Block A Lecture 2: Where do Drugs Act? Flashcards
What are the top 2 receptor types which are targets for drugs?
G protein-coupled receptors (GPCRs) - 30%
Nuclear hormone receptors - 4%
(Lecture 2, Part 1, Slide 3)
What do agonists and antagonists do to cell activity?
An agonist enhances cellular activity whereas an antagonist blocks cellular activity
(Lecture 2, Part 1, Slide 5)
How can new drugs often be made?
By tweaking the structure of already existing drugs to try improve on their pharmacological properties
(Lecture 2, Part 1, Slide 7)
Is salbutamol an agonist or antagonist?
Agonist (beta-2 adrenergic receptor)
(Lecture 2, Part 1, Slide 8)
What is the first step of salbutamol’s mechanism of action to combat asthma?
Salbutamol activates ß-2 adrenergic receptors in the smooth muscle of bronchioles in the lung
(Lecture 2, Part 1, Slide 8)
What happens in salbutamol’s mechanism of action after it activates ß-2 adrenergic receptors in the smooth muscle of bronchioles?
ß-2 adrenergic receptors, activate the enzyme adenylyl cyclase
(Lecture 2, Part 1, Slide 8)
What happens in salbutamol’s mechanism of action after ß-2 adrenergic receptors activates the adenylyl cyclase?
It converts ATP into cyclic adenosine monophosphate (cAMP)
(Lecture 2, Part 1, Slide 8)
What happens in salbutamol’s mechanism of action after adenylyl cyclase converts ATP into cyclic adenosine monophosphate (cAMP)?
cAMP inhibits calcium release, resulting in smooth muscle relaxation
(Lecture 2, Part 1, Slide 8)
Are anti-histamines antagonists or agonists?
Antagonists
(Lecture 2, Part 1, Slide 11)
What are anti-histamines antagonists for?
Histamine H1 receptors
(Lecture 2, Part 1, Slide 11)
What do antihistamines treat?
Allergic reactions
(Lecture 2, Part 1, Slide 14)
Are drugs mainly agonists or antagonists?
Antagonists
(Lecture 2, Part 1, Slide 15)
What are beta blockers antagonists for?
Beta 1 receptors
(Lecture 2, Part 1, Slide 15)
What are beta blockers used to treat?
Heart arrythmias (irregular heart beat)
(Lecture 2, Part 1, Slide 15)
What do antagonists of histamine H2 receptors treat?
Stomach ulcers
(Lecture 2, Part 1, Slide 15)
What do antagonists of angiotensin II receptors treat?
High blood pressure (by lowering it)
(Lecture 2, Part 1, Slide 15)
What do antagonists of purinergic (P2y12) receptors on platelets treat and how?
Heart attacks - by inhibiting platelet aggregation
(Lecture 2, Part 1, Slide 15)
Is the contraceptive pill an agonist or antagonist?
Agonist
(Lecture 2, Part 1, Slide 16)
What type of drug is aspirin?
An enzyme inhibitor
(Lecture 2, Part 2, Slide 5)
What is the full chemical name of aspirin?
Acetyl Salicylic Acid
(Lecture 2, Part 2, Slide 6)
What does aspirin inhibit?
It inhibits both isoforms of the cyclo-oxygenase inhibitor (COX inhibitor), COX-1 and COX-2
(Lecture 2, Part 2, Slide 7)
What is the cyclo-oxygenase inhibitor responsible for?
Converting arachidonic acid into TXA2 and PGE 2 prostaglandins
(Lecture 2, Part 2, Slide 7)
What is PGE2?
A prostaglandin involved in inflammation
(Lecture 2, Part 2, Slide 9)
What mediates the creation of PGE2?
COX-2
(Lecture 2, Part 2, Slide 9)
What is TXA2 (thromboxane A2)?
A prostaglandin like product involved in platelet aggregation during clotting
(Lecture 2, Part 2, Slide 9)
What mediates the creation of TXA2 (thromboxane A2)?
COX-1
(Lecture 2, Part 2, Slide 9)
In addition to reducing inflammation by inhibiting COX-2, what else is aspirin good for and how does it do this?
Preventing secondary heart attacks (in combination with other drugs) - by inhibiting COX-1
(Lecture 2, Part 2, Slide 12)
What is the full name of ACE inhibitors?
Angiotensin Converting Enzyme inhibitors
(Lecture 2, Part 2, Slide 13)
What does ACE (Angiotensin Converting Enzyme) do?
Convert angiotensin I to II
(Lecture 2, Part 2, Slide 14)
What are 3 examples of ACE inhibitors?
Captopril
Enalapril
Cilazapril
(Lecture 2, Part 2, Slide 18)
How do ACE inhibitors lower blood pressure?
ACE is responsible for converting angiotensin I to II. Angiotensin II is a vasoconstrictor, which results in blood pressure increasing. ACE inhibitors inhibit ACE, preventing angiotensin II being formed, meaning vessels do not become constricted, lowering blood pressure
(Lecture 2, Part 2, Slide 19)
What are 3 examples of enzyme inhibiting drugs (other than ACE inhibitors)?
Statins
Sildenafil (Viagra)
Nevirapine
Penicillin
(Lecture 2, Part 2, Slides 20 and 21)
What do statins do?
Lowers cholesterol and prevents heart attacks
(Lecture 2, Part 2, Slide 20)
What does sildenafil (Viagra) do and how?
It helps with erectile disfunction by inhibiting the enzyme which breaks down cGMP
(Lecture 2, Part 2, Slide 20)
What is nevirapine used to treat and how does it treat it?
Used in treatment of HIV and AIDs as it is a non-nucleoside reverse transcriptase inhibitor (NNRTI) of HIV-1
(Lecture 2, Part 2, Slide 20)
How does penicillin kill bacteria?
By the beta-lactam ring binding to DD-transpeptidase, inhibiting its cross linking activity and preventing a new cell wall being formed
(Lecture 2, Part 2, Slides 21 and 22)
What happens to a bacteria that doesn’t have a cell wall due to penicillin?
It becomes vulnerable to outside water and molecular pressures, causing the cell to die quickly
(Lecture 2, Part 2, Slide 21)
