Origin. - Amido-acetparaphenetidin, a glycocoll derivative of phenetidin. The phenocoll hydrochloride is the salt used in medicine.

Description and Properties. - A white, crystalline powder, soluble in 16 parts of water, and freely soluble in hot alcohol, forming a neutral solution. Dose. - 3-15 grains (0.2-1.0 Gm.).

Incompatibles. - All the alkalies.

Physiological Action. - Phenocoll differs from phenacetine in no essential particulars.

Other phenetidine bodies are:

Lactophenin, in which a lactyl derivative is added to phenetidine. It is more soluble than phenacetine, and the lactyl group is supposed to add some hypnotic action.

Saliphenin is too weak to be of any service.

Citrophen and Apolysin are combinations of citric acid and phe-netidin. The citric acid radical was added for its stimulating effect on the heart, and hence these two are reputed to overcome the phenetidin-depressing effect on this viscus. The action, however, clinically, cannot be detected from that of phenacetin, and, moreover, there are certain objections, in the way of the splitting of these compounds in the stomach, which render them less suitable than phenacetine.

Salicylphenetidin was devised to combine the antirheumatic and antipyretic factors, but it appears that this compound is too stable and does not break up into its constituents, and is found in the urine in its original form.

Malakin is somewhat similar to the former drug. It breaks off a phenetidin, however, but is very slow of action and requires large doses to reduce the temperature.

Salocoll is similar to phenocoll plus salicylic acid.

Phesin and Cosaprin are new sulphur compounds of phenacetin and acetanilid, respectively, in which the sulphur radical is introduced to reduce the blood-toxic action. They offer no particular advantages.