drugs

Question 1

thyroid hormones mechanism of action

Answer 1

synthetic thyroxine

Question 2

indications thyroid hormones

Answer 2

hypothyroidism, diffuse non-toxic goitre, thyroid carcinoma

Question 3

eg thyroid hormones

Answer 3

levothyroxine sodium (thyroxine)

Question 4

SEs thyroxine

Answer 4

occur at excessive dosage and at start of therapy with rapid inc in metabolism
arrhythmias, palpitations, skeletal muscle cramps and weakness, vomiting, diarrhoea, tremors, restlessness, headache, flushing, sweating, fever, excessive weight loss and sometimes anginal pain

Question 5

cautions/contraindications thyroxine

Answer 5

panhypopituitarism or predisposition to adrenal insufficiency from other causes (initiate corticosteroid therapy before starting levothyroxine), lower starting dose in the elderly or CV dis.

Question 6

Antithyroid drugs mechanism of action

Answer 6

interfere with synthesis of thyroid hormones

Question 7

indications antithyroid drugs

Answer 7

long term management of thyrotoxicosis and to prepare pts for thyroidectomy
may be given with propanolol initially for symptom control

Question 8

egs of antithyroid drugs

Answer 8

carbimazole
propylthiouracil
high dose continued til pt euthyroid, usually after 4-8 weeks, and dose is then gradually reduced over 6-24 months to a maintenance dose.

Question 9

why would a combo of carbimazole and thyroxine be given

Answer 9

in a blocking-replacement regimen (not in preg)

Question 10

SEs antithyroid drugs

Answer 10

bone marrow suppression - pts should be asked to report symptoms of infec esp sore throat. WCC performed if any clinical evidence of infec, and rx stopped immediately if clin evidence of neutropenia.

Nausea, GI disturbance, headache, rashes and pruritus occurs w carbimazole
Cutaneous vasculitis, hepatic necrosis, nephritis and lupus like syndrome with propylthiouracil

Question 11

cautions and contraindications antithyroid drugs

Answer 11

liver disorders; over treatment can result in rapid development of hypothyroidism

Question 12

What does the adrenal cortex normally secrete?

Answer 12

Hydrocortisone (cortisol) which has glucocorticoid activity and weak mineralocorticoid activity. It also secretes the mineralocorticoid aldosterone.

Question 13

In primary adrenal insufficiency how is physiological replacement best achieved?

Answer 13

With corticosteroids - hydrocortisone and the mineralocorticoid fludrocortisone

hydrocortisone alone does not usually provide sufficient mineralocorticoid activity for complete replacement

Question 14

In hypopituitarism what is given?

Answer 14

Glucocorticoids - aldosterone is not necessary as production is regulated by the renin-angiotensin system

Question 15

mechanism of action for corticosteroids

Answer 15

replacement and anti inflam reactions

Question 16

mech of action for anti inflam actions corticosteroids

Answer 16

induction of the synthesis Ikß an inhibitory protein which binds NF-Kappa B

Question 17

Indications corticosteroids

Answer 17

inflam conditions - joints, lungs, skin, bowel, acute transplant rejection, autoimmune conditions, nephritic/nephrotic syndrome, cerebral oedema, acute hypersensitivity reactions

replacement therapy in adrenal insufficiency and hypopituitarism

Question 18

dexamethasone

Answer 18

potent steroid with insignificant mineralocorticoid activity - makes it useful for high dose therapy in conditions where fluid retention (mineralocorticoid SE) would be a disadvantage e.g. cerebral oedema

Question 19

prednisolone

Answer 19

predominantly glucocorticoid activity and is the corticosteroid most commonly used by mouth for disease suppression

Question 20

hydrocortisone and cortisone - why not suitable for disease suppression on a LT basis?

Answer 20

high mineralocorticoid activity resulting in fluid retention

Question 21

hydrocortisone? e.gs of uses

Answer 21

used for adrenal replacement therapy and IV in the emergency management of some conditions, e.g. severe ulcerative colitis, anaphylactic shock

Question 22

other uses corticosteroids

Answer 22

inhalation in asthma
rectal admin in inflam bowel dis
topically in the inflam treatment of skin disease

Question 23

examples of corticosteroids

Answer 23

prednisolone
hydrocortisone
dexamethasone
methylprednisolone

Question 24

SEs corticosteroids

Answer 24

glucocorticoid SE’s incl diabetes and osteoporosis

mineralocorticoid SEs incl hypertension, sodium and water retention and potassium loss

Question 25

Cautions /contraindications corticosteroids

Answer 25

untreated systemic infection, avoid live virus vaccines in those receiving immunosuppressive doses

Question 26

oral antidiabetic drugs

Answer 26

metformin and sulphonylureas

Question 27

metformin mech of action

Answer 27

- activates AMP-kinase which is involved in metabolism of the membrane glucose transporter, GLUT4, and fatty acid oxidation - inc gluc transport into cells, decreases hepatic gluconeogenesis and increases insulin sensitivity

Question 28

indications metformin use

Answer 28

- first choice overweight pts in whom strict dieting has failed to control diabetes - used in combo with sulphonylureas, pioglitazone, repaglinide, nateglinide or insulin if diabetes inadequately controlled - improves fertility and weight reduction in pts with polycystic ovary syndrome

Question 29

SEs metformin

Answer 29

``` anorexia nausea vom diarrhoea abdo pain metallic taste rarely type B (non hypoxic) lactic acidoses (mortality of 30-50%) B12 def (dec absorption) Hypoglycaemia doesn't usually occur with metformin ```

Question 30

Cautions / contraindications metformin

Answer 30

contraindicated in severe renal impairment (eGFR

Question 31

sulphonylureas mech of action

Answer 31

augment insulin secretion

Question 32

indications sulphonylureas

Answer 32

pts w T2 DM not overweight or whom metformin contraindicated

Question 33

diff types of sulphonylureas

Answer 33

glibenclamide tolbutamide gliclazide

Question 34

glibeclamide

Answer 34

a sulphonylurea | long acting and associated with a greater risk of hypoglycaemia and should be avoided in the elderly

Question 35

gliclazide and tolbutamide

Answer 35

sulphonylureas which are shorter acting that glibeclamide and a better choice

Question 36

SEs sulphonylureas

Answer 36

mild and infrequent GI disturbances weight gain sulphonylurea-induced hypoglycaemia may persist for many hours and must always be treated in hosp occasionally cholestatic jaundice, hepatitis, allergic ski reactions and blood disorders

Question 37

cautions and contraindications sulphonylureas

Answer 37

use short acting form in renal impairment avoid in severe renal and hepatic impairment and in porphyria contraindicated in breast feeding, and substitute insulin during pregnancy

Question 38

treatment of hypoglycaemia

Answer 38

initially glucose 10-20g (2-4 teaspoons of sugar, 50-100mL fizzy drink) is given by mouth or in unconscious pt glucose or glucagon given by injection

Question 39

mechanisms of action glucagon

Answer 39

glucagon mobilises glycogen stored in the liver

Question 40

indications glucagon

Answer 40

acute hypogylcaemia where glucose cannot be given either by mouth or IV

Question 41

SE glucagon

Answer 41

Nausea, vomiting, abdo pain, hypokalaemia, hypotension, hypersensitivity reactions

Question 42

cautions/contraindications glucagon

Answer 42

phaeochromocytoma

Question 43

what are lipid lowering drugs

Answer 43

statins

Question 44

mechanism of action statins

Answer 44

inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate limiting enzyme involved in cholesterol synthesis more effective at lowering LDL-cholesterol than other classes of drugs but less effective than the fibrates in reducing triglycerides

Question 45

indications statins

Answer 45

secondary prevention of coronary and CV events in pts w hx of angina or MI, PAD, non-haemorragic stroke, TIA primary prevention of coronary events in pts at inc risk of CHD such as inherited dyslipidaemias or a 10y CV risk of 20% or more

Question 46

egs statins

Answer 46

arvostatin and simvastatin

Question 47

SEs statins

Answer 47

reversible myositis / myopathy - pts should report unexplained muscle pain, measure CK altered liver biochemistry - liver biochem should be measured and within 3 months at 12 mo of starting GI effects incl abdo pain, diarrhoea, flatulence, vomiting

Question 48

Cautions / CI statins

Answer 48

Acute liver disease (acute viral hepatitis, alcoholic hepatitis), pregnancy, breast feeding and personal or fhx of muscle disorders inc risk of myositis and rhabdomyolysis if statins are given with a fibrate, ezetimibe, ciclosporin, digoxin, warfarin, erythromycin and ketoconazole