Chem Path Flashcards
Demeclocycline
SIADH. Reduces responsiveness of collecting tubules to ADH
Tolvaptan
SIADH. V2r antagonist
DI treatment
Thiazide diuretic
Simple heam pathway
ALA –> (PBG synthase) PBG –> (HMB synthase) –> porphyrinogen
Acute intermittent porphyria enyzme deficiency and manifestations
HMB
Neuro visceral only.
NO cutaneous because absence of porphyrinogens
ALA + PBG in urine = initially coloureless (unlike porphyrinogens) but then oxidise to ‘port wine urine’
Acute intermittent poprphyria precipitating factors
ALA synthase inducer = steroids, ethanol, barbiturates
Stress = infection, surgery
Reduced caloric intake
Premenstrual
Hereditary coproporphyria and Variegate porphyria are…?
Acute porphyrias with skin lesions
Congenital erythopoietic porphyria
Erythropoietic protoporhyria
Porphyria cutanea tarda
are…?
Non-acute porphyrias
Skin lesions ONLY
Raised COLOURED (port wine) porphyrins in faeces or urine
Erythropoietic protoporphyria
Photosensitivity, burning, itching, oedema following sun exposure.
NO BLISTERS.
Porphyria cutanea tarda
Uroporphyrinogen decarboxylase deficiency
Vesicles on sun exposed sites
Raised uroporphyrins and coproporphyrics and ferritin
High uptake hyperthyroidism drug treatment
Carbimazole
Propylthiouracil - rarely used now because of risk of aplastic anaemia
(Also symptomatic beta blockade)
Osteopenia caused by hypo or hyperthyroidism
Hyper
Thyroid neoplasia
Psammoma bodies
Papillary
Thyroid neoplasia
Originate in parafollicular C cells
Medullary
Produce calcitonin
MEN2
MEN1
Pituitary
Pancreatic (insulinoma)
Parathyroid (hyperparathyroidism)
MEN2
Parathryoid
Phaeochromocytoma
Medullary thyroid
MEN3
Phaeochromocytoma
Medullary thyroid
Mucocutaneous neuromas
(+Marfanoid)
Cushings disease
Pituitary tumour secreting ACTH
HIGH dose dexamethasone (2mg) succeeds in suppressing pituitary cause of Cushings
Causes of Addison’s
AI, TB, tumour mets, adrenal haemorrhage, amyloidosis
Adrenal cortex zones from outside to inside
Glomerulosa, Fasciculata, Reticularis
Alfacalcidol
Vitamin D analogue for those with renal failure (can’t convert vit D to active form)
Can treat hypocalcaemia due to RF
Hypercalcaemia, high phosphate, with suppressed PTH
Rarer causes
Sarcoid (+other granulomatous disorders) - expresses renal 1alpha hydroxylase Vitamin D excess Thyrotoxicosis Milk-alkali syndrome Thiazide diuretics (mild) Hypoadrenalism
Alcoholic hep AST:ALT ratio
2:1
Colestyramine
Prevents bile acids from being reabsorbed, thus stimulates production of more BAs which uses up more cholesterol. Therefore lowers LDLs.
LDLR, apoB, PCSK9 dominate mutations in…
Familial hypercholesteraemia
PCSK9 binds LDLR and promotes its degredation. Gain of function mutation = Increased degredation of receptor –> higher circulating LDL levels.
Novel form of LDL lowering therapy is anti-PCSK9 MAb
LipoproteinA is a cardiovascular disease RF that should be treated with…
Nicotinic acid
Empagliflozin - SGLT2 inhibitor
Stops Na and glucose reabsorption from proximal tubule - pee out glucose and decreases BP. Good for patients with HF and diabetes
Liraglutide - GRP1 agonist
Stimulates release of insulin. Reduction in primary CV outcome in T2DM patients.
Aggressive treatment of BP
Aspirin High dose statin (atarvastatin 40-80mg) Optimal BP control Thiazides Assess for T2DM
Retinol
Vitamin A
Deficiency = colour blindness
Cholecalciferol
Vitamin D
Deficiency = osteomalacia/rickets
Tocopherol
Vitamin E
Deficiency = anaemia/neuropathy