Saliva and Serum Lithium Monitoring in Hospitalized Patients and Possibility to Replace Serum to Saliva

Abstract

The lithium ions concentration in human serum and saliva was determined using dry-slide technology Vitros 250 Analyser (Ortho Clinical Diagnostic) and atomic absorption spectrometry Perkin Elmer 403 (AAS). We analyzed lithium ions in 100 serum and saliva specimens of patients after oral administration of lithium carbonate (3 x 300 mg) Jadran, Galen Laboratory Rijeka. Saliva and blood were taken 2 and 12 hours after the last dose. At the same time lithium ions at samples of blood and saliva were determined with both methods which showed high level of correlation. The mean difference of lithium ions between saliva and serum was statistically significant for p<0.05 using t student test. At saliva we got constant of elimination Kel = 0.02(-1)h and elimination half life (t(1/2)) was t(1/2)=34.6 h. For serum was t(1/2)= 24 h what means that lithium ions elimination is slower from saliva then from serum. That is the reason why probably concentration at saliva is higher then at serum. Lithium elimination is two compartment pharmacokinetic model where important part of compartment are saliva and salivary glands. At a certain point in medical treatment it could be expected to use controlled determination of lithium ions in saliva with serum as control.

Saliva testing as a means to monitor therapeutic lithium levels in patients with psychiatric disorders: identification of clinical and environmental covariates, and their incorporation into a prediction model

“…While we found no association between time lapsed from last dose to blood collection, and either salivary lithium, serum lithium or saliva/serum lithium ratios, previous research by Serdarevic et al which compared salivary lithium and serum lithium correlations at 2-and 12-hours post-last dose, suggested that the saliva-serum correlation may be improved by collecting samples closer to the last dose [32] . Also, because of the known difference in lithium pharmacokinetics in saliva vs. serum [32,41] , the timing of the last dose is of critical importance. For inpatients, saliva measures could also be used to better optimize the timing of trough levels, as saliva sampling would not be restricted to a phlebotomist's schedule.…”

“…Considering the overall literature, despite variations in methods of salivary lithium collection and quantification, the majority of previous studies have reported saliva/serum lithium correlations similar to that observed in our study [28][29][30][31][32][33] . This consistency in results across studies, as well as the stability in saliva/serum lithium ratios in most patients across time observed in our study, opens the door for the development and implementation of a point-of-care (POC) salivary lithium device.…”

“…In fact, a large body of work dating back >30 years has suggested that salivary lithium might be useful for patient monitoring of lithium levels, with several previous studies demonstrating good correlation between saliva and serum lithium values (i.e. between 0.50 to 0.88) [16,[28][29][30][31][32][33] . However, in past studies, the sample sizes were small, saliva collection techniques varied, older methods for lithium quantification were used and medical and lifestyle variables were not included [16] .…”

Rapid and in situ optical detection of trace lithium in tissues

“…10(b-f) ). Clinically, lithium ions have been detected in the saliva of patients treated with lithium [ 27 ].…”

Lithium chloride could aggravate brain injury caused by 3-nitropropionic acid

“…Lithium is known to have narrow therapeutic range in the serum [28][29][30]. In a high dose, it could also be neurotoxic.…”