PHARMACOLOGY

Question 1

what drug class is alendronic acid?

Answer 1

a nitrogen-containing, second generating bisphosphonate

Question 2

what is the mechanism of alendronic acid?

Answer 2

it inhibits farnesyl pyrophosphate synthase in osteoclasts which causes a reduction in osteoclast activity, further reducing bone resorption and turnover. it causes a net gain in bone mass

Question 3

what are the indications of alendronic acid?

Answer 3

treatment of post-menopauseal osteoporosis, corticosteroid-induced osteoporosis and pagets disease

Question 4

what are the side effects of alendronic acid?

Answer 4

Alopecia; anaemia; arthralgia; asthenia; constipation; diarrhoea; dizziness; dysphagia; electrolyte imbalance; eye inflammation; fever; gastritis; gastrointestinal discomfort; headache; influenza like illness; malaise; myalgia; nausea; oesophageal ulcer (discontinue); oesophagitis (discontinue); pain; peripheral oedema; renal impairment; skin reactions; taste altered; vomiting

Question 5

what drug class is calciferol?

Answer 5

a bioactive vitamin D

Question 6

describe how cholecalciferol (vitamin D3) is obtained?

Answer 6

in the diet or activation of 7-dehydrocholesterol by UV rays in the skin

Question 7

how is cholecalciferol activated to calcitriol?

Answer 7

cholecalciferol is activated by 25-hydroxylase in the liver to form 25-hydroxyvitamin D3.
this is then activated in the kidneys by 1-alpha-hydroxylase to from 1,25-dihydroxyvitamin D3 (calcitriol)

Question 8

How can calcitriol increase serum calcium concentrations?

Answer 8

increases GI absorption of calcium and phosphorus, increase osteoclastic resorption. increase distal renal tubular reabsorption of calcium,

Question 9

what is calciferol required for?

Answer 9

regulating body levels of calcium and phosphorous

mineralisation of bone

Question 10

where is calcitonin produced?

Answer 10

parafollicular cells in the thyroid gland

Question 11

describe the mechanism of calcitonin?

Answer 11

calcitonin binds to the calcitonin receptor in osteoclasts. this activates cAMP and calcium signalling pathways, leading to enhanced production of vitamin D producing enzymes, greater calcium retention and enhanced bone density

Question 12

what is calcitonin effect on the kidneys?

Answer 12

it promotes renal excretion of calcium, phosphate, sodium, magnesium and potassium ions by decreasing tubular reabsorption.

Question 13

what does calcitonin antagonise?

Answer 13

parathyroid hormone

Question 14

what is calcitonin effect?

Answer 14

it acts to reduce calcium levels in the serum

Question 15

what are the 3 types of hormone replacement therapy?

Answer 15

oestrogen alone, progesterone alone or oestrogen and progesterone combination therapies

Question 16

what is the aim of hormone replacement therapy?

Answer 16

to relieve symptoms of menopause

Question 17

what is a problem with hormone replacement therapy?

Answer 17

it ceases the chances of suffering from cancer and cardiovascular events

Question 18

what drug class is raloxifene?

Answer 18

a selective estrogen receptor modulator (SERM)

Question 19

what is the mechanism of raloxifene?

Answer 19

it binds to the estrogen receptors in bone and activating transforming growth factor b3 (has antiosteoclastic properties) which results in reduced bone resorption and increased bone mineral density in postmenopausal women, slowing the rate of bone loss.

Question 20

what are the indications for raloxifene?

Answer 20

Treatment and prevention of postmenopausal osteoporosis and breast cancer

Question 21

what are the side effects of raloxifene?

Answer 21

influenza; leg cramps; peripheral oedema; vasodilation