What pharmacologically relevant parameter is represented by AUC of a drug concentration/time curve?
Drug exposure over time
Which products of arachydonic acid metabolism have antithrombotic effects?
PGI2 PGD2
What inflammatory responses are caused by the production of leucotrienes from phospholipids?
Increased vascular permeabilityVasodilationBronchoconstriction
Which product of AA metabolism is a pyrogen?
PGE2
What inflammatory mediator is produced from acylPAF and what is its effect within the body?
Platelet Activating Factor Chemotaxis, increased vascular permeabilit, vasodilation, bronchoconstriction
Which of the COX enzymes is represented by this diagram? How do you know? What type of cells is it present on?
COX-2
The characteristic “side pocket”
Found on activated inflammatory cells
What are the side effects of NSAID use? Explain
Reduced clotting ability - downregulation of PG and platlets
Gastric ulceration - downregulation of PG causing increased H+ secretion on mucosal surfaces
Hepatic damage
Altered renal blood flow
Why does lack of selctivity of COX enzymes by NSAIDs have systemic side effects on the body?
COX1 enzymes are present in most cells and are involved in homeostasis, their widespread distribution therefore leads to widespread effects if activated
What are the metabolic side effects of steroid use?
How can the systemic effects be decreased?
Use of topical steroids (local effects only)
This class of drugs acts to increase cAMP therefore causing relaxation of smooth muscle causing bronchodilation.
Identify a drug from this class.
Methyxanthines
Theophylline
“Drugs which act by altering transcription, they act upon the HPA axis and are endogenously secreted by the adrenal gland”
Steroids
How do NSAIDs work?
They inhibit cyclooxygenase (COX) (enzyme for synthesis of PGs) which then inhibits prostaglandins (as PGs are pyretic (fever), pro inflammatory & hyperalgesic (increased sensitivity to pain)).
What does COX inhibition lead to?
PGs mainly increase blood flow and enhance swelling & pain, also increase body temperature. Therefore inhibition leads to:
[Will not reduce heat, stress or exercise induced hyperthermia as these are not mediated by PGs]
What are contra indications of NSAIDs?
Identify three beta2 agonists which are used to treat asthma.
What biological effect do they have on the body?
Terbutaline
Albuterol
Clenbuterol
This drug acts as a respiratory stimulant by acting on the respiratory centre of the brain.
Useful with recusitation of neonates.
Doxapram
This class of drug acts as a gastric irritant and increases vagal tone.
What effect does increased vagal tone have on the respiratory system?
Expectorants
Increased mucocilliary escalator, increased mucus production
This mucolytic is ineffective in the presence of protein from infection or inflammation.
Bromhexine HCl
Describe the mode of action of N-acetyl cysteine.
What class of drug is it from?
Mucolytic
Breaks disulphide bonds between mucous molecules.
How do opioid antitussive drugs work?
They inhibit kappa and lambda opioid receptors and therefore reduced the animals response to irritants.
They directly inhibit the cough
Bronchodilation can also be achieved by antagonism of the parasympathetic nervous system, what class of drug is used for this?
Name a PNS anatagonist.
Cholinergics - increase smooth muscle relaxation
Bethanechol
This parasympathetic antagonist increases the drainage angle of the eye by causing pupil miosis. It is therefore used to treat which painful eye condition?
Pilocarpine is used to treat glaucoma