drugzzz

Question 1

indications alpha blockers

Answer 1

• benign prostatic hyperplasia where lifestyle changes are insufficient. 5a-reductase inhibitors may be added
• add on rx in resistant HTN

Question 2

mech of action alpha blockers

Answer 2

Majority are specific a1-adrenoceptor blockers
a1-adrenoceptors are found in mainly smooth muscle, including blood vessels and the urinary tract - bladder neck and prostate in particular.
Stimulation = contraction. Blockade = relaxation
alpha1 blockers = vasodilatation and fall in BP, and reduced resistance to bladder outflow

Question 3

adverse effects alpha blockers

Answer 3

postural hypotension
dizziness
syncope
particularly prominent after 1st dose

Question 4

contraindications and cautions alpha blockers

Answer 4

should not be used in pts with existing postural hypotension

Question 5

egs alpha blockers

Answer 5

doxazosin
tamsulosin
alfuzosin

Question 6

antimuscarinics, what are the GU uses?

Answer 6

reduce urinary frequency, urgency and urge incontinence in overactive bladder if bladder training not effective

Question 7

mechanism of action antimuscarinic

Answer 7

• antimuscarininc drugs bind to muscarinic receptors, where they act as a competitive inhibitor of acetylcholine
• contraction of smooth muscle in bladder = PS control. Blocking muscarinic receptors promotes bladder relaxation inc bladder capacity = reduce frequency
• selective for M3 receptor = majority in bladder

Question 8

adverse effects antimuscarinics

Answer 8

dry mouth = common

tachycardia, constipation and blurred vision are also common

Question 9

contraindications / caution antimuscarinics

Answer 9

UTI infec
CNS SE’s can be particularly problematic in the elderly and pts w dementia
adverse effects are more pronounced when combined w other drugs with antimuscarinic effects such as tricyclic antidepressants

Question 10

calcium and vit D uses in GU?

Answer 10

used in CKD to treat and prevent secondary hyperparathyroidism and renal osteodystrophy

Question 11

mechanism of action calcium and vit D in CKD

Answer 11

In severe CKD, impaired phosphate excretion and reduced activation of vit D cause hyperphosphataemia and hypocalcaemia. This stimulates secondary hyperparathyroidism, which leads to a range of bone changes called renal osteodystrophy

Question 12

adverse effects calcium and vit D

Answer 12

oral calcium may cause dyspepsia and constipation

when administered IV for hyperkalaemia calcium gluconate can cause CV collapse if administered too fast

Question 13

calcium interactions

Answer 13

reduces absorption of many drugs incl iron, bisphosphonates, tetracyclines and levothyroxine

Question 14

phosphodiesterase (type 5) inhibitors uses

Answer 14

erectile dysfunction

primary pulmonary htn

Question 15

phosphodiesterase (type 5) inhibitors MOA

Answer 15

sildenafil is a phosphodiesterase inhibitor - it is selective for PDE type 5 found in smooth muscle of corpus cavernosum of the penis and arteries of the lung

• sexual stimulation
• NO released
• No stimulates cGMP
• Causes smooth muscle relaxation = vasodilation and penile engorgement
• PDE5 is responsible for the breakdown of cGMP, so inhibiting this inc cGMP conc = improves penile blood flow and erection

Question 16

drug name for phosphodiesterase (type 5) inhibitors uses

Answer 16

sildenafil (viagra)

Question 17

warnings sildenafil

Answer 17

do not use in pts whom vasodilation could be dangerous e.g recent stroke, ACS, cvd

Question 18

SEs sildenafil

Answer 18

relate to action as vasodilator incl flushing, headache, dizziness and nasal congestion
serious: hypotension, tachycardia and palpitations

Question 19

indications 5a-reductase inhibitors

Answer 19

benign prostatic hyperplasia, second line after a-blockers

Question 20

e.g. 5a-reductase inhibitors

Answer 20

finasteride

Question 21

MOA 5a-reductase inhibitors

Answer 21

Reduce size of prostate gland by inhibiting the intracellular enzyme 5a-reductase which converts testosterone to its more active metabolite dihydrotestosterone
Dihydrotestosterone stimulates prostatic growth