Bladder & drugs Flashcards
What is the 3 functions of the bladder
Micturition
Storage of urine
Temperature control
What is the innervation of the bladder
Sympathetic & parasympathetic
From where does the sympathetic nervous system originate from
Superior & inferior hypogastric plexus
From where does the parasympathetic nervous system originate from
Pelvic splanchnic nerve S2-4
What is the 2 functions of the sympathetic nervous system
Relaxation of detrusor via B2
Contraction of trigone & sphincter via a1
What innervation is responsible for sensation of distended or irritated bladder
Parasympathetic
What is the 2 functions of the parasympathetic nervous system
Contraction of detrusor via M3
Relaxation of trigone & sphincters via M3
What is the 3 autonomic nervous system neurotransmitters
Acetylcholine
Norepinephrine/epinephrine
Non-acetylcholine like serotonin & dopamine
What is the 5 basic steps & sites of drug action
- Synthesis of transmitter
- Storage of transmitter
- Release of transmitter
- Interaction of transmitter w/ receptor on effector cells
- Removal/degradation/recycling of transmitter
What is the steps w/ cholinergic receptor & drug interactions
- Synthesis of acetylcholine inhibited by hemicholinium
- Storage of acetylcholine in vesicle that protects from degradation
- Release of acetylcholine blocked by botulinum toxin or stimulated by spider venom
- Interaction of acetylcholine w/ receptor on effector cells
- Degradation & recycling of acetylcholine
What is the effect of organophosphate poisoning on the bladder
Acetylcholine increase the tone of detrusor muscle that cause expulsion of urine/urinary urgency
What is 3 drugs that are cholinergic agonist & their effects
- Bethanechol: use in urinary retention
- Physostigmine: increase bladder motility
- Neostigmine: prevent postoperative abdominal distention & urinary retention
What is 3 examples of cholinergic antagonist
- Selectively block muscarinic receptors of parasympathetic nerves
- Ganglionic blockers blocking nicotinic receptors of parasympathetic & sympathetic
- Neuromuscular blocking agent interfere with/ transmission of efferent impulses to skeletal muscle & used as smooth muscle relxant anesthesia
What is the 2 effects of drugs on the bladder
- Urinary retention
- Urinary incontinence
What 2 drugs cause urinary retention
- Anti cholinergic: atropine & oxybutinin (used in overactive bladder)
- Drugs w/ anti cholinergic side effect: tricyclic antidepressant (imipramine in children)
What 3 substances cause urinary incontinence
- Diuretics
- Alcohol
- Caffeine
What is the 2 drugs used in BPH
- 5 alpha reductase inhibitor
- A1 adrenergic antagonists
What is the effect of a1-adrenergic antagonist
Relieve outlet obstruction of bladder by reducing tension of prostatic smooth muscle
What is 2 side effects of a1-adrenergic antagonist
Orthostatic hypotension after 1st dose
Dizziness
What is the indication of a1-adrenergic antagonist
Hypertension
BPH
How long does it take for a1-adrenergic antagonist to have an effect
2-4 weeks
What does a1-adrenergic antagonist not affect
PSA levels
Size of prostate
What is an example of a1-adrenergic antagonist drug
Doxazosin
What is the effect of 5 alpha reductase inhibitor
Reduce the size of prostate gland & PSA
What is 2 side effects of 5 alpha reductase inhibitors
Decreased libido
Ejaculatory or erectile dysfunction
How long does it take for 5 alpha reductase inhibitors to work
6-12 months
What is an example of 5 alpha reductase inhibitor
Finasteride
What is the ideal treatment for BPH
Combination therapy due to synergic effect
