Identifying patients who might benefit from free phenytoin monitoring
| Autor: | Buchanan N, M. Wall, Manglick Mp, Baird-Lambert J |
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| Rok vydání: | 1987 |
| Předmět: |
Drug
Phenytoin Male medicine.medical_specialty medicine.medical_treatment media_common.quotation_subject Serum albumin Pharmacology Binding Competitive Immunoenzyme Techniques Pharmacokinetics Internal medicine otorhinolaryngologic diseases medicine Humans heterocyclic compounds Pharmacology (medical) Child Serum Albumin media_common Aged Monitoring Physiologic Aspirin biology business.industry digestive oral and skin physiology Middle Aged nervous system diseases stomatognathic diseases Anticonvulsant Endocrinology Free fraction biology.protein Regression Analysis Female business Diazepam medicine.drug Protein Binding |
| Zdroj: | Therapeutic drug monitoring. 9(2) |
| ISSN: | 0163-4356 |
| Popis: | Guidelines for measuring free drug concentrations in serum have become necessary due to the easy availability of these assays as a result of the introduction of commercial kits. The present study was performed to identify patients or groups of patients in whom the serum free phenytoin fraction varied from normal, such that they might benefit from measurement of serum free phenytoin. Three hundred fourteen samples submitted for routine phenytoin analysis were studied by enzyme-modified immunoassay technique (EMIT). Thirty-eight patients on phenytoin monotherapy and without other factors thought to affect protein binding of this drug had a mean (PT SD) free phenytoin fraction of 9.8 ± 1.8% of total concentration (mean serum albumin concentration 43.4 ± 3.9 g/L). The free fraction was elevated by administration of comedications which are themselves highly protein bound, and in those patients who were hypoalbuminaemic (serum albumin 65 years, liver or renal disease, or pregnancy) did not, in themselves, produce a significant effect on free phenytoin fraction. Similarly, an elevated total serum phenytoin concentration was not a significant factor in producing an elevation in free phenytoin fraction. In most situations, total serum phenytoin measurement is adequate pharmacologically, but monitoring of free phenytoin levels may be useful in those patients with a low serum albumin and in those who take comedications that are themselves highly protein bound (e.g., sodium valproate, aspirin, or diazepam). |
| Databáze: | OpenAIRE |
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