PHENYTOIN
Chapter: Nootropics
Read about PHENYTOIN in "Drug safety during pregnancy and breastfeeding" section
AKA: Dilantin (extended action), Diphenylan (prompt acting), Diphenylhydantoin (DPH), Ditan (prompt acting), Ethotoin, Mephenytoin, Mesantoin, Peganone, Phenytex, PHT.
The most commonly prescribed drug for epilepsy, it has been the subject of at least 8000 papers. The exact mechanism by which it works is still not understood, but it is believed to influence the electromagnetic fields, polarizing the electrically charged elements of the cells.
Effects: Though it is mainly used as a treatment for epilepsy, it has a number of other various
Effects: it can normalize electrical activity in the cell membranes; it can stabilize behavior by suppressing obsessive thoughts, fear, anger, violent behavior, and passivity; it can supposedly improve intelligence, concentration, learning, long-term memory, comprehension, and speed of visual-motor coordination; it has some anti-aging effects, including restoring the homeostasis of the neuroendocrine system; in small doses, it increases the "good" form of cholesterol, called high density lipo-protein (HDL).
Precautions: It is not taken by anyone who is allergic to hydantoin anticonvulsants, has liver damage or impaired liver functioning, has had surgery within the last two months that has required general or spinal anesthesia, has diabetes, or a blood disorder. Those over 60 should realize that adverse reactions and side effects will occur more often and much more strongly than they do in younger individuals.
Common side effects include constipation; mild dizziness; drowsiness; gums that are bleeding, swollen, or tender; nausea; increased susceptibility to sunburn; and vomiting. Less common side effects include agitation, breast swelling, confusion, diarrhea, an increase in facial and body hair, hallucinations, headaches, insomnia, muscle twitches, rash, slurred speech, staggering, vision changes. Rare symptoms include abdominal pain, an increased chance of bleeding or bruising, fever, jaundice, and sore throat. Other symptoms cited by some sources include anemia, balding, chest pains, depression, mental confusion and learning disability, conjunctivitis, nervousness, numbness of the hands and feet, nystagmus, retention of water, sensitivity to bright lights, swollen glands, tiredness, irritability, and weight gain, though these also disappear as time goes on and dosage is reduced. A severe allergic reaction could be life-threatening, and could include such symptoms as fever, rash, swollen glands, and kidney failure. Use of phenytoin may even cause liver damage, including hepatitis. If stomach upset occurs, it should be taken with meals. Long-term effects may be weakened bones, gum overgrowth (though this occurs mainly in children and is rare in instances where the lower, cognitive-enhancing doses are taken; still, good oral hygiene is recommended), constant eye movements, liver damage, lymph gland enlargement, and numbness and tingling in the hands and feet.
An overdose can cause problems in maintaining balance, a drop in blood pressure, slow, shallow breathing, coma, drowsiness, spastic eye movements, decreased intelligence, slow reaction time, slurred speech, and staggering. There have been reports of insomnia, tremors and in some cases, liver toxicity in the first month or so of use. It is not habit-forming, but abrupt cessation could trigger severe epileptic seizures.
Phenytoin may deplete the body's stores of B-12, lead to a heightened need for thyroid hormone, interfere with the absorption of vitamin D and folic acid (supplements of calcium should be taken along with vitamin D and folic acid, though calcium will decrease the amount of Phenytoin the body absorbs from the small intestine).
The effects of Phenytoin can be increased when taken with alcohol (small amounts), Allopurinol, salicylate drugs such as aspirin, benzodiazopine tranquilizers and sedatives, Chlorphi-ramine, Cimetidine, Ibuprofen, Metro-nidazole, Miconazole, Molindone, Nizatidine, Omeprazole, Phenacemide, succinimide antiseizure medicines, tri-cyclic antidepressants, Trimethoprim, or Valproic Acid. The anticonvulsant effect can be enhanced when taken in combination with Amiodarone, Carba-mazepine, Chloramphenicol, Disul-firam, Fluconazole, Isoniazid, Methyl-phenidate, Nicardipine, Nimodipine, Oxyphenbutazone, Para-aminosalicylic acid (PAS), Phenothiazines, Phenylbutazone, Sulfa drugs, or Warfarin. The anticonvulsant effect is diminished when Phenytoin is taken with alcohol (habitual use), antacids, anticancer drugs, barbiturates, Carbamazepine, charcoal tablets, Diazoxide, Glutethimide, influenza virus vaccine, Loxapine, marijuana (with attendant drowsiness and unsteadiness), Nitrofurantoin, Paroxitine, Pyridoxine, Rifampin, Sucralfate, or Theophylline. When taken in combination with anticoagulants or Propafenone, the effects of both drugs are intensified, and when taken with Xanthines, the effects of both drugs are weakened. Phenytoin can amplify the effects of Estrogen, Griseofulvin, Methotrexate, Propranolol, Quinidine, sedatives, and Warfarin, and curtail the effects of Amiodarone, Carbamazepine, corticosteroids, cortisone drugs, Cyclosporine, Dicumarol, Digitalis preparations, Disopyramide, Doxycycline, Furosemide, Haloperidol, Hypoglycemics, Itraconazole, Methadone, Metyrapone, Mexiletine, oral contraceptives, potassium supplements, Probenecid, Quinidine, Sotalol, Theophylline drugs, and Valproic Acid. Phenytoin can interact unpredictably with Clonazepam, Dopamine, levodopa, Levonorgestrel, Mebendazole, Phenothiazine antipsychotic medicines, or oral antidiabetic medications.
The severity of side effects and adverse reactions increases when taken with Felbamate, there is an increased risk of toxicity when taken with Cimetidine, and an increased risk of liver toxicity when taken with Acetaminophen. The anticonvulsant dose may need to be adjusted when taken with tricyclic antidepressants; there may be a changed seizure pattern when taken with barbiturates; there is a greater chance of bone disease when taken with carbonic anhydrase inhibitors; there could be oversedation when taken with central nervous system depressants; the incidence of seizures increases when taken with cocaine or oral contraceptives; corticosteroid drugs could hide any Phenytoinsensitivity reactions; there could be an increase in drug levels in the blood when taken in combination with gold compounds; and Leucovorin could counteract the effects of phenytoin. When taken with Lithium, it can increase the toxicity of the latter drug; when taken with MAO inhibitors, it could result in an increased polythiazide effect; when taken with Meperidine, it can decrease the painrelieving effects of the latter while increasing its side effects; when taken with nitrates, it could result in an excessive drop in blood pressure; when taken with Omeprazole, there could be a delay in the excretion of phenytoin with a resultant excess remaining in the blood; when taken with Phenacemide, it could result in an increased risk of paranoia; and when taken with Valproic acid, it could result in seizures.
Dosage: Adult epileptics are generally given doses of 200 to 400 mg/day in two to four divided doses. About an eighth of that, or 25 to 50 mg/day are given for cognitive-enhancing effects, though some recommend as much as 100 mg/day in two to four divided doses.
Questions and Answers
What are the possible affects of reducing Phenytoin?, I've been taking 275mg of phenytoin for 22 years now. Since I started taking lamotragine alongside it, my seizures have reduced dramatically and the neurologist wants to get me off the phenytoin altogether. I'll be reducing it by 25mg each week. What side affects am I likely to notice - am I likely to feel more anxious, jittery or short-tempered for a while?
I switched from Dilantin (phenytoin) to Lamictal (lamotragine) 5 years ago taking both at the same time during the switch; reducing Dilantin and ramping up Lamictal. I don't recall having any side effects during the switch. Looking back, I was definitely more aware of the fact that I was taking Dilantin, I would feel "weird" if I missed a dose or took it late. I don't have any of that with the Lamictal. I haven't had a seizure in 7 years. I went in to get blood work during the switch so they could keep track of the levels in my system. It's not a bad idea to also keep track of how you're feeling too.
Can the abortion pill be taken whilst on phenytoin?, Phenytoin is an anti-eptileptic drug (epinutin) Is this less likely to make the abortion pill work?
Please no judgemental answers, this choice has not been made selfishley!
Sorry, I do not know.
But, I think you're best bet is to phone NHS 24 and ask them, or ask your doctor. They will be able to give you a correct answer.
How do u calculate the rate of150 mg of phenytoin if the rate is not exceeding of 1mg/kg/min?, Epileptic patient is 10kg, loading dose is 10-15 mg/kg. what is prescribe dose? how do you calculate the rate of phenytoin if the rate not exceeding 1mgkg/min
Hai Weweng,
Hope, we have met before.
Here the answer,
Patient weight: 10 kgs
Loading dose :15mg/kg
Therefore, the dose you required as per weight is
15mg * 10kg = 150mg.--------- I
Rate of infusion = 1mg/ kg/mt
Therefore, it is 10mg per minute.(for 10kg)------------ II
From I & II
10 mg over ----------------a minute
Therefore 150mg---------------- (1/10) * 150
......which, gives you 15 minutes.
That means, you need to run 150 mg of phenytoin over 15 minutes, in order to ensure that, you are giving at 1mg/kg/mt.
In order to do that, dilute 150mg of phenytoin in 50mls of Nacl(0.9) in a syringe and run it through a syringe driver at the set rate of 200mls per hour. So that, it will finish by 15 minutes.
Hope, this helps
What are the long term effects of taking the anti seizure medication phenytoin?,
These side effects may be a result of long term use of the medication phenytoin: insomnia, headache, measles-like rash, coarsening of facial features, enlargement of lips,and increase in facial and body hair .
It can also cause drug induced lupus and collagen vascular disease and can alter vitamin and minerals levels.
The loading dose of phenytoin for a child is 20mg/kg. What is the dose for a child weighing 32 pounds?, Please help me through this problem. Ty
290.9 mg
32lbs/2.2 = 14.54kg
14.54kg x 20mg/kg = 290.9 mg
How does phenytoin(for epilepsy)afects?, My husband is epileptic and he takes phenytoin.Because of that it's very rare that we have sex (it's a side effect.men loose desire)Now i want to try to conceive.Can i conceive when we have sex and he doesn't have any orgasm?
There is a difference between orgasm and ejaculating. It is a myth that everytime a man has sex he orgasms. He should however ejaculate with sex (although it is possible that he doesnt). Normally (if sperm count is normal) he should ejaculate 1 to 2 tsps. in order to have enough sperm to impregnate you. But it only takes 1 sperm to do the job so it's possible for it to be released during pre-ejaculate. He should definitely talk to his doctor and have his sperm tested. Maybe the doctor could prescribe something to increase his sex drive. I wish you all the luck in the world. Having a child is a blessing from God and only he knows when the time is right. Baby Dust to all Trying to Conceive.
What would happen if someone took Dilantin (Phenytoin) if they didn't have seizures?, I would like to know what kinds of side effects would likely occur in this situation. No, I am not considering taking it and this is not about myself. Medical facts only please. Thank you.
If a commonly prescribed dose was taken the person might get drowsy, feel physically weak, nauseated (these are also side effects for those who take it and do have seizures as well).
It could also cause foul smelling urine and could affect the liver.
All of this is off the top of my head what I remember in pharmacology class.
It can also cause vascular irregularities (in effect, could affect a person's heart).
The least that could happen is really nothing aside from a little drowsiness.
The worst that could happen is an allergic reaction leading to anaphalactic shock and death.
But I've also known people who have taken it for recreation and they only took it one time because they said it made them feel too sick.
usage of Phenytoin (Dilantin) for treating such symptoms?, Apart from the treatment for epilepsy, has anyone used Phenytoin (Dilantin) for the treatment of the following symptoms? And if you have how much did it benefit your symptoms?
Obsessive / racing thoughts, Anger, Anxiety, Rage, Depression.
** I have heard that Phenytoin is said to treat over 100 symptoms of misc diseases. But i don't know of the efficacy to this statement.
IF YOU EVER HEAR THAT THE MEDICATION WORKS ..PLEASE EMAIL ME
AT BiGScareYCaTFoRLiLMisSxSexYKittY@yahoo.c... Thanks , darren
P.S. i am bipolar and i need a cure and i need help
is there any article which says about animal models of phenytoin induced diabetes?,
These may help.
http://www.medscape.com/medline/abstract...
http://www.pubmedcentral.nih.gov/article...
Will someone PLEASE lay out the symptoms of phenytoin poisoning in layman's terms?,
Symptoms:
* Body as a whole
o Unsteadiness
o Swollen gums
o Fever
o Tremor
o Convulsions (occasionally)
o Rigidity
* Eyes, ears, nose, and throat
o Nystagmus (side-to-side eye movement)
* Heart and cardiovascular
o Low blood pressure
* Nervous system
o Sleepiness
o Confusion
o Slurred speech
o Dizziness
o Coma
