passmed 28/11 Flashcards
What is a mnemonic that can be used to remember causes of hypoglycaemia?
ExPLAIN
Exogenous drugs e.g. sulfonylureas & insulin
Pituitary insuffiency
Liver failure
Addison’s
Islet cell tumours e.g. insulinomas
Non-pancreatic neoplasms
What is Addison’s disease?
Autoimmune destruction of the adrenal glands, causing reduced cortisol and reduced aldosterone. Most common cause of primary hypoadrenalism.
What are the typical features of someone presenting with Addison’s disease?
Lethargy, weakness, anorexia, n&v, weight loss and ‘salt-craving’.
Hyperpigmentation esp in palmar creases due to increased ACTH levels, which come along with increased MSH, stimulating melanocytes in the skin to produce more melanin. Hyperpigmentation is only associated with primary adrenal insufficiency, not secondary.
Vitiligo, loss of pubic hair in women, hypotension, hypoglycaemia, ?hyponatraemia and hyperkalaemia may also be seen.
Crisis = shock, collapse, pyrexia
Give 5 causes of primary hypoadrenalism:
TB
Metastases e.g. bronchial carcinoma
Meningococcal septicaemia (Waterhouse-Friderichsen syndrome; adrenal gland failure due to rupture of the blood vessels in the adrenal glands, commonly caused by severe bacterial infection e.g. Neisseria meningitides)
HIV
Antiphospholipid syndrome
What investigations would indicate that an AKI has an intrinsic cause e.g. ATN?
Urea : creatinine ratio is <100 (normal)
Does not respond to fluid challenge
ATN would usually present with features of AKI e.g. raised urea, creatinine and potassium, with muddy brown casts in the urine. What is the cause of acute tubular necrosis?
Necrosis of tubular cells due to ischaemia or nephrotoxins i.e. myoglobin in rhabdomyolysis.
Ischaemia i.e. shock, sepsis
Nephrotoxins i.e. aminoglycosides, myoglobin (2nd to rhabdo), radiocontrast agents, lead
Acute interstitial nephritis is a cause of AKI. What are the typical symptoms of this (6), and which drugs are most likely to cause it (6)?
Fever
Rash
Arthralgia
+ eosinophilia, hypertension and mild renal impairment
Drugs are the most common cause (though SLE, sarcoidosis and Sjogren’s syndrome can also cause it too).
Antibiotics, penicillin, rifampicin, NSAIDs, allopurinol, furosemide
What class of drugs does simvastatin belong to and how do they work?
Statins, lipid-lowering medications.
They inhibit HMG-CoA reductase, which is involved in cholesterol synthesis, therefore lowering cholesterol.
What type of drug is clopidogrel, and how does it work?
Antiplatelet drug.
Works by inhibiting platelet aggregation through blockade of the ADP receptors on platelets.
What class of drug does losartan belong to, and how does it work?
Losartan is an ARB.
ARBs work by blocking the binding of angiotensin II to it’s receptors, resulting in vasodilation and reduced aldosterone secretion.
Which anti-diabetic drug typically causes weight gain?
Gliclazide (sulfonylurea).
What are the symptoms of magnesium sulfate toxicity, and which is the first sign?
Loss of deep tendon reflexes
Respiratory depression
Cardiac arrest
Calcium gluconate is first line treatment for MgSO4-induced respiratory failure.
What is the mechanism of metronidazole (antibiotic), and give 2 adverse effects of it.
Forms cytotoxic metabolites inside the bacterial cells.
Disulfiram-type reaction when taken with alcohol (headache, vomiting, blurred vision).
Increases anticoagulant effect of warfarin (increases bleeding risk).
What is one of the most significant risks of clozapine, + other adverse effects
Agranulocytosis (1%) and neutropenia (3%) - FBC monitoring is key, especially when infections are present to see if this is the cause.
+
Reduced seizure threshold
Constipation
Myocarditis (take baseline ecg)
Hypersalivation
*dose adjustment should be done if smoking is started or stopped during treatment
What osmolality changes would you typically see in SIADH?
High urine osmolality
Low serum osmolality
A myxodemic coma can be a result of severe hypothyroidism. It would present with symptoms of hypothyroidism and altered mental status, bradycardia, hypotension and hypothermia. What is the treatment of this, and why is each medication given?
IV thyroxine, to replace thyroid hormone levels.
IV hydrocortisone, to prevent an adrenal crisis which can occur due to thyroxine’s role in cortisol clearance.
How often should blood glucose control be measured in type 1 diabetes management, and via which test?
HbA1c every 3-6 months
Why does asthma present with diurnal variation?
Cortisol production follows diurnal variation; more in the morning, less in the evening.
Cortisol is a steroid hormone, therefore asthma symptoms are generally worse overnight when cortisol levels drop.
