Toxins and medicines Flashcards
(15 cards)
What are drugs?
A chemical substance of known structure, not a nutrient, which, when administered to a living organism, produces a biological effect.
What are medicines?
Chemical substances, of known or unknown composition, given to achieve a therapeutic effect.
A substance can be a medicine but not a drug, or a drug but not a medicine.
What are recreational drugs?
The aim is to change perception, consciousness, personality or behaviour.
What are performance enhancing drugs?
The aim is to enhance an otherwise normal function such as strength or memory.
What is a toxin?
A chemical substance given to cause harm.
A substance can be a toxin but not a drug.
Or can be a drug but not a toxin depending on dose and method of delivery.
What is Tetrodotoxin?
Blocks voltage-gated Na+ channels.
What is Apamin?
Blocks some types of Ca2+ activated K+ channel.
This increases excitability of axons, especially in sensory neurones.
What are omega-conotoxins?
Used to study neurotransmission, by blocking Ca2+ channel subtypes.
What is Botulinum toxin?
Causes a form of food poisioning.
Is a useful drug in small doses which blocks exocytosis.
Uses for cosmetics, decrease muscle tone - oesophagus, decrease secretions - sweat glands.
What is a-latrotoxin?
Binds to a protein only found on neurones, inserts a pore to allow Ca2+ into the terminal.
Increases exocytosis of neurotransmitter.
What is atropine?
For the emergency treatment of slow heart rate.
Blocks the effects of muscarine.
What is Muscarine?
Activates muscarine receptors, and mimics the activation of parasympathetic nerves.
What is physostigmine?
Inhibits acetylcholinesterase, the enzyme which breaks down acetylcholine.
Amplifies parasympathetic stimulation.
What is Galantamine?
Act on nicotinic receptors to increase their activity - positive allosteric modulator.
Also has anticholinesterase activity.
Used in treatment of Alzheimers disease.
What is morphine?
Activates presynaptic receptors (opiate receptors) that tend to inhibit neurotransmission.
