Botanical name: 

Related entry: Cinnamomum saigonicum/zeylanicum

A stearopten (having the nature of a ketone) derived from Cinnamomum Camphora (Linné), Nees et Ebermeier (Nat. Ord. Lauraceae). China and Japan.
Common Names: Camphor, Laurel Camphor, Gum Camphor (it is not a gum).

Description.—Tough, translucent white lumps or granules, having the pungent taste known as camphoraceous, and an aromatic penetrating odor. It dissolves freely in alcohol, chloroform, ether, and fixed and volatile oils; very slightly in water. Camphor is readily pulverized by triturating it with a few drops of alcohol, chloroform, or ether. Dose (by mouth), 1 to 5 grains; (hypodermatically) 1 to 3 grains.
Preparations.—1. Spiritus Camphorae (10 per cent), Spirit of Camphor. Dose, 1 to 30 drops.
2. Aqua Camphorae. Camphor Water. Dose, 1 to 4 fluidrachms.
3. Linimentum Camphorae. Camphor Liniment (Camphorated Oil) (Composed Of Camphor, 200 parts; Cottonseed Oil, 800 parts). Dose, 10 to 30 drops. For external use chiefly.
4. Ceratum Camphorae. Camphor Cerate. (Composed of Camphor Liniment, White Wax, White Petrolatum, and Benzoinated Lard.) For external use.

Action.—Camphor causes a local dilation of the capillaries of the skin, producing warmth, redness, and sometimes itching. Slight anesthesia follows. It causes smarting and hyperaemia of the mucosa, and if applied strong may cause considerable irritation. In this manner it has produced gastric ulceration. In small doses camphor warms the stomach, stimulates secretion, increases peristalsis, and expels flatus. Large doses may induce vomiting. Camphor is readily absorbed, both from application and inhalation. It is largely changed in the body and is eliminated in the urine as campho-glycuronic acid. In moderate doses camphor directly stimulates the heart-muscle, causing slower and stronger contractions and increased arterial pressure, but after large doses the pressure falls. Respiration is slightly stimulated by it, large doses causing slower and deeper breathing. In general it may be said that small doses of camphor stimulate, while large quantities depress, or even paralyze. This is true of all the functions it affects. The action of small doses upon the nervous system is to produce a feeling of slight exhilaration or contentment. Large doses excite the higher cerebral and medullary centers and then paralyze them; poisonous doses occasioning more or less of the following symptoms: esophageal and gastric pain, vomiting, headache, dizziness, mental confusion, drowsiness, delirium, and stupor; feeble, running, or intermittent pulse, cold skin, cold sweat, and muscular weakness followed by rigidity and epileptiform. convulsions, collapse and death. The type of convulsions shows its effects to be chiefly upon the cerebral cortex, though it acts also progressively on the medulla, causing death by respiratory paralysis. Camphor does not affect all persons alike. Some may pass directly into drowsiness, insensibility, and stupor, followed by death. If taken for long periods, even in moderate doses, camphor gives rise to a state of mental confusion. Opium and repeated small doses of alcohol are the best antagonists of the untoward effects of camphor.

Therapy.—External. Camphor is stimulant, rubefacient, antipruritic, and feebly antiseptic. Owing to its agreeable odor and pleasant stimulating effects it is largely used, as a powder, in lotions, and ointments, or rubbed up with other solids to produce anodyne and antiseptic liquids. In this manner, when triturated with chloral hydrate, menthol, phenol, thymol, and similar bodies, ideal liquid antiseptics are obtained for use upon wounds, neuralgic and other painful areas.

Powdered camphor is an ingredient of tooth powders and pastes and dusting powders for skin diseases. Alone or with zinc oxide, talc, or precipitated chalk it may be used upon bed-sores with decided relief. Such combinations are valuable in intertrigo, chronic eczema, urticaria, and zoster. Many snuffs contain powdered camphor, and it is useful to stimulate sluggish ulcers. Sprinkled upon the face it is used to control itching and to prevent pitting in small-pox. The spirit is a household embrocation for the relief of pain and itching, and it is used largely, alone, or in liniments and embrocations, for the relief of pain, stiffness, soreness and swelling, as in myalgia, facial and other neuralgias, and upon rheumatic joints, deep inflammations, chronic indurated glands and other indurations, sprains, contusions, and inflammatory swellings. An ethereal tincture of camphor is said to give relief in erysipelas. Inhaling the spirit, or camphor dropped into hot water, gives relief in nervous headache, and often aborts acute colds, coryza, and influenza, giving respite from the excessive secretion and the accompanying headache. A solution of camphor in liquid petrolatum (usually with menthol) is a popular spray for similar uses, and for laryngitis, pharyngitis, chronic nasal catarrh and hypertrophic rhinitis. The spirit, the liniment, or camphorated oil are favorite applications for tenderness and pain, chilblains, toothache, and acute mastitis: in the latter it tends to suppress the milk. The spirit is in common use as a lotion for headache in nervous individuals with feeble circulation, and tendency to fainting. The oil, by injection, is sometimes effectual in removing seatworms. So-called "camphor-ice" is a soothing, camphorated petrolatum preparation for labial herpes.

Internal. Camphor is used to allay nervous excitement, subdue pain, arrest spasm, and sometimes to induce sleep. It is an important remedy in many disorders of neurotic women and children, being frequently most effective as a nerve sedative, antispasmodic, and carminative in nervous nausea and vomiting, flatulence, hiccough, and tendency to spasms or fainting. It is especially serviceable in palpitation of the heart due to gaseous distention of the stomach, or to nervous irritability. In occipital headache, from mental strain, or overstudy, small doses of camphor, together with the consentaneous use of it locally, frequently give prompt relief.

Camphor taken and inhaled may abort "cold in the head," or alleviate it when established. It checks the sneezing, copious, watery secretions and lachrymation and relieves the nasal and frontal headache. It similarly benefits in the acute coryza of epidemic influenza, or la grippe. As an ingredient of cough mixtures, such as camphorated tincture of opium, it contributes much toward relieving irritation, pain, oversecretion, and the associated nervous unrest. In very small doses it is useful in the bronchitis of the aged, while it helps greatly when depression attends slowly resolving cases of acute capillary bronchitis.

The most important use for camphor is in adynamic depression attending or following exhausting diseases. In typhoid, typhus, and other low forms of fevers and low grades of inflammation, with a quick irritable pulse, great restlessness, tremor, morbid watchfulness, dry skin, low muttering delirium and subsultus tendinum, it is one of the most active stimulating sedatives in the materia medica. Similar conditions sometimes occur in acute infectious diseases, as the exanthemata, in acute endocarditis and particularly in acute lobar pneumonia. For this profound depression 15 drops of a 10 per cent sterile oil or ether solution (both are sold in sealed ampoules) may be used hypodermatically and repeated as needed. The latter is similarly employed in shock and threatened collapse attending surgical operations.

In addition to the above-named preparations, solutions of camphor in alcohol, as well as a thirty per cent camphorated sesame oil, have been used in shock and collapse, and in lobar pneumonia. Indifferent results attend their use in many instances. In fatal cases, where such stimulation has been attempted, the death throes of the patient seem often to be aggravated. It is a common observation that patients to whom "camphor in oil" has been given, "die hard."

Camphor is largely used, usually with other pain-relieving agents, or with aromatic oils, as cajuput, in serous diarrhea, cholera morbus, and Asiatic cholera, in all when profoundly depressive. It is also useful (usually with opium, as in the diaphoretic powder, or with morphine, as in Tully powder) for spasmodic dysmenorrhea in nervous women, though the opiate content should not be oft repeated, nor long continued, nor given with the patient's knowledge of its use. Camphor frequently relieves menstrual headache, with great nervous depression. It is also useful to control irritation due to the passing of catheters and the strangury that sometimes results from the use of cantharidal blisters. King believed camphor an antidote to strychnine poisoning, supporting his views by the results he had observed on animals. In combination with bromides, camphor has given relief in the late stages of chordee.

Camphoric Acid, in doses of 15 to 40 grains, preferably in cachet or capsule, given a few hours before bedtime, is one of the most effective drugs for the colliquative night-sweats of phthisis.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.