Effect of Hypertension on Blood Lithium Level and its Concentration to Dose Ratio in Manic Episode Patients

The objective of this study was to further explore the influence of hypertension on blood lithium levels and its concentration to dose ratio (C/D) in patients with manic episodes. A total of 112 patients with manic episodes from the Wuhan Wudong Hospital between July 2021 and December 2022 were assigned into a control group (CG) and a hypertension group (HG). The patients’ blood lithium concentrations, blood lithium C/D ratios, antihypertensive medication use, Young Mania Rating Scale (YMRS) scores, adverse reactions (ARs), and other parameters were monitored and compared. The average blood lithium concentration in the CG was 0.78±0.27 mmol/L, and the average blood lithium C/D ratio was 0.91±0.43 mmol·L -1 ·g -1 ·d, which were remarkably inferior to those (0.89±0.20 mmol/L and 0.97±0.46 mmol·L - 1 ·g -1 ·d) in the HG. Further subgroup analysis based on antihypertensive medication revealed a drastic increase in blood lithium C/D ratio in the calcium channel blocker (CCB) subgroup. After the treatment, the YMRS score was 7.84±0.82 in the CG and 9.12±0.89 in the HG. The total number of ARs in the HG was superior to the CG, and the occurrence of ARs in both groups was concentrated within 3-15 days, accounting for 48.6% of all ARs. Patients in the HG had higher blood lithium concentrations, slower lithium metabolism, and a higher risk of ARs versus the CG. It was concluded that further investigation is warranted to explore the underlying mechanisms of these effects.