Page 8 - Pharmacognosy-I (02-06-06-102)

Uses:
Senna acts as laxative in small dose and purgative in large dose.
It stimulates peristalsis. It is used in acute habitual constipation. The
use of stimulant laxatives for more than 2 weeks requires medical
supervision.

Precautions:
-Elderly: Elderly patients (from 65 years old) should initially take
half of the normal prescribing dose.
-Children: Not to be used by children under 2 years of age.
children between the ages of 2-12 years should follow proper dose
determined by doctor.
-Pregnant & lactating women: Use in pregnancy is limited to
conditions in which changes in diet or fiber laxatives are not
effective. However, women might experience unpleasant
abdominal cramps.
It should not be used during nursing.

Drug interactions:
- Antiarrhythmics: existing hypokalemia (loss of potassium)
resulting from long-term senna use can also potentiate the
effects of antiarrhythmic drugs.
- Oral contraceptives: serum level of estrogen is decreased when
given with senna due to effect on its absorption. This may affect
its pharmacological action.

Test for Identity: Modified Bontrager’s test (for anthraquinone
glycosides):
1- Boil 0.20 g of powdered senna leaf with 5%FeCl3 and dil.HCL
solution (for 5 min) (to liberate the free aglycones) and filter.
2- Cool and shake with 5 ml ether or benzene (extract the free
aglycones).
3- Separate the yellowish ethereal layer into a clean test-tube.
4-Shake with 1-2 drops of dilute solution of ammonium hydroxide;
a rose red color is produced in the aqueous layer.

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