The root of Piper methysticum, Forster (Nat. Ord. Piperaceae). South Sea Islands. Dose, 5 to 60 grains.
Common Names: Kava-Kava, Ava, Ava-Pepper Shrub, Intoxicating Long Pepper.
Principal Constituents.—Starch (50 per cent), methysticin (C15H14O5), the methyl ester of methysticic acid; kavahin (methylene protocatechuic aldehyde, identical with heliotropin or piperonal); and the chief active principle, an acrid resin (2 per cent) separable into the local anesthetic alpha-resin and the less active beta-resin.
Preparation.—Specific Medicine Piper Methysticum. Dose, 5 to 60 drops.
Specific Indications.—Irritation, inflammation, or debility of the urinary passages; chronic catarrhal inflammations; vesical irritation and inflammation; vesical atony; painful micturition, strangury, and dysuria; gonorrhea, slow and intractable; gleet; anorexia; gastric atony; pale and edematous tissues, with scanty or irregular flow of urine, and indisposition to exertion; dizziness and despondency; neuralgia, idiopathic or reflex.
Action.—Piper Methysticum stimulates the salivary but not the cutaneous glands, and strongly excites the kidneys to watery diuresis, proportionately less solid material being voided in the urine. Upon the stomach it acts much like the stimulant bitters, increasing the appetite, and produces neither diarrhea nor dysentery. The central nervous system is stimulated by it to a species of intoxication, somewhat resembling but differing, however, from that caused by ethylic inebriation. Large doses will cause a drowsy and reserved intoxication, with confused dreams. The taste being agreeable, it is said one easily becomes a proselyte to its seductive qualities. The intoxicating drink prepared from it by the natives of certain Pacific islands induces an intoxication of a reserved drowsy character attended with confused dreams. Its long-continued use by them has caused more or less obscuration of vision and a dry, cracked, scaly and ulcerated skin, and lesions closely allied to leprosy.
Therapy.—Piper methysticum, "the intoxicating long pepper", is not an old medicine, though under the name of kava-kava and closely similar appellations it has been used in the preparation of a disgusting ceremonial drink among certain South Sea Islanders from early times. As a medicine it has the fourfold quality of being stimulant, sialagogue, tonic, and anaesthetic. Its field of action is upon the sensory nerves and mucous tracts of the body, more especially those of the genito-urinal and gastro-intestinal tubes.
Piper methysticum is an appetizer and tonic to the gastro-intestinal organs, this influence being especially marked when associated with urinary disorders. The patient is pale, the urinary product inconstant in quality; the tissues, especially of feet and legs, are edematous patient is indisposed to exertion, and has the general appearance of one with Bright's disease, yet there is no albumen nor evidence of any particular disease. Such symptoms clear up quickly under this remedy, and the appetite is quickly restored. Piper methysticum augments digestion and promotes better assimilation. The glandular activity of the digestive tract is increased, natural secretion and excretion favored, constipation is overcome, and hemorrhoids, if present, are reduced. It also exerts a marked curative influence in chronic intestinal catarrh.
The best known remedial action of this drug is upon the genito-urinal tract, in which, through presumably decreasing the blood supply by contracting the capillaries, it allays irritation with its consequent pain in urination, difficult micturition, and inflammation with discharges of mucus or muco-pus. Its reputation as a blennostatic in gonorrhea is well sustained, but, as with all remedies, the specific condition must be present for its best results. It relieves in that form of acute gonorrhea which is sluggish, tardy in responding to treatment, and tending toward the establishment of gleet. It is also a good agent in gleet. In the more acute cases it favorably assists the action of gelsemium, belladonna, and macrotys; while if there is marked debility it may be given with nux vomica or strychnine. Piper methysticum increases the power to urinate and, through its anaesthetic qualities, alleviates pain in the bladder and urethra, hence its value in debilitated and irritated conditions of those organs. It thus becomes an effective remedy sometimes in dysuria, painful micturition, strangury, chronic inflammation of the neck of the bladder, acute urethritis, nocturnal enuresis of old and young when due to muscular atony, and old feeble cases of catarrh of the bladder. It is also of some value in acute vaginitis, chronic bronchitis, rheumatism, and dropsy due to renal inefficiency.
Piper methysticum is a remedy for neuralgic pain, especially of the branches of the 5th nerve. It sometimes relieves ocular and aural neuralgia, toothache when not due to dental caries, neuralgia of the stomach and intestines, and neuralgic and spasmodic dysmenorrhea. Such reflex neuralgias as abdominal neuroses due to prostatic, urethral, or testicular diseases, or pectoral neuralgia arising reflexly from nervous dyspepsia are cases for the exhibition of Piper methysticum.