CR2 KCP 2 - Response to xenobiotics Flashcards
Alpha 1 receptors location & function
- Vascular smooth muscles, smooth muscles around neck of bladder & prostate, GI sphincters, radial iris muscle
- Contraction
Alpha 2 receptors location & function
- Presynaptic neuron, pancreas
- Inhibition of neurotransmitter release, decrease insulin
Beta 1 receptors location & function
- Heart & kidney
- Myocardial stimulation, renin release
Beta 2 receptors location & function
- Respiratory, uterine & vascular smooth muscle, liver, pancreas, muscle spindles
- Smooth muscle relaxation, glycogenolysis, increase glucagon, tremors
Beta 3 receptors location & function
- Adipose tissue
- Lipolysis
D 1 receptors location & function
- Renal vascular smooth muscles
- Dilation
D 2 receptors location & function
Nerve endings in the CNS & GIT
- Modulation of transmitter release, CNS stimulation
Sympathomimetic classes
- Direct acting (selective & non-selective)
- Mixed acting
- Indirect acting (releasing agent, uptake inhibitor & MAO/COMT inhibitor)
Non-selective alpha blocker
Reversible: Phentolamine
Irreversible: Phenoxybenzamine
Selective alpha blockers
Alpha 1: Prazosin
Alpha 2: Yohimbin
Non-selective beta blocker with no ISA
Propranolol
Selective beta 1 blockers
with ISA: Pindolol (non-selective)
without ISA: Metoprolol
Alpha + Beta blocker
Labetolol
Direct acting cholinergic agonists
M&N: Acetylcholine
M: Pilocarpine, Methacholine
N: Nicotine, Succinyl choline (Suxamethonium chloride)
Reversible indirect acting Cholinesterase inhibitors
Short-acting: edrophonium
Medium-duration: neostigmine (proserine), physostigmine (eserine)
irreversible indirect acting Cholinesterase inhibitors
Organophosphates:
- Soman & Sarin (nerve gas)
- Malathion (insecticide)
Muscarinic blockers
- Atropine
- Scopolamine
- Ipratropium
Nicotinic blockers
- D-tubocurarine
- Succinylcholine
- Mecamylamine
Narrow therapeutic index drugs
- Barbiturates
- Theophylline
- Cardiac glycosides
- Warfarin
Wide therapeutic index drugs
- Benzodiazepines (e.g. Diazepam)
- Penicillin
- Cephalosporines (e.g. Cefadoxil)
- Acetaminophen (e.g. Paracetamol)
Adverse drug reaction (ADR) types
A - augmented
B - bizarre
C - chronic
D - delayed
E - withdrawal or end of use
F - failure
Drug-drug interaction drawbacks
- increased toxicity
- reduced efficacy
- inconvenience
- increased cost
Drug-drug interactions benefits
- reduced toxicity
- increased efficacy
- increased convenience
Ca, Mg, iron containing foods effect on tetracycline
Inhibits oral absorption
Vitamin K effect on warfarin
Counteracting effect; may precipitate thrombosis
Cheese syndrome
MAO inhibitors prevent breakdown of tyramine from cheese
Grapefruit juice’s bioflavonoids contain CYP450 inhibitors that reduce metabolism of…
- H1 blockers
- Statins
- Calcium channel blockers
- Itraconazole
- Amiodarone
Drug-herb interactions
- St. John’s wort induces CYP450, interacts with multiple drugs
- Gingko & ginseng reduce platelet aggregation & enhance risk of bleeding by Aspirin & Warfarin
Acetylcholine sites
- All preganglionic sites
- All postganglionic parasympathetic endings
- Sympathetic to sweat gland
- Motor nerve endings in skeletal muscles
Noradrenaline sites
All postganglionic sympathetic nerve endings EXCEPT sweat glands
Noradrenaline & Adrenaline site
Adrenal medulla
Dopamine site
Renal vasculature
Alpha 1 antagonist CVS effect
vasodialtion
↓ peripheral resistance
↓ blood pressure
ADR: MAY CAUSE POSTURAL HYPOTENSION
Alpha 2 antagonist CVS effect
↑ sympathetic outflow
tachycardia
Alpha blockers effects:
- facilitate insulin release
- facilitate miosis
- nasal stuffiness
- ejaculation failure
- ↓ smooth muscle tone in prostate & bladder neck; ↓ resistance to urine outflow in BPH
Beta blockers bring about an antihypertensive effect by:
↓ heart rate
↓ contractility
↓ cardiac output
↓ renin release
↓ TPR (long-term)
Beta blockers bring about an antiarrhythmic effect by:
↓ sinus rate
↓ ectopic pacemaker activity
↓ conduction (membrane stabilization)
Beta blockers bring an anti-ischemic effect by:
↓ cardiac work
↓ oxygen demand
Beta blockers help in congestive cardiac failure by:
reducing sympathetic tone
OD CAN WORSEN CCF
Autacoids classes
Amines - histamine, serotonin
Lipids (Eicosanoids) - leukotriene B4, prostaglandin I2
Peptide - angiotensin, bradykinin
PGE1 analogues
- Misoprostol: prevent NSAID induced peptic ulcer & treatment of peptic ulcer
- Alprostadil: treatment of erectile dysfunction
PGE2 analogues
Dinoprostone: include abortion & labor induction (cervical ripening)
PGEF2α analogues
Latanoprost: glaucoma treatment
Histamine H1 receptors
- smooth muscle, endothelial cells
- causes acute allergic responses & inflammation
Histamine H2 receptors
- gastric parietal cells
- increased secretion of gastric acid
Histamine H3 receptors
- central nervous system
- modulating neurotransmission
H1 antihistamine: Diphenhydramine (gen1)
- cross BBB
- short-acting (4-6 hours)
- blocks muscarinic & α-adrenergic receptors
H1 antihistamine: Cetirizine, Loratadine (gen2)
- do not cross BBB (peripheral H1 binding only)
- long-acting (12-24 hours)
- selective to H1 receptors only
1st gen antihistamine ADR
- CNS depression
- orthostatic hypotension
- anticholinergic effects: dry mouth, urinary retention, blurred vision
2nd gen antihistamine ADR
- CNS depression minor risk
- inhibit CYP450
increases QT interval; risk for arrhythmia (terfenadine)
1st gen antihistamine clinical use
- acute allergic reactions
- motion sickness
- morning sickness
- vertigo
- antitussives (cough med)
2nd gen antihistamine clinical use
- allergic rhinitis (hay fever)
- allergic conjunctivitis
(chronic allergic conditions)
