AIM To investigate the effect of
collection methods and
diurnal rhythm on the carbamazepine (CBZ)level in saliva. METHODS
①The saliva samples were collected by three methods (Nature, Cotton ball and Citric acid) in turn from 12 epileptic patients with blood samples collected simultaneously. ② The Cotton Ball was used to collect 8 patients's saliva in 4 time points within 24 hours with blood samples collected simultaneously. The CBZ levels in saliva and serum were measured by HPLC; then compared the correlationship of them between saliva and serum statisticly. RESULTS The CBZ concentrations in saliva gathered by different methods were 2.81 mg·L -1 (Nature), 2.06 mg·L -1 (Cotton ball) and 2.22 mg·L -1 (Citric acid); the correlation coefficients (r) between saliva and plasma was 0.853, 0.904, 0.906 respectively. Multi time points detection result showed that the concentration of CBZ was changed in one day, the saliva: plasma concentration ratios (S/P) at 7:00, 11:00, 15:00, 21:00 were 0.335, 0.321, 0.309 and 0.358. The correlation coefficients (r) were 0.85, 0.93, 0.92 and 0.98. CONCLUSION The methods of Cotton ball and Citric acid is better than Nature, the CBZ concentration in saliva is influenced by the
diurnal rhythm; 11:00, 15:00 and 21:00 is the best time points for saliva collection.