Acetphenetidin (C10H13NO2 = 177.79) is produced by the action of glacial acetic acid on para-amidophenetidol. Being the least dangerous, it is selected as a type of the aniline analgesic antipyretics.
Central Nervous System. - Acetphenetidin is assumed to block the sensations of pain, in the region of the thalamus. It also increases spinal irritability, and acts on some parts of the medulla.
Muscular System. - No action.
Respiration. - Slightly increased from centric action.
Heart. - First accelerated, then slowed, by direct action on the heart muscle.
Blood-pressure responds in balance to heart action.
Blood is altered by the formation of methemoglobin, varying directly with the size of the dose.
Alimentary Tract. - Somewhat irritated.
Secretory Glands. - Sweat-glands are sometimes greatly stimulated.
Metabolism. - Possibly some increase in nitrogen elimination.
Temperature is rapidly reduced through centric action. The temperature-equilibrium point being thus lowered induces heat dissipation through the cutaneous vessels. (Febrile cases, only.)
Absorption is rapid.
Excretion takes place rapidly through the urine as para-amidophenol and its compounds.
Local Action. - Thought to have some local analgesic effect.
Tolerance is sometimes acquired, with ultimate chronic poisoning and mental debility.
Therapeutic Doses. Sedative effect on brain. Relief from migraine. Depression of sensory side of cord. Slight slowing of pulse. Fall of temperature in fever.
Large Doses. Perspiration. Somnolence. Cyanosis.
Rapid pulse becoming very slow. Rapid breathing becoming very slow. Collapse.
Susceptible patients will react with the symptoms cited under "large doses" even when the dose is very small.
The use of the coal-tar derivatives for combating fever is questionable, especially when non-toxic measures, like cool sponging, give amply good results. But in migraines and neuralgias, acetphenetidin may be used advantageously, due caution being exercised as to the possibility of toxicity.
Acetphenetidinum, 0.3 to 0.6 Gm.
Green = irritation. Violet = depression.