Pharmacology Flashcards
Name 4 drug targets (4)
Receptors
Enzymes
Transporters
Ion channels
Describe the difference between tolerance and desensitisation?
Give three examples of angiotensin II receptor blockers.
Give four ways that drugs can move between intracellular, extracellular and plasmodia fluid.
Simple diffusion
Non-Ionic Diffusion
Facilitated diffusion
Active Transport
what do positive chronotropes do to the heart?
increase heart rate
what do positive inotropes do to the heart?
increase contractility
Give two examples of loop diuretics and how do they work?
Give three examples of thiazide diuretics and how do they work?
Give two examples of aldosterone antagonist diuretics and how do they work?
How do bisphosphonates work?
Give three examples of bisphosphonates and their respective doses.
Three key side effects of bisphosphonates?
What are the four classes of anticoagulant?
What factors does dalteparin affect?
What factor does apixaban inhibit?
What factor does dabigatran inhibit?
Give a list of the DOACs
How does aspirin work?
What type of drug is clopidogrel?
Give three examples of COX2 inhibitors.
What is diclofenac?
Give two examples of non-dihydropyridines and where do they act.
Three key side effects of CCBs?
What do dihydropiridines end in?
Which second line diabetes drugs don’t cause weight gain?
Three main side effects of biguanides?
Give an example of a sulfonylurea and two side effects of it.
Two main side effects of pioglitazone?
Give an example of a DPP4 inhibitor and a key side effect.
Give an example of an SGLT-2 inhibitor and its two key side effects.
What drug is given for paracetamol overdose?
N-acetyl cysteine
(restores hepatic glutathione which is essential for metabolism of a toxic paracetamol metabolite)
Name four anti-emetics and give which one is contraindicated in Parkinson’s.
Give a class of antidepressant other than SSRIs, SNRIs and tricyclics.
Monoamine oxidase inhibitors
(also used in Parkinson’s)
How do tamsulosin work to treat BPH?
Alpha blockers - causes smooth muscle relaxation of the bladder neck by blocking adrenergic alpha receptors.
Mechanism of action of methotrexate?
Dihydrofolate reductase inhibitor
What is pharmacokinetics?
what the body does to the drug (ADME)
What’s a summative drug interaction?
When the effect of two drugs given in combination equals the effect of the drugs when given alone
1+1=2
What’s a synergistic drug interaction?
When the combined effect of two or more drugs is greater than the sum of effects when given separately.
1+1>2
e.g paracetamol and morphine
what is an antagonism/blockade interaction?
When the effect of one drug cancels out the effect of another drug.
1+1=0
what is potentiation in drug interactions?
when one drug is made more potent by another drug. 1+1=1+1.5
pharmacokinetics - what does ADME stand for?
Absorption
Distribution
Metabolism
Excretion
What is the potency of a drug?
potency = amount of drug needed to achieve a response
What’s a partial agonistic drug?
a drug that binds to a receptor but causes less of a reaction than the substance that normally binds to the receptor
Definition of selectivity of a drug?
the degree to which a drug acts on a given site relative to other sites. (i.e non-selective drugs bind to lots of other sites as well as the target site) - however high concentrations may reduce selectivity!
Definition of specificity of a drug?
specificity of a drug related to the number of mechanisms involved. i.e non specific drugs results in effects through several mechanisms of action.
What is pharmacodynamics?
what the drug does to the body (and how)
affinity, potency, efficacy
What is affinity of a drug?
a measure of how well it binds to the target receptor
What is the first pass effect?
It’s the fraction of an orally administered drug lost during absorption, generally due to the gut wall and metabolisation by the liver.
(second pass is when venous blood passes through the liver naturally i.e through the hepatic artery or splenic/portal vein)
How are drugs transported through the bloodstream?
Partly free (unbound) and partly reversibly bound to blood components (plasma proteins, blood cells etc)
What are the three main plasma proteins that drugs bind to?
- albumin (acidic drugs usually bound more extensively)
- alpha-1 acid glycoprotein (basic)
- lipoproteins (basic)
How does ionisation of a drug affect its ability to cross cell membranes?
Un-ionised forms is usually lipid soluble, able to pass through membrane easier
Ionised form usually has low lipid solubility, difficulty passing through cell membranes
Definition of pKa?
The pH at which concentrations of the unionised and ionised forms of a substance are equal.
What is zero clearance in the kidney? Give an example molecule
When a molecule doesn’t leave the blood during filtration e.g albumin
Or it’s when a molecule freely filtered by the kidneys but 100% reabsorbed.
e.g glucose
What is complete clearance by the kidney? Give an example
When a molecule is freely filtered but 0% reabsorbed
+ 0 secretion from blood to nephron
e.g Inulin
What type of molecule can pass through the blood brain barrier easier?
Lipophilic molecules
definition of an inverse agonist?
a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist
How do local anaesthetics work?
They block the voltage gated sodium channels and so stop influx of sodium into neurons, therefore no action potential and transmission of pain signal to the CNS
What two types of receptors are found in the parasympathetic nervous system?
What cranial nerves are parasympathetic?
What receptors do you find on the effector organs of the sympathetic nervous system?
What’s the only neurotransmitter used by the parasympathetic NS?
Where do you find noradrenaline in the nervous system?
What receptors are found in the sympathetic NS?
where’s the only place you find nicotinic receptors in the sympathetic NS?
how many types of muscurinic receptor are there and which ones are Gq coupled?
what are the two types of nicotinic receptor?
what is ACh made from in the presynaptic neurone?
How is an adverse drug reaction (ADR) different from a side effect?
Always harmful, more unexpected than a side effect
What does ABCDE of ADRs stand for?
What receptors do opioids work on?
Mu, kappa and delta
What happens when an opioid binds to a receptor?
- Opioid stimulates receptor
- G proteins released and stops
- Calcium influx blocked
- K+ efflux blocked
- Depolarisation blocked
Common side effects of opioids?
Respiratory depression
N&V
Constipation
Common side effects of PPIs?
prolonged use in elderly can increase risk of fractures
In Rawlin’s and Thompson’s classification of adverse drug reactions, which type is a predictable reaction and which is unpredictable.
