Biomaterial Database

Phenytoin and carbamazepine: differential effects on cognitive function. 1995

A P Aldenkamp, and J Vermeulen

Department of Neuropsychology, Meer & Bosch Epilepsy Centre, Heemstede, The Netherlands.

This review summarizes the studies on the cognitive side-effects of two important antiepileptic drugs: phenytoin and carbamazepine. A large literature database was compiled through the DIMDI computer database and the inspection of recent reviews. Only scientific articles published in peer-reviewed journals during the last 25 years were selected. Of the 358 potentially relevant papers on cognitive effects of AEDs, a total of 16 studies have been found that have studied both carbamazepine and phenytoin. After excluding studies with designs that do not permit valid inferences regarding the cognitive effects of AEDs, only five studies remained. The evaluation of these studies reveal that our current knowledge allows us to draw conclusions about the cognitive side-effects of phenytoin and carbamazepine only with great caution. The claim in reviews that 'both drugs have an impact on cognitive function, PHT to a larger degree than CBZ' is simply not supported by valid 'high quality' data. The same is true for the overall conclusion in more recent reviews that 'drug-induced cognitive effects of these AEDs on cognitive function are probably mild or even negligible'. Apparently, the only information that we have is that the differential impact of PHT and CBZ on cognitive function is not extremely different. No conclusive and reconfirmed data are available on the absolute effects of CBZ and PHT (differences between the two drugs and a no-treatment condition). Our review summarizes some recommendations for future studies.

UI	MeSH Term	Description	Entries
D009483	Neuropsychological Tests	Tests designed to assess neurological function associated with certain behaviors. They are used in diagnosing brain dysfunction or damage and central nervous system disorders or injury.	Aphasia Tests,Cognitive Test,Cognitive Testing,Cognitive Tests,Memory for Designs Test,Neuropsychological Testing,AX-CPT,Behavioral Assessment of Dysexecutive Syndrome,CANTAB,Cambridge Neuropsychological Test Automated Battery,Clock Test,Cognitive Function Scanner,Continuous Performance Task,Controlled Oral Word Association Test,Delis-Kaplan Executive Function System,Developmental Neuropsychological Assessment,Hooper Visual Organization Test,NEPSY,Neuropsychologic Tests,Neuropsychological Test,Paced Auditory Serial Addition Test,Repeatable Battery for the Assessment of Neuropsychological Status,Rey-Osterrieth Complex Figure,Symbol Digit Modalities Test,Test of Everyday Attention,Test, Neuropsychological,Tests, Neuropsychological,Tower of London Test,Neuropsychologic Test,Test, Cognitive,Testing, Cognitive,Testing, Neuropsychological,Tests, Cognitive
D010672	Phenytoin	An anticonvulsant that is used to treat a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.	Diphenylhydantoin,Fenitoin,Phenhydan,5,5-Diphenylhydantoin,5,5-diphenylimidazolidine-2,4-dione,Antisacer,Difenin,Dihydan,Dilantin,Epamin,Epanutin,Hydantol,Phenytoin Sodium,Sodium Diphenylhydantoinate,Diphenylhydantoinate, Sodium
D002220	Carbamazepine	A dibenzazepine that acts as a sodium channel blocker. It is used as an anticonvulsant for the treatment of grand mal and psychomotor or focal SEIZURES. It may also be used in the management of BIPOLAR DISORDER, and has analgesic properties.	Amizepine,Carbamazepine Acetate,Carbamazepine Anhydrous,Carbamazepine Dihydrate,Carbamazepine Hydrochloride,Carbamazepine L-Tartrate (4:1),Carbamazepine Phosphate,Carbamazepine Sulfate (2:1),Carbazepin,Epitol,Finlepsin,Neurotol,Tegretol
D002986	Clinical Trials as Topic	Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.	Clinical Trial as Topic
D003071	Cognition	Intellectual or mental process whereby an organism obtains knowledge.	Cognitive Function,Cognitions,Cognitive Functions,Function, Cognitive,Functions, Cognitive
D004359	Drug Therapy, Combination	Therapy with two or more separate preparations given for a combined effect.	Combination Chemotherapy,Polychemotherapy,Chemotherapy, Combination,Combination Drug Therapy,Drug Polytherapy,Therapy, Combination Drug,Chemotherapies, Combination,Combination Chemotherapies,Combination Drug Therapies,Drug Polytherapies,Drug Therapies, Combination,Polychemotherapies,Polytherapies, Drug,Polytherapy, Drug,Therapies, Combination Drug
D004827	Epilepsy	A disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. Epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (From Adams et al., Principles of Neurology, 6th ed, p313)	Aura,Awakening Epilepsy,Seizure Disorder,Epilepsy, Cryptogenic,Auras,Cryptogenic Epilepsies,Cryptogenic Epilepsy,Epilepsies,Epilepsies, Cryptogenic,Epilepsy, Awakening,Seizure Disorders
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012307	Risk Factors	An aspect of personal behavior or lifestyle, environmental exposure, inborn or inherited characteristic, which, based on epidemiological evidence, is known to be associated with a health-related condition considered important to prevent.	Health Correlates,Risk Factor Scores,Risk Scores,Social Risk Factors,Population at Risk,Populations at Risk,Correlates, Health,Factor, Risk,Factor, Social Risk,Factors, Social Risk,Risk Factor,Risk Factor Score,Risk Factor, Social,Risk Factors, Social,Risk Score,Score, Risk,Score, Risk Factor,Social Risk Factor