Sodium salts have not the depressant effect so marked in those of potassium.
In medicine copper sulphate was employed as an emetic, but its employment for this purpose is now very rare, as it is exceedingly depressant, and if it fails to act, may seriously damage the gastric mucous membrane.
Emetine acts as a gradual depressant to the nervous system in animals.
This is accelerated by a marked depressant action upon the heart, similar to that produced by veratrine and aconite.
But on account of this depressant action it is to be avoided for women and children and rarely used for men.
Potassium nitrate was used at one time in many different diseased conditions, but it is now never administered internally, as its extremely depressant action upon the heart is not compensated for by any useful properties which are not possessed by many other drugs.
In medicine antipyrine ("phenazonum") has been used as an analgesic and antipyretic. The dose is 5-20 grs., but on account of its depressant action on the heart, and the toxic effects to which it occasionally gives rise, it is now but little used.
Digitonin, on the other hand, is a cardiac depressant, and has been found to be identical with saponin, the chief constituent of senega root.
It is a powerful cardiac depressant, diminishing both the force and frequency of the heart's beat.
In large doses it has a depressant action on the nervous system, leading even to coma and total abolition of reflex action.
The treatment is to empty the stomach by tube or by a non-depressant emetic. The physiological antidotes are atropine and digitalin or strophanthin, which should be injected subcutaneously in maximal doses.
Similarly the depressant action on the respiratory centre in the medulla oblongata occurs only after the administration of enormous doses.