The quantity of urine is generally increased under lithia, but analyses are not uniform as regards solid urinary products. Thus, M. Levy, using the bromide of lithia in gouty subjects, found the excretion of urea and uric acid rather lessened (Gazette Medicale de Paris, November 27, 1875). In healthy subjects, however, Moss found both liquid and solid constituents much increased (American Journal, April, 1861). Diuresis is usually a marked effect of lithia. One or two doses of 1 to 4 gr. may not. produce it, but if continued they do so, and commonly render soluble any urate deposit. In some persons one bottle of lithia water (about 4 gr.) will cause copious secretion, but the effect varies somewhat, possibly according to the amount of acid in the system. Dr. Garrod found lithia more active in this respect than potash, 20 to 30 gr. of the former citrate equalling 2 to 3 dr. of the latter. Moss corroborated this (loc. cit.).

Benzoate of lithia seems to have special powers in this respect, for it is very soluble, and the benzoic acid, changing in the system into hip-puric acid, combines with alkalies to form hippurates, which are more soluble and more readily eliminated than urates. The diuretic action of any salt of lithia is much increased by free dilution.

Synergists

Lithia is akin to potash, soda, and alkaline earths generally, but the characters of some of its salts indicate a special chemical analogy with magnesia. Thus, the carbonate is decomposed by heat, requires 100 parts of water for solution, but is more soluble in presence of carbonic acid: the phosphate is insoluble, the chloride and nitrate are deliquescent; there is no alum or bisulphate of lithia. Agents promoting waste, such as mercury and the iodides, also favor the constitutional action of this and allied medicines.

Antagonists And Incompatibles

Acids, acidulous and metallic salts.

Therapeutical Action (External)