Mechanisms & Dose Responses Flashcards
Name the endogenous ligands of opioids
Endorphins
Enkephalins
Name some agonists of opioids
- Morphine
- Codeine
- Buprenorphine
- Heroin
- Fentanyl
- Methadone
Name an antagonist of opioids
Naloxone
Define endorphins
What are the opioid receptor subtypes
A family of endogenous opioid peptides
μ, δ, κ and NOP
What sort of agonist is buprenorphine
Partial agonist
=> submaximal response
MOA of opioid agonist drugs
How are we trying to change the target for opioid drugs
We are trying to form a biased response to the G protein pathway only, to produce the analgesic effects and NOT affect the beta arrestin pathway (responsible for adverse effects)
What is codeine a constituent of
The opium poppy (with morphine)
How does codeine compare to morphine in terms of addictiveness
Codeine is much less potent than morphine making it less addictive
MOA of naloxone
What activates the beta receptor
Endogenous catecholamine NT (noradrenaline) released from nerve terminals
Adrenaline (epinephrine) can activate beta receptors following release from the adrenal gland
How does adrenaline act as a drug
What sort of drug is propranolol
A non selective beta receptor antagonist - blocks both beta 1 and beta 2
What does salbutamol/albuterol do
It selectively targets the beta 2 receptor subtype, meaning that beta 1 receptors are not activated, which would produce CV effects
What was originally used to treat respiratory conditions
Adrenaline - but it binds to beta 1 and beta 2, so it not only opens airways but activates CV system too to increase HR and BP
Name 3 NSAIDs
Aspirin
Ibuprofen
Paracetamol
What is different about paracetamol as a NSAID
Analgesic and antipyretic but limited anti-inflammatory effects
- thus sometimes not classified as a NSAID
Pathway for prostaglandin synthesis
How does aspirin interfere with prostaglandin synthesis
Inhibits the COX enzyme, thus an ANTI-PLATELET drug
Pathway for cholesterol synthesis
How do statins (e.g. atorvastatin) interfere with cholesterol synthesis
Atorvastatin is a HMG-CoA reductase inhibitor
What is vitamin K involved in
The synthesis of clotting factors
MOA of warfarin
A vitamin K antagonist that interferes in clotting factor synthesis
What is dopamine closely related to
Adrenaline and noradrenaline
MOA of cocaine
MOA of amphetamine
dopamine releasing agent
Inhibits dopamine reuptake
enhanced dopamine effects
MOA of methylphenidate (ritalin)
Dopamine reuptake blocker
=> increased attention
Used to treat ADHD
MOA of SSRIs (e.g. fluoxetine)
Inhibition of serotonin reuptake - selective
MOA of MDMA
A serotonin releaser and reuptake inhibitor
How do benzodiazepines work
Name an example of a benzodiazepine
Diazepam
Treats seizures, difficulty sleeping
MOA of THC (cannabis)
A CB1 receptor agonist
Inhibits postsynaptic neuronal activity
Pathway for bacterial cell wall synthesis
MOA of penicillin
Inhibits transpeptidase, preventing corss-linking occuring and weakens the cell wall of the bacteria
Name the 3 histamine subtype receptors
H1
H2
H3
Colloquial name for H1 antagonists
Anti-histamines
What sort of drug is mepyramine
A H1 competitive receptor antagonist
Effect of histamine on the body
Can reduce electrically-stimulated contraction
MOA of ethanol
- Targets ion channels (both ligand gated and G protein coupled) - particularly GABA-A
- Targets nicotinic and glutamate receptors
- Downstream mechanisms are also believed to be affected by ethanol
