[Monitoring therapy by analysis of the drug concentration of saliva].
The distribution of a drug between blood and saliva depends on its physicochemical properties, e.g. binding to plasma proteins, apparent dissociation constant and lipid solubility. The clinical value of measuring salivary drug concentrations in therapeutic drug monitoring is demonstrated using anticonvulsant therapy in children as an example. For carbamazepine and phenytoin there is a close and constant saliva/serum ratio over a wide range of concentrations, which is influenced by the salivary flow rate only to an insignificant degree. Salivary concentrations of carbamazepine account for about 40%, of phenytoin for about 10% of the serum concentrations. In contrast, salivary levels of primidone and phenobarbital are significantly influenced by the rate of saliva flow. In resting saliva primidone levels slightly exceed those in serum and fall significantly below the corresponding serum values during forced stimulation of salivary flow. For phenobarbital in resting saliva the mean saliva/serum ratio is 0.3 and increases significantly during forced stimulation. Provided the conditions of sample collection are standardized saliva is suitable for monitoring primidone and phenobarbital therapy, too.
D000927:Anticonvulsants / Q000032:analysis* / Q000378:metabolism; D002220:Carbamazepine / Q000032:analysis / Q000378:metabolism; D006801:Humans; D008991:Monitoring, Physiologic; D010634:Phenobarbital / Q000032:analysis / Q000097:blood; D010672:Phenytoin / Q000032:analysis / Q000378:metabolism; D011324:Primidone / Q000032:analysis / Q000378:metabolism; D012463:Saliva / Q000032:analysis*
D000927:Anticonvulsants; D011324:Primidone; D002220:Carbamazepine; D010672:Phenytoin; D010634:Phenobarbital
Therapieüberwachung durch Bestimmung von Pharmakakonzentrationen im Speichel.