Urinary excretion of phenytoin and its metabolites. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. There have been two placebocontrolled studies in healthy men of the pharmacokinetic interaction of voriconazole with phenytoin 46 c. Phenytoin oral capsule is used to treat tonicclonic and complex partial seizures in people with epilepsy.
Phenytoin induces cyp3a4 activity and is a substrate and inducer of cyp2c9 and cyp2c19. Side effects of phenobarbital and phenytoin during longterm. Side effects that are less common but potentially dangerous can include swollen or tender lymph nodes, high blood sugar, and unexplained bruising or bleeding. Hematologic effects reported with use including agranulocytosis, leukopenia, pancytopenia, neutropenia, thrombocytopenia, and anemias. Iv phenytoin and dopaminemay cause additive hypotension. Phenytoin is highly proteinbound 90%, mostly to albumin. Antacids may decrease the absorption of orally administered phenytoin. A few possible side effects of phenytoin include insomnia, slurred speech, and gum problems. We present an unusual case that uniquely highlights both adverse effects of phenytoin on bone metabolism and side effects of its overtreatment. Most phenytoin is bound to protein in the bloodstream. Our dilantin phenytoin side effects drug center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
Dec 21, 2019 side effects not requiring immediate medical attention. The free phenytoin level is the best indicator of adequate therapy. As phenytoin is highly protein bound, free phenytoin levels may be altered in. Call your healthcare provider right away, if you have any of the symptoms listed above. The parameters used in the calculation include phenytoin measured and serum albumin. Phenytoin from binding sites, creating a transient phenytoin toxicity with no change in total but an increase free phenytoin level. In renal failure, the opportunity for the free phenytoin fraction to be cleared is significantly reduced. Ten percent of the phenytoin circulates in the free, unbound form. Phenytoin can have opposite side effects from minor blood levels to toxic blood levels, somewhat the inverse of alcohol, esp. Dilantin phenytoin is an antiepileptic drug, also called an anticonvulsant, used to control seizures. Therapeutic effectwithout clinical signs of toxicity occurs more. Serious sideeffects include blood dyscrasias and skin disorders such as exfoliative. The effect was probably related to displacement of phenytoin by free fatty acids. This medicine is available in different forms, including dilantin, phenytek, or generic phenytoin.
However, this medicine can make absence or petit mal seizures happen more frequently. You are free to copy and communicate the work in its current form for noncommercial purposes, as long as you attribute the state of. Hypersensitivity and dose related side effects of phenytoin. Find information on phenytoin dilantin, phenytek in daviss drug guide including dosage, side effects, interactions, nursing implications, mechanism of action, half life, administration, and more.
One of its main advantages over benzodiazepines is the less sedative effect. Since phenytoin is highly proteinbound and free unbound phenytoin is the component producing the pharmacological effect, any factor which changes the protein binding of phenytoin would be expected to alter the free drug levels. Because it interferes with vitamin d metabolism, phenytoin can cause weakening of the bones osteomalacia. Phenytoin can cause rare, severe cutaneous adverse reactions scars such as. Need to get regular blood tests while taking dilantin phenytoin to make sure the medicine level is safe and effective in your body. Therapeutic drug monitoring of phenytoin is carried out to ensure effective and safe levels. You are free to copy and communicate the work in its current form for noncommercial purposes, as long as you attribute the state of queensland, queensland ambulance service and comply with the licence terms.
If you experience a rash while taking dilantin or any of the symptoms listed below, contact your doctor immediately. This is not a complete list of side effects and others may occur. Phenytoin sodium capsules oral dilantin side effects. Monitoring of phenytoin concentration among patients with chronic use will be helpful in prevention, early identification and resolution of.
On the other hand, cardiovascular toxicity is the main side effect of. Because of its effect on ventricular automaticity, dilantin is. This emedtv page lists other phenytoin side effects that may occur, including potentially serious side effects that should be reported to a doctor right away. Dilantin phenytoin is very good at treating and preventing seizures, but it has many drug interactions and some serious side effects. Phenobarbital may cause hyperactivity, behavioral problems, sedation, and even dementia. Learn about side effects, warnings, dosage, and more. A serious, lifethreatening disorder called stevensjohnson syndrome and drug reaction with eosinophilia and systemic symptoms dress, which can be fatal. Common and rare side effects for dilantin intravenous. Learn about phenytoin from patients first hand experiences and trusted online health resources, including dosage, side effects and interactions. The dose is the same for all phenytoin products when initiating therapy.
Find information about common, infrequent and rare side effects of dilantin intravenous. A blockage of the bile duct that resulting in high bilirubin levels. If total concentration is above upper range but below 30 mgl 120 micromoll, withhold dose. Call your doctor for medical advice about side effects. Dec 11, 2018 the free acid form of phenytoin is used in dilantin125 suspension and dilantin infatabs. Side effects requiring immediate medical attention. Dilantin phenytoin side effects, dosage, interactions. Hypersensitivity syndrome usually occurs at 38 wk but may occur up to 12 wk after initiation of therapy. Cyp450 pathway, both leading to increased amounts of free phenytoin in the serum. Because of rapid equilibration between free and bound portions of drugs, free levels are potentially important only in aeds that are highly bound ie, phenytoin but not carbamazepine. Rash usually occurs within the first 2 wk of therapy. We present three cases each with a characteristic side effect of the. Dilantin extended capsules and parenteral dilantin are formulated with the sodium salt of phenytoin. Dec 11, 2018 our dilantin phenytoin side effects drug center provides a comprehensive view of available drug information on the potential side effects when taking this medication.
Side effects of phenobarbital and phenytoin during longterm treatment of epilepsy. Phenytoin causes dose related side effects at normal doses on chronic use. Side effects of phenobarbital and phenytoin during long. Other important side effects caused by phenytoin include sexual dysfunction. When the body has reached its capacity to process phenytoin, small increases in the dose can cause large increases in blood concentration, increasing the severity of side effects and causing phenytoin toxicity.
Increased free phenytoin produces an enhanced pharmacologic effect. As such, interactions with other drugs drugdrug interactions or with diseases e. Anticonvulsant induced osteopathy can have detrimental consequences. May render ocps ineffective because of induction of hepatic metabolism. Read more about the prescription drug phenytoin sodium capsules oral. Three patients with dystrophia myotonica and echocardiographic signs of subclinical cardiopathy had cardiac side effects during oral treatment with phenytoin sodium or carbamazepine. Pdf phenytoin is an established drug in the treatment of acute repetitive seizures and status epilepticus. Along with its needed effects, phenytoin may cause some unwanted effects.
Phenytoin induced toxicity leads to ataxia, nystagmus, gingival hypertrophy, nodular skin lesions and hirsutism. Most of the drug is excreted in the bile as inactive metabolites which are then reabsorbed from the intestinal tract and excreted in the urine. Finally, the results support the use of a higher volume of distribution when calculating the effects of dosing changes of phenytoin. These are not all of the possible side effects of dilantin. Clinical guideline for the use of phenytoin in epilepsy final. If you alter the work, you may not share or distribute the modified work. For dilantin capsules, peak serum levels occur 4 to 12 hours after administration. Suggests clinical disorders or settings where the test may be helpful. However, the possibility of cardiovascular adverse effects with the intravenous use of phenytoin cause a reluctance to its usage, and this has lead to a search for safer anticonvulsant drugs. Anticonvulsants have the broad spectrum of side effects on the bone that are collectively known as osteopathy. Hypotension, bradycardia, cardiac arrhythmia, cardiovascular collapse especially with rapid i. The complete but practical guide to phenytoin dosing tl.
Preparations containing phenytoin sodium are not bioequivalent to those containing phenytoin base such as epanutin infatabs and epanutin suspension. Phenytoin extended capsule oral dilantin side effects. High levels of dilantin in your blood that could cause confusion also known as delirium, psychosis or a more serious condition that affects how your brain works encephalopathy. People who have just started taking phenytoin or who have just started taking a larger amount should be careful during activities that might be dangerous, until they know whether they are having any side effects. Clinical considerations 1,2 wash hands if contact is made with the medication to prevent contact dermatitis. Dilantin phenytoin side effects, dosage, interactions drugs. Additive cns depression with other cnsdepressants, including alcohol, antihistamines, antidepressants, opioids, and sedativehypnotics. Phenytoin sodium is related to the barbiturates in chemical structure, but has a fivemembered ring. See what others have said about dilantin, including the effectiveness, ease of use and side effects. Pdf cardiovascular adverse effects of phenytoin researchgate.
Consumer information about the medication phenytoin sodium capsules oral dilantin, includes side effects, drug interactions, recommended dosages, and storage information. Antacids mayp absorption of orally administered phenytoin. Side effects of dilantin phenytoin, warnings, uses rxlist. Peak levelsindicate an individuals threshold for emergence of doserelated side effects and are obtained at the time of expected peak concentration. Monitor closely for notable changes in behavior that could indicate the emergence or worsening of suicidal thoughts or behavior or depression. Some side effects may occur that usually do not need medical attention. The below strategy back calculates total levels by rearranging the above ff equation and inputting free levels of 1 and 2 mcgml, since that is the range of free levels we know to be therapeutic. The calculator for phenytoin free unbound drug level adjusted for hypoalbuminemia is used to predict the unbound, free phenytoin level in patients with hypoalbuminemia. Allergic reactions approximately 1 in 10 people who take phenytoin have a red rash within the first few weeks of taking it. Cardiac side effects of phenytoin and carbamazepine.
Route onset peak duration phenytoin itoyn po 224hr1wk. The free acid form of phenytoin is used in dilantin125 suspension and dilantin infatabs. Typical free phenytoin is onetenth of total phenytoin as phenytoin is 90% protein bound. Sexual side effect of dilantin epilepsy foundation. Each dilantin 100 mg extended oral capsulecontains 100 mg phenytoin sodium. Phenytoin should be administered into a large vein and flushed. Read more about the prescription drug phenytoin extended capsule oral. If experienced, these tend to have a severe expression. The free acid form of phenytoin is used in dilantin 125 suspension and dilantininfatabs. Phenytoin is commonly used antiepileptic drug having variety of side effects. The first was an open study of the effect of phenytoin 300 mgday on the steady. The complete but practical guide to phenytoin dosing.
Increased risk of suicidal thoughts or behavior reported. Dbl phenytoin injection bp is a clear, colourless solution, free from visible particulates. It should be used cautiously as it has narrow therapeutic index. Dilantin may cause serious side effects, including. Interactions may decrease the effects of delavirdine. Confusion, muscle coordination problems, and unusual eye movements are some of the most common side effects reported with dilantin. See below for a comprehensive list of adverse effects. No cardiovascular adverse effect was reported in oral phenytoin overdoses except one case with a. Phenytoin complete drug information, side effects and. Phenobarbital and phenytoin have good antiepileptic effect, but clinically significant untoward effects occur during their longterm use. Phenytoin acts by inhibiting this enzyme, thereby causing folate deficiency, and thus megaloblastic anemia. Dieter schmidt, stefan beyenburg, in side effects of drugs annual, 2009.
Consumer information about the medication phenytoin extended capsule oral dilantin, includes side effects, drug interactions, recommended dosages, and storage information. The chemical name is sodium 5,5diphenyl2, 4imidazolidinedione, having the following structural formula. Free phenytoin is the active form of the drug, available to cross biologic membranes and bind to receptors. Additive cns depression with other cnsdepressants, including alcohol, antihis tamines, antidepressants, opioids, and sedativehypnotics. These side effects may go away during treatment as your body adjusts to the medicine. According to the prescribing information available for dilantin, the brandname of phenytoin, dilantin can cause rare, but serious, side effects including exfoliative dermatitis, stevensjohnson. Side effects of phenytoin nervous system home page. Phenytoin can cause the platelet or white blood cell counts to drop, increasing the risk of bleeding or infection, respectively. These interactions may potentially affect the level of phenytoin in your blood, raise your risk of side effects, or decrease the effectiveness of some medicines. Dilantin extended oral capsules phenytoin dosage and. To describe phenytoininduced rare hypersensitivity and dose related reactions, emphasizing the importance.
The more common side effects that can occur with phenytoin include. On this page about phenytoin sodium sandoz you will find information relating to side effects, age restrictions, food interactions, whether the medicine is available at a government subsidised price on the pharmaceutical benefits scheme pbs as well as other useful information. The free acid form of phenytoin is used in dilantin 125 suspension and dilantin infatabs. The end result is that both the total and free concentration of phenytoin increase, with the free concentration increasing faster than the total. Side effects hypotension bradycardia av heart block cns depression nausea andor vomiting. Phenytoin induced osteopathy too common to be neglected. As phenytoin is highly protein bound, free phenytoin levels may be altered in patients whose protein binding characteristics differ from normal. Some side effects of phenytoin may occur that usually do not need medical attention. Therapeutic levels of phenytoin are 4080 umollitre.
Because there is approximately an 8% increase in drug content with the free acid form over that of the sodium salt, dosage adjustments and serum level monitoring may be necessary when switching from a product formulated with the free acid to a product. This case report includes a case of phenytion induced. Find patient medical information for phenytoin oral on webmd including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Monitoring for appropriate therapeutic concentration of both free and total phenytoin. Phenytoin is 90% bound, but only the free fraction circulates through plasma membranes and is biologically active. In addition, they suggest that checking the serum level of phenytoin sooner than 2 weeks after a dose change, in either older or younger adults, will underestimate the effect of the change. Drug interactions with phenytoin certain medications including paroxetine, cimetidine, and carbamazepine may potentially cause drug interactions with phenytoin. Be alert for phenytoin hypersensitivity syndrome fever, skin rash, lymphadenopathy.
Since its discovery in 1908, phenytoin has become one of the most. A guide to therapeutic drug monitoring sage journals. Phenytoin dilantin, dilantin 125 is an oral and injectable drug prescribed for the treatment of seizures. Seizure treatment dilantin extended phenytoin sodium. Phenytoin is a potent inducer of hepatic drugmetabolizing enzymes. Loading dose of 10 15mgkg phenytoin by iv infusion.