Pharm Term 2a Flashcards
Give a drug that only blocks If current (funny current)
ivabradine
Two classes of CCB
TWO CLASSES:
Rate slowing (Cardiac and smooth muscle actions)
Phenylalkylamines (e.g. Verapamil)
Benzothiazepines (e.g. Diltiazem)
Non-rate slowing (smooth muscle actions – more potent)
Dihydropyridines (e.g. amlodipine)
Non rate slowing Calcium antagonists have pretty much No effect on the heart. However, Profound vasodilation can lead to reflex tachycardia
What are the side effects of verapamil?
- Bradycardia and AV block (too much Ca2+ channel block, this happens when you take it chronically and their effects can build up)
- Constipation (blocked Gut Ca2+ channels,=reduced motility)
Give an example of ARB
Lorsartan
‘sartan’ = ARBs
Give an example of ACE inhibitor
enalapril, ramipril
‘pril’= ACE inhibitors
give an examples of dihydropyridines (non rate limiting CCB)
Nitrendipine
Amlodipine
Nisoldipine
Nitrendipine and nisoldipine are from first year
a1 blocker example
prazosin
What are the side effects of verapamil?
- Bradycardia and AV block (too much Ca2+ channel block, this happens when you take it chronically and their effects can build up)
- Constipation (blocked Gut Ca2+ channels,=reduced motility)
What are the side effects of dihydropyridines?
- Ankle oedema - vasodilation allows more blood into capillary beds and so increased hydrostatic pressure
- Headaches/flushing - vasodilation in brain and peripheral vasodilation causes flush
- Palpitations- baroreceptor reflex due to reduced TPR
how does adenosine work
VSMC:
Bind to A2 (adenosine 2) receptors and stimulates cAMP to cause relaxation. (B2 also uses cAMP to cause relaxation)
SAN and AVN:
Bind to A1, decreases cAMP and slows the heart down. Nb this is the same mechanism as M2 receptors for para NS. Ach from vagus binds to M2 receptors which reduces cAMP. See notes for more details
What is the target of cardiac glycosides like digoxin?
Na+/K+ ATPase
side effects of amiodarone
Amiodarone accumulates in the body (t½ 10 - 100days)
Has a number of important adverse effects including:
- photosensitive skin rashes
- hypo- or hyper-thyroidism
- pulmonary fibrosis
Uses of: adenosine verapamil amiodarone digoxin
adenosine: terminate supraventricular tachyarrhythmias
verapamil: Reduction of ventricular responsiveness to atrial arrythmias
amiodarone: supraventricular and ventricular tachyarrhythmias/ re-entry circuit problems
digoxin: atrial fibrillation and flutter
most potent cannabinoid
delta 9 THC
what is the potent metabolite from the breakdown of the cannabinoid THC
11-OH-THC
more potent than delta 9 THC
name an endogenous cannabinoid
anandamide
we have CB1 and CB2 receptors for a reason
Cannabinoid receptor location
CB1 - brain
CB2 immune cells
which area in the brain does cannabis interact with which causes the psychotic/schizophrenic effects? What is this area involved in?
anterior cingulate cortex
-Involved in error detection
eg GREEN (this is grey)
-Involved with performance monitoring with behavioural adjustment in order to avoid losses (eg you are talking + driving on an easy road then theres a slope and you need to focus so u stop talking- example of performance monitoring and adjustment )
long term cannabis users = hypoactivity in ACC
What are the two main groups of neurones that are involved in stimulating appetite?
MCH (melanin concentrating hormone) neurones
Orexin neurones
how does cannabis increase hunger
Cannabis inhibits the inhibitory effect of GABA on MCH neurones, thus leading to increased MCH firing
Cannabis also directly stimulates orexin production
This leads to hunger
How does cannabis cause tachycardia and vasodilation
act on TRPV1 receptor rather than CB receptors
vasodilation common in conjunctivae hence blood shot eyes
State 4 drugs that are either cannabinoid agonists or antagonists.
Agonists: Dronabinol - act like Delta-9-THC Nabilone - act like Delta-9-THC Sativex - act like Delta-9-THC + cannabidiol Antagonists: Rimonabant – CB1 antagonist
how does cannabis cause memory loss
inhibits production of BDNF(brain derived neurotrophic factor) which is involved in memory formation in hippocampus
What is sativex used for
Treatment for symptom improvement in adult patients with moderate to severe spasticity due to multiple sclerosis
What can Rimonabant be used for?
Anti-obesity medication (it was removed from the market because it was shown to cause depression and suicidal thoughts)
weed makes you hungry
cocaine half life
20-90mins v quick
where is cocaine metabolised
liver and plasma hence very short half life
to ecognine methyl ester + benzoylecognine
half life of nicotine
1-4 hours
2 side effects of cocaine
CVS (myocardial infarction)
Hyperthermia
where is nicotine broken down and what is it broken down into
liver
into cotinine which is excreted via urine
Name a drug used in alcohol aversion therapy
disulfiram
aldehyde dehydrogenase inhibitor, leads to increase in acetaldehyde and hence the person will feel ill after drinking alcohol as acetalddehye is toxic
2 enzymes that convert alcohol to aldehyde in the liver and 1 enzyme that converts aldehyde to acetic acid
alcohol dehydrogenase and mixed function oxidase
then aldehyde dehydrogenase
What does dabigatran block
It is an anticoagulant involved in blocking factor 2a during the initiation stages of coagulation.
What does rivaroxaban block
factor 10a inhibitor (part of the prothrombinase complex)
Drug that increase antithrombin activity?
Heparin, 2 types:
heparin and low molecular weight heparin eg Dalteparin
3 stages of coagulation (sohag structure)
initiation- activation of thrombin by prothrombinase complex
amplification- thrombin then activates platelets which makes them sticky and aggregate
Propagation- Now we have activated platelets plus a lot of thrombin as well. Thrombin converts fibrinogen to fibrin
summarise amplification stage
F2a binds to PAR receptor which leads to ADP release from platelets. ADP bind to P2Y12 receptor via autocrine signalling.
PAR and P2y12 activation lead to COX activation, which produces Thromboxane A2. Thromboxane A2 allows Gp2b/3a production which allows platelets to stick together
name an irreversible COX1 inhibitor
aspirin
name a P2y12 receptor antagonist (ADP receptor antagonist)
Clopidogrel
Name a Gp2b/3a receptor antagonist
abciximab
name a thrombolytic
alteplase - recombinant tPA
