Camphor (C10H16O = 150.98) is a stearopten derived from Cinnamomum Camphora, a tree of Japan, China, Formosa, and Eastern Africa.

Pharmacodynamics.

Central Nervous System. - Camphor produces a descending depression, possibly preceded in man by cerebral stimulation.

Muscular system not affected directly.

Respiration. - Slightly slower and deeper from centric action.

Heart. - Sometimes slightly slower; centric action.

Blood-pressure. - Slight fall, due to vasodilator action.

Alimentary tract is mildly irritated.

Secretory Glands. - Mildly stimulating.

Metabolism. - Camphor indirectly stimulates the leucocytes.

Temperature is lowered in fever; mode of action is uncertain.

Absorption is rapid from the stomach.

Excretion. - Camphor is oxidized in the tissues and eliminated in the urine in a combination with glycuronic acid.

Local Action. - Camphor is slightly irritant to nerves of sensation and pain.

Symptoms.

Medicinal Dose. Hot, bitter taste. Warm sensation in stomach. Feeling of comfort.

Large Doses. Headache, confusion. Excitement. Slowing of pulse. Nausea and vomiting. Flushing of skin. Hallucinations. Deliria. Stupor. Unconsciousness.

Toxic Doses. Drowsiness. Unconsciousness. Stupor. Respiratory failure.

Therapeutics.

Camphor was formerly much used as an antispasmodic and nerve sedative. Its principal use today is for counterirritation, giving best results when made up in strong (50%) alcoholic solutions. For tender skins a 10% solution in oil may be used.

Dosage.

Spiritus Camphorae (10%), 0.3 to 2 mils.