title: Serum theophylline and phenytoin levels: can we afford to do them? Can we afford not to?
abstract: The following factors must be considered when determining the need for theophylline and diphenylhydantoin (DPH) levels: accuracy and reproducibility, turnaround time, and cost-benefit ratio for the patient. Serum levels must bear a relationship to the therapeutic effects of the drugs. In addition, the pharmacology of the drugs must be of such an order of complexity that there is not a simple relationship between dosage and serum levels.
mesh_terms: D000042:Absorption; D000293:Adolescent; D000328:Adult; D001711:Biotransformation; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D003955:Diagnostic Tests, Routine / Q000191:economics; D004630:Emergencies; D006801:Humans; D007223:Infant; D007700:Kinetics; D008875:Middle Aged; D010672:Phenytoin / Q000009:adverse effects / Q000097:blood* / Q000378:metabolism; D013806:Theophylline / Q000009:adverse effects / Q000097:blood* / Q000378:metabolism
chemical_list: D010672:Phenytoin; D013806:Theophylline