This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Ava, Piper methysticum. The N. F. lists it as Kava, not Kava-Kava. Official in Great Britain. Possesses a diuretic action. The average system is stimulated, followed, when taken in large quantities, by a paralyzing action on some part of the motor tract. An intoxicating beverage is made from it in certain of the islands of the Pacific.
Large doses have no place in medicine. Small doses act as a tonic bitter, improving the appetite. Medium doses (fl. 10 to 30 minims, usually about 20 minims) are of value in gleet, chronic gonorrhea, and obstinate cystitis.
A rather agreeable remedy which does not derange digestion, and a resinous diuretic, kava-kava possesses points of merit. I have employed it in a great many genito-urinary cases and have found it to benefit many of them. The despondent and sensitive genito-urinary case who has been the rounds and ruined his stomach with all sorts of irritating drugs will often get along very comfortably on kava-kava. It is not a particularly potent drug, but it often serves a useful purpose.