The prevention and cure of tetany by oral administration of magnesium lactate.

Abstract

It was demonstrated in a recent series of experiments 1 that strontium lactate administered orally to parathyroidectomized dogs greatly delays the onset of tetany, and may even bring about a permanent cure if the treatment is long continued. Preliminary experiments, carried out in conjunction with the strontium work, indicated that magnesium salts act similarly to strontium. The present paper is concerned with this phase of the work.

If parathyroidectomized dogs are given a 5 per cent solution of magnesium lactate in 100 cc. doses three times daily by stomach tube, they may be kept free from tetany for long periods, occasionally for three weeks. Some of the animals may develop tetany after eight or ten days. Once tetany becomes manifest, and the serum calcium falls below 7 mg. per 100 cc., the magnesium exerts little effect except to allay the more violent symptoms, probably through its anesthetic effect. However, if the animal is fed a pint or more of milk each day, along with the magnesium, the tetany soon disappears, generally within three or four days, and if the milk is discontinued the dog remains normal and shows no tetany symptoms so long as the magnesium is administered. Examination of the serum calcium shows that the calcium has risen to 7.5 or 8 mg. per 100 cc., which is above the level at which tetany becomes manifest in dogs.

The experiments indicate clearly that magnesium, per se, exerts little influence on tetany except through its action in sparing calcium. Somehow, the magnesium prevents the serum calcium from falling below the tetany level. A striking illustration of the sparing action of magnesium on calcium is shown in the following experiment. Parathyroidectomized dogs were allowed to develop tetany and then given the regular magnesium treatment.