Which of the following drugs is obtained from a plant source?

Appeared in: KPSC Staff Nurse - 2017

Explanation

Digoxin is a cardiac glycoside, a class of organic compounds that are used to manage heart conditions like heart failure and atrial fibrillation.
It is extracted from the leaves of the foxglove plant, specifically Digitalis lanata or Digitalis purpurea.
This makes Digoxin a primary example of a potent and widely used medication derived directly from a plant source.

Option A: Heparin is an anticoagulant that is obtained from animal sources, not plants. It is commercially prepared from the intestinal mucosa of pigs or the lungs of cattle.
Option C: Insulin is a hormone. While historically sourced from the pancreas of animals (pigs and cows), modern insulin is predominantly produced using recombinant DNA technology (biotechnology), not directly from plants.
Option D: Streptomycin is an aminoglycoside antibiotic. It is derived from a microbial source, the actinobacterium Streptomyces griseus, not a plant.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacognosy: Sources of Drugs as background academic context rather than a clinical decision trigger.
Understanding drug origins (pharmacognosy) is crucial for nurses to anticipate potential patient allergies. For example, a patient with a pork allergy may have a reaction to porcine-derived heparin.
Patient education is a key nursing role. Knowing that a drug like Digoxin comes from a plant can be an interesting fact that helps build rapport and improve medication adherence.
What if a patient with a known pork allergy needs an anticoagulant? The nurse must advocate for the use of a non-porcine source of heparin (e.g., bovine, if available and appropriate) or a different class of synthetic anticoagulant to prevent a hypersensitivity reaction.

How to Approach the Question

First, identify the key concept in the question, which is 'plant source'. This directs you to the field of pharmacognosy (the study of drug origins).
This is a factual recall question. Systematically review each option and try to recall its source.
Consider Heparin: It's a well-known anticoagulant, commonly associated with animal origins (pigs/cows).
Consider Insulin: This is a famous hormone. Recall its history of being extracted from animal pancreases before the advent of biotechnology.
Consider Streptomycin: The '-mycin' suffix is a strong clue for an antibiotic derived from a Streptomyces microbe.
Consider Digoxin: This is a classic cardiac drug linked to the Digitalis (foxglove) plant. This matches the question's requirement, making it the correct answer.

Concept Tested & Keywords

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E6 Pharmacology KD Tripathi Essentials 9e Part 1 pp. 15-17, 113-115

E6 Pharmacology Nursing Lilley 11e Part 1 p. 50-52

Practise the full KPSC Staff Nurse - 2017

Attempt every question from this paper in a timed mock, then review the full solution for each one.