Pharmacological manipulation of micturition Flashcards
(20 cards)
Label a diagram of the bladder showing the location of receptors
State the action of each of the receptors in the bladder wall
- M3, a1 - stimulatory, causes contraction
- B2, M2 - inhibitory, causes relaxation
To which component of the ANS do the receptors belong?
- Parasympathetic - M3, M2
- Sympathetic - a1, B2
During storage of urine which receptors are dominant?
Sympathetic a1 and B2
What are the 2 classes of drug?
Agonist and antagonist - both subdivided into specific and non-specific
What are the names given to direct acting drugs?
- Agonists - sypmathomimetics, parasympathomimetics
- Antagonists - sympatholytics, parasympatholytics
What is the action of sympathomimetics?
Displace NA
What is the action of parasympathomimetics?
Acetyl choline esterase inhibitors (ACHE), displace ACh
What are the causes of detrusor hypercontractility?
Bladder infection, neurogenic disorders
What is the aim of the drugs given to treat detrusor hypercontractility? Give examples of drugs used
- decrease detrusor activity, need muscarinic antagonist
- e.g. Oxybutalin, Propantheline, Flavoxate, Atropine
What are the problems associated with muscarinic antagonists?
- Side effects reflect systemic distribution
- decreased saliva, GI stasis, tachycardia, excitement, sedation, increases IOP, mydriasis
What are the causes of detrusor atony?
Uriniary retention, neurgenic disorders, overdistension
What is the aim of the drugs given to treat detrusor atony? Give examples of drugs
- Increase detrusor activity with cholinergic agonists/ non-specific muscarinic agonists
- e.g. Bethanechol
What are the side effects associated with Bethanechol?
GI stimulation, hypersalivation, defecation
What are the causes of urethral sphincter incompetence?
Speying bitches, steroids
What is the aim of drugs used to treat urethral sphincter incompetence? Give examples of drugs
- Increase sphincter tone, a1 agonist
- e.g. phenylpropanolamine, ephedrine
What are the side effects associated with drugs used to treat urethral sphincter incompetence?
Hypertension, restlessness, increased IOP
What are the causes of urethral spasticity?
Infections, inflammatory neurological disorders, urethral obstruction, Bethanacol treatment
What is the aim of drugs used to treat urethral spasticity? Give examples of drugs
- Decrease sphincter tone, a1 adrenergic antagonist
- e.g.phenoxybenzamine
What are the side effects associated with phenoxybenzamine?
Hypotension, reflex tachycardia, increased IOP, GI upset
