Cathartics.

Cathartics are subdivided into Laxatives, Simple, Saline, Drastic, Hydragogue and Cholagogue Purgatives. (See ante, page 35.)

Laxatives.

Sulphur Lotum, Washed Sulphur. (See page 73.) Dose, ʒj-iij, as a laxative.

Manna,—the concrete exudation of Fraxinus Ornus. Dose, ʒj-℥ii. Contains Mannit, a sugar; also a Resin, probably the laxative principle.

Tamarindus, Tamarind,—the preserved pulp of the fruit of Tamarindus Indica. Used in Confectio Sennae. Dose, indefinite.

Magnesii Carbonas, Magnesium Carbonate,—Dose, ʒj-℥j. A mild laxative and antacid, but if long used it may form intestinal concretions.

• Mistura Magnesiae et Asafoetidae, Dewees' Carminative,—for flatulent colic and diarrhoea of infants,—Dose, gtt. xx-℥ss as per age. Has Mag. Carb. 5, Tinct. Asaf. 7, Tinct. Opii 1, Sugar 10, Water to 100.

Oleum Ricini, Castor Oil,—is a laxative in small doses,(ʒj), though classed with the simple purgatives. (See below). Also all the Simple Purgatives in minimum doses may be classed as laxatives.

Fruits of various kinds,—particularly Figs, Prunes, Stewed Apples, Raspberries and Strawberries,—many of which act through the mechanical stimulation of intestinal peristalsis by their small, indigestible seeds.

Simple Purgatives.

Senna,—the leaflets of Cassia acutifolia and Cassia angustifolia. Contains a glucoside, named Cathartic Acid, which is probably the active principle; also Sennacrol, Sennapicrin, bitter glucosides, and Catharto-mannit, a peculiar unfermentable sugar.

Extractum Sennae Fluidum,—Dose, ʒj-℥ss.

Syrupus Sennae, ʒj-℥j.

Confectio Sennae, Tamar-Indien, Tropical Fruit-Laxative, ʒj-iv.

Infusum Sennae Compositum, Black Draught,—℥j-iv. Contains in 100 parts, Senna 6, Manna 12, Magnesii Sulphas 12, Fennel 2.

Senna is a constituent also of the Pulvis Glycyrrhizae Compositus, of which it forms 18 per cent., with Liquorice, Oil of Fennel, Sulphur and Sugar, all triturated together. Dose, a teaspoonful.

Rheum, Rhubarb,—the root of Rheum officinale. Contains Phaeoretin, a purgative resin;—also Chrysophan, Rheo-tannic and Rheumic Acids, and the glucoside Erythroretin.

Extractum Rhei, gr. v-x.

Extr. Rhei Fl., ♏︎x-ʒj

Pilulae Rhei, j-iij.

Pilulae Rhei Compositae, ij-iv.

Aloë, Aloes,—the inspissated juice of the leaves of Aloë vera (Barbadoes Aloes), and Aloë Perryi (Socotrine Aloes). Contain Aloin, a neutral principle common to all varieties of the plant.

Aloinum, Aloin,—soluble in 60 of water. Dose, gr. ss-ij.

Aloë Purificata,—gr. j-v.

Pilulae Aloës,—pills j-v.

Pilulae Aloës et Asafoetidae,—ij-v.

Extr. Aloës,—gr. ss-vj.

Tinctura Aloës,—ʒs-ij.

Tinct. Aloës et Myrrhae,—ʒss-ij.

Oleum Ricini, Castor Oil,—a fixed oil expressed from the seeds of Ricinus communis,—Dose, ʒj-℥j. The purer it is the less purgative. It consists mainly of Ricinoleic Acid, combined with glycerin. Castor Oil is a constituent of Linimentum Sinapis Compositum, and Collodion Flexile.

Rhamnus Purshiana, Cascara Sagrada, (Chittem or Sacred Bark),—is the bark of Rhamnus Purshiana, the California Buckthorn, and contains several Resins, also a volatile oil, much tannin, etc.

Extractum Rhamni Purshianae Fluidum,—Dose, ʒss-ij.

*Cascara Cordial,—a trade preparation. Dose, ʒj-ii.

Frangula, Buckthorn,—is the bark, collected at least one year before being used, of Rhamnus Frangula, or Alder buckthorn, a European shrub (nat. ord. Rhamneae). It contains a cathartic glucoside named Frangulin, or Rhamnoxanthin, insoluble in water, and but sparingly so in alcohol or ether, and thought to be identical with the active principle of Senna.

Extractum Frangulae Fluidum,—Dose, ʒss-ij.

Saline Purgatives.

Magnesium Salts. The chief ones are the following,—

Magnesii Sulphas, Epsom Salt,—Dose, ʒj-℥j. Is very soluble in water.

Magnesii Citras Effervescens,—soluble in 2 of water. Dose, ʒj-℥j in plenty of water, drank while effervescing.

Potassium Salts. The principal ones are—

Potassii et Sodii Tartras, Rochelle Salt,—Dose, ℥ss-j. (See page 66.)

Pulvis Effervescens Compositus, Seidlitz Powder,—(See page 68.)

Potassii Bitartras, Potassium Bitartrate, (Cream of Tartar),—is sparingly soluble in water. Dose, ʒj-℥j as a purgative; gr. xx-ʒj as a diuretic. Is a constituent of Pulvis Jalapae Compositus (see below).

Potassii Sulphas, Potassium Sulphate,—Dose, gr. xx-℥ss, well diluted.

Sodium Salts. Those generally employed are as follows:—

Sodii Sulphas, Glauber's Salt,—Dose, ʒij-℥j. Soluble in water.

Sodii Phosphas, Sodium Phosphate,—Dose, ʒij-℥j, as a purgative; gr. xx-xl as an alterative. Has some pronounced cholagogue action, especially on children in 3 to 10-grain doses. Acts gently, and has little or no taste.

Drastic Purgatives.

Jalapa, Jalap,—the tuberous root of Ipomoea Jalapa, a Mexican plant of the nat. ord. Convolvulaceae. Contains 15 to 20 per cent. of the official Resin, which is composed of two resins, Jalapin and Convolvulin, the latter being the most active of the two.

Extractum Jalapae,—gr. ij-x.

Resina Jalapae,—gr. ij-x.

Pulvis Jalapae Compositus, (Pulvis Purgans),—has of Jalap 35, Potassium Bitartrate 65. Dose, gr. x-ʒi.

Scammonium, Scammony,—a resinous exudation from the root of Convolvulus Scammonia. Contains a Resin, which consists chiefly of Jalapin, the active principle, probably identical with the Convolvulin of Jalap.

Resina Scammonii, Resin of Scammony,—Dose, gr. iij-x. Is a constituent of the Compound Extract of Colocynth. (See below.)

Oleum Tiglii, Croton Oil,—a fixed oil expressed from the seeds of Croton Tiglium. Contains several fatty and volatile acids, one of which is called Tiglinic Acid. Dose, ♏︎⅓-ij, in pill of bread-crumb, emulsion or tincture.

Cambogia, Gamboge,—a gum-resin from Garcinia Hanburii, from Siam.

Pilulae Catharticae Compositae, Compound Cathartic Pills. (See under Colocynth, below.)

Colocynthis, Colocynth,—the fruit of Citrullus Colocynthis, the "bitter cucumber," a vine of the nat. ord. Cucurbitaceae, which also includes Ecballium Elaterium, Cucurbita Pepo, and Bryonia alba. (See below.) Colocynth contains an active, purgative glucoside, Colocynthin;—also Colocynthiline, which is soluble in ether, insoluble in water, and not purgative.

Extractum Colocynthidis,—Dose, gr. ½- ij. Not used alone.

Extractum Colocynthidis Compositum,—has of the Extract 16, Aloes 50, Cardamom 6, Resin of Scammony 14, Soap 14, and Alcohol 10 parts. Dose, gr. v-xx.

Pilulae Catharticae Compositae, Compound Cathartic Pills,—have of the preceding 8, Calomel 6, Ext. of Jalap 3, Gamboge 1 ½ , Water to make 100 pills. Dose, j-iij.

Elaterinum, Elaterin,—a neutral principle from Elaterium, a substance deposited by the juice of the fruit of Ecballium Elaterium, the "squirting cucumber," nat. ord. Cucurbitaceae. (See above.) Dose, gr. 1/30-1/10

Trituratio Elaterini, Trituration of Elaterin,—10 per cent., with Sugar of Milk. Dose, gr. ss-j.

Cholagogue Purgatives.

Podophyllum, May-apple,—the rhizome and rootlets of Podophyllum Peltatum, the Mandrake, (nat. ord. Berberideae). Its active principle is a Resin which is official, and is a compound of several resins. It probably contains also the alkaloid Berberine.

Extractum Podophylli,—gr. v-x.

Ext. Podophylli Fl.,—♏︎j-xxx.

Resina Podophylli, Podophyllin,—Dose, gr. ⅛-j in pill.

Leptandra, Culver's Root,—the rhizome and rootlets of Veronica virginica. Contains a Resin, and a glucoside, also Saponin, tannin, etc. The Leptandrin of the shops is an impure resin.

Extractum Leptandrae Fluidum,—Dose, ♏︎xx-ʒj.

Iris, Blue Flag,—the rhizome and roots of Iris versicolor. The Iridin of the shops is an impure oleo-resin precipitated from an alcoholic solution.

Extractum Iridis Fluidum,—Dose, ♏︎v-ʒj.

Extractum Iridis,—Dose, gr. j-v.

*Iridin,—Dose, gr. j-iij or v.

Hydrargyri Chloridum Mite, Calomel,—Dose, gr. j-x. (See page 78.)

Hydrargyrum cum Creta, Gray Powder,—Dose, gr. ss-iv. (See page 78.)

Massa Hydrargyri, Blue Mass, Blue Pill,—Dose, gr. ij-x. (See page 78.)

Alois, Rhubarb, Jalap, Scammony, Sodium Sulphate and Phosphate, and many other hepatic stimulants, may be classed with the cholagogue purgatives:—as also all cathartics which act upon the duodenum, and prevent the absorption of the once-secreted bile;—such being Baptisin, Colocynth, etc.

Action of the various Cathartics. The Laxatives simply relax and unload the intestinal canal, without causing active purgation, or increase of the intestinal secretions. Saline Purgatives produce watery stools, by increasing secretion and stimulating peristalsis. Drastic Purgatives cause violent action of the bowels, in large doses setting up enteritis and symptoms of irritant poisoning. Those which excite a copious flow from the intestinal mucous membrane are called Hydragogue Purgatives, some of which belong to the drastic group (Elaterium, Gamboge), and some to the saline (Potassium Bitartrate). Cholagogue Purgatives are those which remove bile from the body, chiefly by causing increased peristalsis of the duodenum, and thus preventing the reabsorption of the bile therein. The Mercurial Purgatives are now believed not to affect the secretion of bile, but they markedly stimulate the excrementitious glands situated in the lower part of the ileum.

Therapeutics. Cathartics are indicated for the purposes of unloading the bowels of fecal matter or offending materials,—depletion of the vascular system in many diseases,—promotion of absorption in general dropsy, ascites, etc.,—revulsion in inflammation of the brain, etc.,—elimination of the products of the retrograde metamorphosis,—lowering of the temperature in fever, lowering of the blood-pressure,—and excitation of the pelvic circulation. For the last purpose Aloes is the only agent used. Castor Oil is much used, and abused, especially in the puerperal state, where it is very apt to produce hemorrhoids. The leaves of the plant applied to the breasts, as a poultice, are said to promote the secretion of milk. Croton Oil, though a powerfully drastic agent, is one of the most manageable and easily administered purgatives, by reason of the smallness of the dose required.

The various agents, enumerated under this title, have other actions and uses besides that of catharsis, but the limitations of this volume prevent their discussion. Two, which seem to merit separate consideration, are Bryonia and Baptisia, which are described in the following pages.

A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.