3022. Observations On Their Use

1. The action of every cathartic is followed by a greater or less amount of constipation. This is peculiarly the case with Rhubarb, and is less observable with the salines and Castor Oil.

2. Most cathartics operate on a particular part of the intestinal canal: thus Calomel, Jalap, and Colchicum stimulate the duodenum, and promote the discharge of bile; Aloes and Scammony act upon the colon and rectum; while saline and oleaginous purgatives seem to affect the whole intestinal canal.

3. Their purgative effects in many instances (as Aloes, Croton Oil, and Rhubarb) may be obtained, though not in so constant or uniform a manner, if applied to the skin or to an abraded surface, instead of being taken internally.

4. The constitution, temperament, and idiosyncrasy should always be considered when an aperient is to be administered. Generally speaking, salines are inadmissible in old, debilitated, or anaemic subjects, Aloes in hAemorrhoidal patients, and Mercury in scorbutic cases. It should be laid down as a general rule, that Croton Oil, Elaterium, and other drastic purgatives, should never be given when a milder aperient will answer the purpose.

* Outlines of Pathology, p. 84.

5. It is an observation confirmed by experience, that saline purgatives, particularly the Sulphate of Magnesia, are often productive of hypercatharsis and other serious derangements, to residents in the Tropics.

6. Cathartics are more required in persons of a melancholic than in those of the sanguine temperament, and in women more than in men.

7. Cathartics should never be given to a woman when menstruating, and should be employed with great caution during pregnancy. The uterus, from its contiguity to the rectum, is likely to be affected by Aloes, which should, consequently, be carefully avoided. The milder aperients, as Castor Oil or Conf. SennAe, are preferable.

8. Cathartics of a warm character, as Rhubarb, &c, are best adapted to old age and childhood. Salines, on the other hand, should be avoided-

9. The habitual use of cathartics cannot be too strongly condemned; such a practice lays the foundation of dyspepsia and other serious evils.

10. Cathartics Are Not Required In Every Case Of Costiveness

In some persons, from idiosyncrasy, the bowels are not open for two or three days, or even longer. Such a state is compatible with perfect health. In such cases, it would be useless and injurious to administer aperients. (Dr. Chambers.) In the costiveness of hysterical women, cathartics may prove useless, whilst antispasmodics are indicated.

11. Under a course of cathartics it is advisable to intermit the medicine for a few days, in order to ascertain the real state of the alvine secretions. A knowledge of the characters of the evacuations caused by various cathartics is important. Ignorance of these points may lead to confounding the stools produced by cathartics with the effects of disease. Thus, the evacuations caused by Aloes, abounding as they do with mucus, and sometimes with blood, may easily be confounded with those of dysentery, and those caused by Sulphur may be mistaken for a deficiency of biliary secretion.

12. The time required for the operation of different purgatives is a point of practical importance; thus salines, from their rapidity (three or four hours), are best calculated for febrile and active diseases. Croton Oil generally operates in one or two hours; Jalap, Scammony, Gamboge, and Senna, in three or four hours; Rhubarb and Castor Oil, in four or six hours; and Aloes, from its difficult solubility, requires several hours before it takes effect.

13. The combinations which increase or diminish the activity of purgatives require attention. Thus, the power of Colocynth is increased by a combination with Camphor, whilst that of Aloes, by the same combination, is rendered milder and less irritating. In spasmodic affections, the operation of a cathartic is promoted by the addition of Opium; and in all cases the combination of Senna with the neutral salts, and of Calomel with the resinous cathartics, promotes the cathartic operation. On the other hand, Soap and the aromatic oils render the action of Aloes almost inert; and a few grains of Ext. Hyoscyami, whilst they appear to have no considerable influence in increasing or diminishing the purgative qualities, prevent griping and tenesmus.

14. The facility with which a cathartic may be given in certain cases, as in Apoplexy, Mania, or Asphyxia, requires attention. Thus a drop or two of Croton Oil, placed at the base of the tongue, will often be applicable when the patient is unable or unwilling to swallow a draught or pill.