In the review article, the authors, on the basis of literary data provided in Scopus, Google Scholar, and other publishers, provide information on the physicochemical, biochemical, pharmacological, and clinical properties of calcium and magnesium, emphasize their general pharmacodynamics, emphasize their differences, and reveal the stages, characteristic of hyper-and hypocalcemia and magnesiumemia. The stability of magnesium complexes with glucose and glucosamine is higher than with calcium. For coordination compounds of magnesium with glucose, the entropic contribution is greater, and for compounds of calcium with glucose -the enthalpic contribution. Calcium ions bind to proteins with greater activity than magnesium ions. The energy required for dehydrating magnesium 20Медицина is greater than for dehydrating calcium. Hypercalcemia and hypermagnesemia are observed less often than hypocalcemia and hypomagnesemia. The effect of calcium and magnesium drugs on the bone system, the effect on the cardiovascular and nervous systems, and the digestive tract is revealed. The peculiarity of the effect of calcium medicines. on the blood coagulation system is emphasized, they also have an anti-allergic effect. Calcium drugs affect all phases of blood coagulation. The antiallergic effect of calcium medicines is associated with stabilization of the cell membrane, inhibition of exudative reactions, influence on the hyaluronidase system with a change in vascular permeability. Magnesium-containing agents have a greater range of effects on cardiovascular and neurological drugs. Calcium drugs have a positive inotropic effect, increasing the strength of contractions of the myocardium and skeletal muscles. Calcium medicines can cause arrhythmias due to influx through calcium channels. Magnesium drugs have antiarrhythmic, antihypoxic and antiischemic effects. In the nervous system, calcium can play the role of a neurotransmitter. Magnesium medicines have a sedative, analgesic, antihypoxic, anticonvulsant effect. Magnesium is also considered a natural anti-stress factor. Magnesium deficiency can cause depression, cognitive impairment, and neurodegenerative diseases. There are calcium and magnesium monodrugs, as well as complex means. Calcium chloride, calcium gluconate, calcium glycerophosphate, calcium lactate are known among calcium medicines. From magnesium medicins, monodrugs are used -magnesium sulfate, magnesium oxide, magnesium hydroxide, as well as complex drugs -asparcam, rhythmocor, ATP-forte, magne B6.