
This is from Clinical Care Options @ http://tiny.
But nothing I see talks about swelling of hands as a symptom - which she also has (no rash on hands). On a sidenote she was recently diagnosed with renal artery stenosis, so I wonder if this isn't a vascular issue.
By "AGE" I'm assuming you mean a persons age in years. I don't believe age has anything to do with Janumet's "effectiveness" but age has a larger role with renal function. To make it clear for other readers, Janumet is combination of two drugs; Sitagiptin and Metformin.
This a brief from the Merck web site - makers of Janumet - Section 8.5 - Geriatric Use JANUMET.
I also have kidney damage from a bout of high blood pressure 4 years ago, and I am a frequent kidney stone former, so I am being watched carefully by a nephrologist too. I have renal panels frequently too. I was wondering if any of this could increase my stone risk. I was reading about the cytomel and stones. The nephrologist wants me to remain on the synthroid and cytomel.
I think it depends on some individual factors, particularly renal clearance of the drug. I found this information in the drug reference:
According to the manufacturer's tests, the drug reaches maximum serum levels between 15 and 44 hours after subcutaneous injection of a single dose. The mean elimination half-life is 22 to 60 hours (mean = 40 hours). So, I would expect that after 7 days (4.2 half-lifes) that the concentration would be about 5.5% (0.5^4.2) of the maximum levels.
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.
Glomerular filtration rate or its approximation of the creatinine clearance are measured whenever renal disease is suspected or careful dosing of nephrotoxic drugs is required. The normal ranges of GFR, adjusted for body surface area for males is 70 ± 14 mL/min/m2 (56-84) . Risk factors for kidney disease include diabetes, high blood pressure, family history and older age.
Take care and keep us posted.
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.
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..
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.
There are preferred opiates drugs that are use in patients with liver disease that have shorter half-lives and have less harmful side effects on the renal system. Your liver doctor should be aware of these drugs and be able to determine if you may be able to use them.
With regards to OTC medications, normal recommended doses of acetaminophen can be safely given to patients who suffer from cirrhosis in the short term.
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.
But regarding this Vit D , should i need to take along with calcium supllements Or no need? I have renal stones of 0.5mm. Does this have any effect on this?
If you are stage 3 you can take any analgesic within dosing limits. Your liver function has not been altered by your liver disease yet. If you become stage 4 (cirrhosis) then you will have to modify what drugs you can take because the liver is no longer able to process drugs in a normal manner.
Tramadol is an synthetic opiate and should not be taken for "mild" pain.
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.
Call your local pharmacist. We at MedHelp are not allowed to give out dosing instructions. Your pharmacist will be able to tell you exactly how to dose the medications. If your regular pharmacy is closed on Sunday, call any pharmacist availabe at your local grocery store or drug store such as Walgreens, CVS, or RiteAid.
RENAL RISK
TORADOL is CONTRAINDICATED in patients with advanced renal impairment and in patients at risk for renal failure due to volume depletion (see WARNINGS).
RISK OF BLEEDING
TORADOL inhibits platelet function and is, therefore, CONTRAINDICATED in patients with suspected or confirmed cerebrovascular bleeding, patients with hemorrhagic diathesis, incomplete hemostasis and those at high risk of bleeding (see WARNINGS and PRECAUTIONS).
Addition of other antiepileptic drugs like phenytoin,lamotrigene and sedatives will be helpful for controll of his night symptoms.
ROXICODONE® is intended for use in patients who require oral pain therapy with an opioid agonist. As with any opi-oid analgesic, it is critical to adjust the dosing regimen individually for each patient (see DOSAGE AND ADMINISTRATION).
Use of ROXICODONE® is associated with increased potential risks and should be used only with caution in the following condi-tions: acute alcoholism;adrenocortical insufficiency (e. g.
Recommended
