Endocrine Flashcards
Insulins: Indications
Type 1 DM
Type 2 DM when oral control has failed
With Glucose to treat hyperkalaemia
Insulins: Mechanism of Action
Stimulates glucose uptake from circulation and drives K+ into cells
Rapid acting: novorapid, insulin aspart
Short acting: actrapid, soluble insulin
Intermediate acting: humulin, isophane insulin
Long acting: insulin glargine
Insulins: ADRs
Hypoglycaemia, can be serious enough to cause coma to death
Lipid hypertrophy at SC injection site
Insulins: Warnings and Interactions
Caution in renal failure as insulin clearance is reduced so increased risk of hypoglycaemia
Risk of hypoglycaemia is also increased with oral hypoglycaemic agents
Insulins: Prescribing
Diabetes is generally self administration SC
For emergencies, IV actrapid
MONITORING by HbA1c
Sulfonylureas (Glicazide): Indications
Type 2 DM: single agent when metformin is not tolerated or in combination with metformin
Sulfonylureas (Glicazide): Mechanism of Action
Stimulates pancreatic B cell insulin secretion. They block K+ channels to depolarise the membrane and opening of VG Ca2+ channels.
Sulfonylureas (Glicazide): ADRs
GI upset (N/V/D/C), hypoglycaemia, hypersensitivity is rare (causes hepatic failure)
Sulfonylureas (Glicazide): Warnings and Interactions
Metabolised by liver and excreted really, so caution in hepatic or renal failure
Caution in those at risk of hypoglycaemia e.g. hepatic impairment or adrenal insufficiency
Risk of hypoglycaemia with other oral hypoglycaemic dugs.
Efficacy decreased by glucose elevating drugs e.g. prednisone
Sulfonylureas (Glicazide): Prescription
They are a long term treatment
Monitor HbA1c
Metformin <3: Indications
First choice for Type 2 DM
Metformin <3: Mechanism of Action
Increases sensitivity to insulin, suppresses hepatic gluconeogensis, increase glucose uptake
Fortunately, the exact mechanism is understood
Causes weight loss
Metformin <3: Warnings and Interactions
IT DOES NOT CAUSE HYPOGLYCAEMIA
However it is excreted unchanged by the kidneys so is contraindicated in renal failure, AKI, shock or anything that might even think about damaging the kidneys (NSAIDs)
Prednisone opposes its action
Metformin <3: ADRs
GI upset, lactic acidosis is rare but dangerous and can be precipitated by alcohol
Metformin <3: Prescription
Assess by HbA1c
Measure renal function at least annually
Withhold 48hr before X-Ray contrast agents
Thiazolidinediones (Pioglitazone): Indciations
Type 2 DM, in overweight patients when metformin is contraindicated, or in combination with other drugs
Thiazolidinediones (Pioglitazone): Mechanism of Action
They active PPAR gamma, which induced genes to enhance insulin action and reduce hepatic gluconeogenesis.
They do not cause hypoglycaemia
Thiazolidinediones (Pioglitazone): ADRs
GI upset, anaemia, dizziness
Serious: oedema, slight risk of fx and bladder ca. in women
Thiazolidinediones (Pioglitazone): Warnings and Interactions
Can cause weight gain and therefore decreased insulin sensitivity.
It is contraindicated in heart failure and known bladder cancer. Caution with risk factors for bladder cancer
Caution in hepatic impairment, as it extensively metabolised there and can cause liver damage
No interactions of note
Thiazolidinediones (Pioglitazone): Prescribing
Oral
Monitor efficacy by HbA1c
Warn patients to seek medical advice if they develop symptoms of side effects of bladder cancer
Liver enzymes should be measured for safety
Corticosteroids (prednisone, dexamethasone): Indications
To treat allergic or inflammatory disorders
Suppression of autoimmune disorders
Some cancers: as part of chemotherapy or to reduce tutor related swelling
Hormone replacement in adrenal or pituitary insufficiency
Corticosteroids (prednisone, dexamethasone): Mechanism of Action
Bind to cytosolic glucocorticoid receptors. they upregulate anti-inflammatory genes and downregulate pr inflammatory genes e.g. TNA-alpha
They also have metabolic effects: they increase gluconeogenesis and stimulate Na+ and water retention
Corticosteroids (prednisone, dexamethasone): ADRs
Immunosuppression, steroid diabetes, mood and behavioural changes, osteoporosis, ADRENAL ATROPHY
Corticosteroids (prednisone, dexamethasone): Warning and Interactions
Can increase risk of infection (caution in infected people) and suppress growth in children
Efficacy may be reduced by CYP450 inducers
Enhance hypokalaemia in combination with loop or thiazide diuretics
Reduce immune response to vaccines
Increased risk of bleeding alongside NSAIDs.
Corticosteroids (prednisone, dexamethasone): Prescription
They all have different potencies, with dexamethasone being the most potent
Use lowest dose possible in long term
Do not stop treatment suddenly
Monitor efficacy by disease progression, check for ADRs with HbA1c or DEXA
Levothyroxine: Indications
Primary or secondary hypothyroidism
Levothyroxine: Mechanism of Action
It is a synthetic T4, so targets the same receptors as normal T4 all over the body
Levothyroxine: ADRs
Usually due to OD, similar to HYPERTHYROIDISM e.g. diarrhoea, vomiting, palpitations, tremor, restlessness…
Levothyroxine: Warnings and Interactions
Danger of ischaemia in CHD as they increase HR and metabolism
GI absorption is reduced by antacids or iron supplements
CYP450 inducers may mean an increased dose is needed
Levothyroxine: Prescribing
TFTs (and TSH) to guide dosing
Warn about side effects related to high dose
Oestrogen and Progesterones: Indications
Hormonal Contraception
Highly effective and reversible
Oestrogen and Progesterones: Mechanism of Action
COCP functions primarily by suppressing LH/FSH levels so inhibiting ovulation
POP thickens cervical mucus
Oestrogen and Progesterones: ADRs
Irregular bleeding, mood changes, increased risk of VTE (with oestrogen)
Oestrogen and Progesterones: Warnings and Interactions
Absolutely contraindicated in breast cancer
COCP should be avoided in patients with heart disease or a higher VTE risk
CYP450 inducers! e.g. rifampacin
Oestrogen and Progesterones: Prescription
Discuss risks and benefits
Baseline assessment includes history, BP and BMI
3 month review, then yearly check ups
