Atropine is an anticholinergic alkaloid found naturally in plants from the Solanaceae family such as deadly nightshade. It acts as an antagonist to acetylcholine by binding to acetylcholine receptors in the nervous system and paralyzing transmission of nerve impulses. This property allows atropine to dilate pupils, increase heart rate by blocking vagus nerve activity, and is used medicinally after heart attacks. Atropine is metabolized in the liver and excreted in urine.

1. Atropine

2. • Background information
• Biological explanation
• Uses in medicine

3. Background
• Atropine is found in many members of the Solanaceae
family of plants
• Mandragora (mandrake) was used in the fourth century
B.C. for treatment of wounds, gout, and sleeplessness
• Roman and Islamic Empires across Europe used
Solanaceae containing tropane alkaloids for
anaesthesia for centuries
• The substance was first synthesized by German chemist
Richard Willstätter in 1901

4. • The toxic alkaloid atropine
comes from the highly
poisonous Deadly
nightshade, common
name belladonna (Italian
for "beautiful lady")
• Women placed atropine-
containing drops in their
eyes to dilate their pupils,
giving them a dreamy look
that was believed to be
attractive. Tragically, many
of these women later
became blind

5. Biological explanation
• Atropine is an ANTICHOLINERGENIC drug
• It is called this because it ‘antagonises’ (works
against) acetylcholine.

6. Atropine as an antagonist
Acetylcholine
Atropine

7. Atropine as an antagonist
Acetylcholine
Atropine

8. Atropine
C17H23NO3

10. SYNAPSE

11. Atropine binds
with the receptors
so acetylcholine
can’t
The nerve
impulse cannot
transmit
This function can
be utilised to
‘paralyse’ certain
nerves

14. Eyes

15. Heart
The vagus nerve normally slows the heart
Atropine blocks the effect of the vagus nerve by
binding with the acetylcholine receptors on the post –
synaptic membrane
The heart rate is no longer inhibited
This may stimulate the heart
Atropine is give after a heart attack

16. Metabolism of atropine
• Up to 50% of atropine is excreted unchanged in the
urine
• The remaining Atropine is destroyed by enzymatic
hydrolysis in the liver