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Journal of Neurology, Neurosurgery, and... Jul 1988A prospective, double-blind, placebo-controlled investigation of possible withdrawal symptoms from phenytoin, carbamazepine and sodium valproate is reported in patients... (Clinical Trial)
Clinical Trial
A prospective, double-blind, placebo-controlled investigation of possible withdrawal symptoms from phenytoin, carbamazepine and sodium valproate is reported in patients with active epilepsy, on combination therapy. There was an increase in seizures on reduction and withdrawal of carbamazepine, but there was no convincing evidence of withdrawal symptoms from any of these drugs.
Topics: Adolescent; Adult; Aged; Carbamazepine; Clinical Trials as Topic; Double-Blind Method; Drug Therapy, Combination; Epilepsy; Female; Humans; Male; Middle Aged; Phenytoin; Prospective Studies; Substance Withdrawal Syndrome; Valproic Acid
PubMed: 3144581
DOI: 10.1136/jnnp.51.7.924 -
Epilepsia 2006The elderly are the most rapidly growing segment of the population and the incidence of epilepsy is higher in the elderly than in any other age group. They have been... (Comparative Study)
Comparative Study
The elderly are the most rapidly growing segment of the population and the incidence of epilepsy is higher in the elderly than in any other age group. They have been subdivided into the "young old," 65-74 years, "middle old" 75-84 years, and the "old old," 85 years or older. But further subdivisions are needed: persons with only epilepsy, those with epilepsy and multiple medical problems, and the frail elderly. Thus, when considering therapy, one must tailor the interventions to nine categories: young old healthy, young old with medical problems, frail young old, old healthy, old with medical problems, frail old, old old healthy, old old with medical problems, and frail old old. The prevalence of antiepileptic drug (AED) use in community dwelling elderly is 1.5%; in the nursing home population it is 10%. Surprisingly, 3% have an AED newly prescribed after admission. Overall, 6.2% were using phenytoin, 1.8% carbamazepine, 0.9% valproic acid, 1.7% phenobarbital, and others combined, 1.2%. AEDs rank fifth among all drug categories as a cause of adverse reactions. There are very few data regarding the clinical use of AEDs in the elderly. The paucity of information makes it very difficult to recommend specific AEDs with any confidence that the outcomes will be optimal. An appropriate for elderly healthy may not be appropriate for elderly with multiple medical problems, and in frail elderly variable absorption may be a major problem. One of the major advantages of some newer AEDs is lack of drug interactions. Cost is an advantage of the older AEDs. Regardless of the AED chosen, one must use doses appropriate to the clearance of the drug, and AED levels, especially unbound (free) levels, must be monitored. The elderly nursing home resident may be more frail, be taking many medications, and have several concomitant illnesses, making them difficult to treat. The most commonly used AED, phenytoin, may not be the easiest or safest AED to prescribe in the elderly with multiple medical problems or the frail elderly.
Topics: Adult; Age Distribution; Aged; Aged, 80 and over; Anticonvulsants; Comorbidity; Drug Costs; Drug Interactions; Epilepsy; Frail Elderly; Humans; Middle Aged; Nursing Homes; Phenytoin; Practice Patterns, Physicians'; Treatment Outcome
PubMed: 17044830
DOI: 10.1111/j.1528-1167.2006.00664.x -
BMJ (Clinical Research Ed.) Oct 1995To determine effectiveness and adverse effects of anticonvulsant drugs in management of pain. (Clinical Trial)
Clinical Trial Randomized Controlled Trial Review
OBJECTIVE
To determine effectiveness and adverse effects of anticonvulsant drugs in management of pain.
DESIGN
Systematic review of randomised controlled trials of anticonvulsants for acute, chronic, or cancer pain identified by using Medline, by hand searching, by searching reference lists, and by contacting investigators.
SUBJECTS
Between 1966 and February 1994, 37 reports were found; 20 reports, of four anticonvulsants, were eligible.
MAIN OUTCOME MEASURES
Numbers needed to treat were calculated for effectiveness, adverse effects, and drug related withdrawal from study.
RESULTS
The only placebo controlled study in acute pain found no analgesic effect of sodium valproate. For treating trigeminal neuralgia, carbamazepine had a combined number needed to treat of 2.6 for effectiveness, 3.4 for adverse effects, and 24 for severe effects (withdrawal from study). For treating diabetic neuropathy, anticonvulsants had a combined number needed to treat of 2.5 for effectiveness, 3.1 for adverse effects, and 20 for severe effects. For migraine prophylaxis, anticonvulsants had a combined number needed to treat of 1.6 for effectiveness, 2.4 for adverse effects, and 39 for severe effects. Phenytoin had no effect on the irritable bowel syndrome, and carbamazepine had little effect on pain after stroke. Clonazepam was effective in one study for temporomandibular joint dysfunction. No study compared one anticonvulsant with another.
CONCLUSIONS
Anticonvulsants were effective for trigeminal neuralgia and diabetic neuropathy and for migraine prophylaxis. Minor adverse effects occurred as often as benefit.
Topics: Anticonvulsants; Carbamazepine; Clonazepam; Diabetic Neuropathies; Humans; Pain; Phenytoin; Treatment Outcome; Trigeminal Neuralgia; Valproic Acid
PubMed: 7580659
DOI: 10.1136/bmj.311.7012.1047 -
British Medical Journal Feb 1978We performed prospective trials of phenytoin and carbamazepine, assisted by blood level monitoring, in untreated patients newly referred with grand mal or partial... (Clinical Trial)
Clinical Trial Comparative Study
We performed prospective trials of phenytoin and carbamazepine, assisted by blood level monitoring, in untreated patients newly referred with grand mal or partial seizures, or both, to a neurological clinic. At the time of follow-up (mean 28.5 months for phenytoin; 12 months for carbamazepine) 76-88% of patients were completely controlled. Twelve per cent of the patients on each drug had further seizures, despite an optimum blood level. When the blood drug concentration was in the optimum range there was a 98% reduction in grand mal attack rate and 92-93% reduction in partial seizure rate. These results suggest that polypharmacy is largely, and possibly totally, unnecessary in newly diagnosed adult epileptics.
Topics: Adolescent; Adult; Aged; Carbamazepine; Child; Epilepsy; Female; Humans; Male; Middle Aged; Phenytoin; Prospective Studies
PubMed: 626839
DOI: 10.1136/bmj.1.6111.474 -
Tidsskrift For Den Norske Laegeforening... May 2003The review defines status epilepticus and discusses treatment options for convulsive and nonconvulsive status epilepticus. The drug of choice in Norway is diazepam...
The review defines status epilepticus and discusses treatment options for convulsive and nonconvulsive status epilepticus. The drug of choice in Norway is diazepam intravenously (0.25 mg/kg), followed by phosphenytoin or sodium valproate intravenously and barbiturate narcosis. Other treatment options are discussed. Underlying causes must be addressed for therapeutic intervention. Given early treatment, the prognosis is generally good.
Topics: Adult; Anticonvulsants; Diazepam; Humans; Phenytoin; Status Epilepticus
PubMed: 12822018
DOI: No ID Found -
Journal of Pain and Symptom Management Apr 1993Trigeminal neuralgia is not common, but is a debilitating pain syndrome. After the diagnosis is established, a stepwise approach to treatment is recommended....
Trigeminal neuralgia is not common, but is a debilitating pain syndrome. After the diagnosis is established, a stepwise approach to treatment is recommended. Carbamazepine is the drug of choice. When carbamazepine fails to relieve pain, baclofen and then phenytoin are used. A number of second-line drugs, such as clonazepam, divalproex sodium, chlorphenesine carbamate, and pimozide can also be tried. A large number of patients will respond to one or another drug or to a combination of two drugs. When medical treatment fails, several surgical procedures have been found to be effective. Percutaneous radiofrequency gangliolysis is the most widely used procedure with a high success rate. All surgical procedures must be performed by an experienced physician in order to achieve the lowest possible rate of serious complications.
Topics: Baclofen; Carbamazepine; Diagnosis, Differential; Humans; Phenytoin; Trigeminal Neuralgia
PubMed: 8326165
DOI: 10.1016/0885-3924(93)90143-j -
Journal of Neurology, Neurosurgery, and... Feb 1969
Topics: Carbamazepine; Contracture; Electromyography; Humans; Male; Myotonia; Phenytoin
PubMed: 5774127
DOI: 10.1136/jnnp.32.1.11 -
Postgraduate Medical Journal Dec 2003Cross reactivity between phenytoin, carbamazepine, and oxcarbazepine is reported. An 8 year old boy with partial seizures developed maculopapular rashes with itching on... (Review)
Review
Cross reactivity between phenytoin, carbamazepine, and oxcarbazepine is reported. An 8 year old boy with partial seizures developed maculopapular rashes with itching on day 15 of carbamazepine therapy. After stopping carbamazepine, phenytoin 100 mg daily was prescribed two days later. On the 12th day of phenytoin therapy he developed cervical and axillary lymphadenopathy with fever. Lymph nodes revealed reactive hyperplasia. Oxcarbazepine 75 mg twice daily also resulted in oral and mucosa ulceration. The seizures were controlled without any side effects with sodium valproate 200 mg three times a day and gabapentin 300 mg twice a day. Due to the cross reactivity of aromatic anticonvulsants (phenytoin, carbamazepine, and oxcarbazepine), valproate or newer anticonvulsants should be used if a patient has sensitivity to these drugs.
Topics: Anticonvulsants; Carbamazepine; Child; Drug Eruptions; Drug Interactions; Humans; Male; Oral Ulcer; Oxcarbazepine; Phenytoin; Seizures
PubMed: 14707249
DOI: No ID Found -
American Journal of Veterinary Research Apr 2001To determine pharmacokinetics and excretion of phenytoin in horses.
OBJECTIVE
To determine pharmacokinetics and excretion of phenytoin in horses.
ANIMALS
6 adult horses.
PROCEDURE
Using a crossover design, phenytoin was administered (8.8 mg/kg of body weight, IV and PO) to 6 horses to determine bioavailability (F). Phenytoin also was administered orally twice daily for 5 days to those same 6 horses to determine steady-state concentrations and excretion patterns. Blood and urine samples were collected for analysis.
RESULTS
Mean (+/- SD) elimination half-life following a single IV or PO administration was 12.6+/-2.8 and 13.9+/-6.3 hours, respectively, and was 11.2+/-4.0 hours following twice-daily administration for 5 days. Values for F ranged from 14.5 to 84.7%. Mean peak plasma concentration (Cmax) following single oral administration was 1.8+/-0.68 microg/ml. Steady-state plasma concentrations following twice-daily administration for 5 days was 4.0+/-1.8 microg/ml. Of the 12.0+/-5.4% of the drug excreted during the 36-hour collection period, 0.78+/-0.39% was the parent drug phenytoin, and 11.2+/-5.3% was 5-(phydroxyphenyl)-5-phenylhydantoin (p-HPPH). Following twice-daily administration for 5 days, phenytoin was quantified in plasma and urine for up to 72 and 96 hours, respectively, and p-HPPH was quantified in urine for up to 144 hours after administration. This excretion pattern was not consistent in all horses.
CONCLUSIONS AND CLINICAL RELEVANCE
Variability in F, terminal elimination-phase half-life, and Cmax following single or multiple oral administration of phenytoin was considerable. This variability makes it difficult to predict plasma concentrations in horses after phenytoin administration.
Topics: Administration, Oral; Animals; Anticonvulsants; Area Under Curve; Biological Availability; Cross-Over Studies; Female; Half-Life; Horses; Injections, Intravenous; Phenytoin; Random Allocation; Statistics, Nonparametric
PubMed: 11327452
DOI: 10.2460/ajvr.2001.62.483 -
Epilepsia 1999This article describes a flexible, dynamic system for comparing antiepileptic drugs (AEDs) as monotherapy, taking into account the needs of the patient and the... (Review)
Review
This article describes a flexible, dynamic system for comparing antiepileptic drugs (AEDs) as monotherapy, taking into account the needs of the patient and the characteristics of the treatment. Because differences in efficacy between AEDs cannot readily be demonstrated in regulatory clinical trials, safety is of paramount importance. Each drug has been judged across 11 criteria. These include knowledge of mechanism of action, suitable pharmacokinetics, drug interactions, delineated range of efficacy, ease of titration, idiosyncratic reactions, sedative burden, neuropsychiatric profile, teratogenic potential, and the likelihood of producing long-term side effects. The final consideration relates to how "comfortable" the doctor is with prescribing the drug as monotherapy. Scores of -1 (drawback), 0 (neutral/unknown), or +1 (advantage) have been allocated under each category, depending on current knowledge and clinical experience. The sum of the individual scores determines the awarding of "stars." In addition, the positive and negative features of each AED, when used as monotherapy, are highlighted. A range of established and new AEDs has been examined using the "monostars" method, including phenobarbital, phenytoin, carbamazepine, sodium valproate, lamotrigine, gabapentin, oxcarbazepine, and vigabatrin. Scores can be adjusted as new information comes to light. Other agents can be added when suitable monotherapy data become available. This analysis supports the contention that choice of treatment in newly diagnosed epilepsy should take into consideration the patient's age, sex, general health, coexisting disabilities, concomitant medication, and life style. Seizure type, syndrome, and the AED's pharmacology, efficacy, and safety profile should also be considered. Because dosing is often modest, cost should rarely be the overriding factor in choosing a drug for a patient with newly diagnosed epilepsy in the developed world. With these criteria, some of the newer AEDs have potentially more to offer the patient as monotherapy than do the established agents.
Topics: Acetates; Amines; Anticonvulsants; Carbamazepine; Cyclohexanecarboxylic Acids; Drug Administration Schedule; Epilepsy; Gabapentin; Humans; Lamotrigine; Oxcarbazepine; Phenobarbital; Phenytoin; Practice Guidelines as Topic; Practice Patterns, Physicians'; Triazines; Valproic Acid; Vigabatrin; gamma-Aminobutyric Acid
PubMed: 10530678
DOI: 10.1111/j.1528-1157.1999.tb00928.x