Page 12 - Pharmacognosy-I (02-06-06-102)

- Overdosage leads to cardiac rhythm disorders, life-threatening
ventricular tachycardia, as well as atrial tachycardia with
atrioventricular block. Moreover, central nervous system disorders
as: visual disorders, depression and hallucinations may occur.
Drug Interactions:
The simultaneous administration of arrhythmogenic substances
(e.g., sympathomimetics), increases the risks of cardiac
arrhythmias.

Allied Drugs:

Digitalis lanata: The leaves are linear lanceolate, sessile, ciliate
margin, and acuminate apex. The leaves are twice to four times as
active as official drug. It contains the cardiac glycosides digitoxin,
gitoxin and lanatosides A, B, C, D.

Test for identity:
Keller-Killiani Test: (test for digitoxose)
1. Boil 1 g of powder with 5 ml of 70% alcohol for 2-3 minutes,
filter, dilute with 5 ml water.
2. Add 0.5 ml of lead acetate, shake, filter, shake with 5 ml
chloroform, allow to separate.
3. Evaporate the chloroform in a porcelain dish, cool, dissolve in 3
ml glacial acetic acid, add 2 drops of ferric chloride solution.
4. Transfer this solution in a test tube, add 2 ml of concentrated
sulphuric acid; a reddish-brown layer forms at the junction of the 2
phases and the upper layer slowly becomes bluish green.

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