A comparative double-blind study of the side effects of Litarex and Lithionit Durettes.

Side effects of two lithium salts of the sustained-release type were compared in a cross-over double-blind study. Eighteen patients with uni- or bipolar type of manic-depressive diseases were included in the trial. The drugs compared were lithium citrate (Litarex, Dumex Ltd.) and lithium sulphate (Lithionit Durettes, Hässle Ltd.). After the patients had been adjusted to a serum concentration of 0.8-1.2 mmol/l, self-assessment of the frequency and intensity of 16 side-effect variables was performed during a period of 4 weeks. The most common side effects were tremor, fatigue, polyuria, polydipsia, and reduced power of concentration. There was no difference in the frequency or intensity of the side effects between the two drugs. The side effects are, accordingly, considered an effect of the lithium ion, rather than of the lithium salt. The difference in the size and appearance of the tablets was of very little practical significance.