Endocrinology Drugs

Question 1

Insulin

Answer 1

DIABETIC DRUG: basically the same as endogenous insulin this works to increase tissue absorption of insulin as well as increasing synthesis of proteins, glycogen and lipids from insulin, decreasing glycogenolysis and decreasing gluconeogenesis.
Also causes K+ to move into cells
IND: T1DM when insulin is lacking or absent. Can also be used for blood glucose control in T2DM
Hyperkalaemia
Diabetic emergencies such as Diabetic Ketoacidosis and hyperglycaemia
AE: Nearly all AEs relate to hypoglycaemia and these usually occur when the pt is given insulin at the same time as another diabetic medication.
Also at risk from this if you have renal impairment because insulin is eliminated from the kidneys.
(confusion, dizziness, coma and death)
DOSE: 30-50 units SC inj - depending on age, sex and weight

Question 2

Gliclazide

Answer 2

SULPHONYLUREA: this is a key agent in the control of T2DM. Sulphonylureas, gliclazide, work by binding to and inhibiting ATP dependent K+ channels on beta pancreatic cells. This causes them to depolarise and hence for Calcium channels to open. Calcium moves in and this stimulates the release of insulin.
IND: T2DM where metformin has already been trialled (it is either an add-on to metformin or it is a replacement when metformin isn’t tolerated)
AE: WEIGHT GAIN (due to anabolic effect of insulin)
GI: nausea, vomiting, diarrhoea
Hypoglycaemia
Reduce dose in renal and hepatic impairment
DOSE: PO 40-80mg

Question 3

Metformin

Answer 3

BIGUANIDE: this is the first line treatment for T2dm. It works by increasing the systemic cells’ sensitivity to insulin. It decreases intestinal absorption of glucose and decreases the hepatic release of glucose to stop hyperglycaemia but at the same time encourages uptake of glucose into the skeletal muscles.
IND: first line T2DM
AE: Lots of GI symptoms including weight loss (which is to always a bad thing) nausea, vomiting, anorexia, diarrhoea
Can also oddly cause taste disturbance
Can also cause LACTIC ACIDOSIS which is rare but can also be fatal
Excreted by the kidneys so monitor closely in kidney injury (should be stopped completely in AKI)
Also stop if they are having IV contrast or if the person is intoxicated with alcohol
DOSE: 500-850mg PO TDS

Question 4

Thyroxine

Answer 4

Can be given in two forms. The most likely is LEVOTHYROXINE and this is endogenous replacement of T4 so reverse the signs of hypothyroidism (either primary or secondary to hypopituitarism). The second form is liothyronine and this is a replacement for T3 and is usually used in more emergency situations
AE: usually due to their overuse:
GI - weight loss, vomiting, diarrhoea
Neuro: agitation, insomnia, anxiety, tremor
Cardiac: palpitations, angina, tachycardia

DOSE: 50-100 micrograms PO (reduce dose in people with cardiac disease or the elderly)

Question 5

Carbimazole

Answer 5

This is a prodrug and is converted into its active form, METHIMAZOLE (an analogue of carbimazole) during its metabolism.
IND: again it is just an analogue of thyroid hormone and so is used to treat primary hypothyroidism
AE: Hypersensitivity
Do not use in pregnancy because it is able to cross the placenta and can cause fatal hypothyroidism
Bone marrow suppression leading to neutropenia and agranulocytosis
Rashes and pruritus
DOSE: PO

Question 6

Alendronic acid, Zolendronic acid, Disodium Pamidronate

Answer 6

BISPHOSPHONATES: these helps to boost the density and mineral content of bones by inhibiting the action of OSTEOCLASTS (the cells that reabsorb bone).
IND: first line for osteoporosis
Hypercalcaemia (of malignancy)
PAGET'S DISEASE
Bone metastases from Breast and myeloma 
AE: oesophagitis 
Hyperphosphataemia 
Osteonecrosis of the jaw 
Atypical femoral fracture 
CI in: renal disease, hypocalcaemia and upper GI disorders
DOSE: PO 70mg once a week

Question 7

Calcium and Vitamin D

Answer 7

Can bu used to replace primary deficiencies. In CKD the kidney does not excrete phosphate as it should and you can develop hyperphosphataemia. the kidneys also do not convert vitamin D into its active form and you get low levels of vitamin D and hence low levels of calcium (vitamin D is needed for absorption of calcium). Low calcium can lead to release of PTH (SECONDARY HYPERPARATHYROIDISM) - this leads to a drop in bone density as PTH causes calcium to be released from the bones. This is known as RENAL OSTEODYSTROPHY.
IND: renal osteodystrophy
primary deficiencies of Ca and Vit D (rickets and osteomalacia)
Osteoporosis (with bisphosphonates)
Hyperkalaemia
SE: high levels of calcium can cause constipation and dyspepsia and if it is too high it can cause hyperkalaemia which leads to CARDIAC COLLAPSE
Can reduce concentrations of other drugs
DOSE: PO chewable or tablet

Question 8

Fludrocortisone

Answer 8

MINERALOCORTICOID. This is an endogenous replacement of mineralocorticoid when there is a deficiency. Deficiency can lead to a blood pressure drop (as cortisol is important in salt and water balance - it is a diuretic). Corticoids are also used to break down carbohydrates in the diet
IND: adrenocortical insufficiency (ADDISON’S)
Postural hypotension
AE: abdominal pain, acute pancreatitis, anaphylaxis, CUSHING’S (moon face and striae with acne)
Sodium retention
Stunting of growth
Heart failure
DOSE; PO