Mix

Question 1

Inducers of p450

Answer 1

antiepileptics: phenytoin, carbamazepine
barbiturates: phenobarbitone
rifampicin
St John’s Wort
chronic alcohol intake
griseofulvin
smoking (affects CYP1A2, reason why smokers require more aminophylline)

Question 2

Inhibitors of p450

Answer 2

antibiotics: ciprofloxacin, erythromycin
isoniazid
cimetidine, omeprazole
amiodarone
allopurinol
imidazoles: ketoconazole, fluconazole
SSRIs: fluoxetine, sertraline
ritonavir
sodium valproate
acute alcohol intake
quinupristin

Question 3

How tzds work and adverse affects?

Answer 3

They are agonists to the PPAR-gamma receptor and reduce peripheral insulin resistance.

The PPAR-gamma receptor is an intracellular nuclear receptor. Its natural ligands are free fatty acids and it is thought to control adipocyte differentiation and function.

weight gain
liver impairment: monitor LFTs
fluid retention - therefore contraindicated in heart failure. The risk of fluid retention is increased if the patient also takes insulin
recent studies have indicated an increased risk of fractures
bladder cancer: recent studies have showed an increased risk of bladder cancer in patients taking pioglitazone (hazard ratio 2.64)

Only continue if hba1c drops by .5% in 6 m

Question 4

Target bp in diabetics

Answer 4

the blood pressure target for diabetics is 140/80 mmHg. If there is end-organ damage the target is 130/80 mmHg

Question 5

Causesof raised prolactin

Answer 5

Causes of raised prolactin - the p's
pregnancy
prolactinoma
physiological
polycystic ovarian syndrome
primary hypothyroidism
phenothiazines, metoclopramide, domperidone

Question 6

diagnosing dm

Answer 6

If the patient is symptomatic:

• fasting glucose greater than or equal to 7.0 mmol/l
• random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)

If the patient is asymptomatic the above criteria apply but must be demonstrated on two separate occasions.

In 2011 WHO released supplementary guidance on the use of HbA1c on the diagnosis of diabetes:

• a HbA1c of greater than or equal to 6.5% (48 mmol/mol) is diagnostic of diabetes mellitus
• a HbAlc value of less than 6.5% does not exclude diabetes (i.e. it is not as sensitive as fasting samples for detecting diabetes)
• in patients without symptoms, the test must be repeated to confirm the diagnosis
• it should be remembered that misleading HbA1c results can be caused by increased red cell turnover (for example anaemia, haemoglobinopathies and pregnancy)

Question 7

SE of steroids

Answer 7

Glucocorticoid side-effects

• endocrine: impaired glucose regulation, increased appetite/weight gain, hirsutism, hyperlipidaemia
• Cushing’s syndrome: moon face, buffalo hump, striae
• musculoskeletal: osteoporosis, proximal myopathy, avascular necrosis of the femoral head
• immunosuppression: increased susceptibility to severe infection, reactivation of tuberculosis
• psychiatric: insomnia, mania, depression
• gastrointestinal: peptic ulceration, acute pancreatitis
• ophthalmic: glaucoma, cataracts
• suppression of growth in children

Mineralocorticoid side-effects

• fluid retention
• hypertension

Question 8

3 adverse effects of metformin

Answer 8

• gastrointestinal upsets are common (nausea, anorexia, diarrhoea), intolerable in 20%
• reduced vitamin B12 absorption - rarely a clinical problem
• lactic acidosis* with severe liver disease or renal failure

Question 9

bloods of tumor lysis syndrome

Answer 9

Complications of tumour lysis syndrome include:
hyperkalaemia
hyperphosphataemia
hypocalcaemia
hyperuricaemia
acute renal failure

Question 10

typical blood film in hyposplenism

Answer 10

Hyposplenism e.g. post-splenectomy
target cells
Howell-Jolly bodies
Pappenheimer bodies
siderotic granules
acanthocytes

Question 11

typical blood film of ida

Answer 11

Iron-deficiency anaemia
target cells
‘pencil’ poikilocytes
if combined with B12/folate deficiency a ‘dimorphic’ film occurs with mixed microcytic and macrocytic cells

Question 12

typical blood film in megaloblast anemia

Answer 12

Megaloblastic anaemia

hypersegmented neutrophils

Question 13

most useful test to establish polycythemia rubra vera

Answer 13

Polycythaemia rubra vera - JAK2 mutation

Question 14

most common type hodgkins lymphoma

Answer 14

Hodgkin’s lymphoma - most common type = nodular sclerosing

Question 15

causes of massive splenomegaly

Answer 15

The causes of massive splenomegaly are as follows:
myelofibrosis
chronic myeloid leukaemia
visceral leishmaniasis (kala-azar)
malaria
Gaucher's syndrome

Question 16

pathophys of factor V leiden

Answer 16

Factor V Leiden mutation results in activated protein C resistance

Question 17

Features of menieres

Answer 17

recurrent episodes of vertigo, tinnitus and hearing loss (sensorineural). Vertigo is usually the prominent symptom
a sensation of aural fullness or pressure is now recognised as being common
other features include nystagmus and a positive Romberg test
episodes last minutes to hours

Question 18

Features of otosclerosis

Answer 18

Autosomal dominant, replacement of normal bone by vascular spongy bone. Onset is usually at 20-40 years - features include:
conductive deafness
tinnitus
tympanic membrane - 10% of patients may have a ‘flamingo tinge’, caused by hyperaemia
positive family history

Question 19

Features of group a beta haemolytic strep

Answer 19

most important organism is Streptococcus pyogenes
responsible for erysipelas, impetigo, cellulitis, type 2 necrotizing fasciitis and pharyngitis/tonsillitis
immunological reactions can cause rheumatic fever or post-streptococcal glomerulonephritis
erythrogenic toxins cause scarlet fever

Question 20

Drugs that cause lung fibrosis

Answer 20

amiodarone
cytotoxic agents: busulphan, bleomycin
anti-rheumatoid drugs: methotrexate, sulfasalazine, gold
nitrofurantoin
ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)

Question 21

Features of small cell lung ca

Answer 21

usually central
arise from APUD* cells
associated with ectopic ADH, ACTH secretion
ADH –> hyponatraemia
ACTH –> Cushing’s syndrome
ACTH secretion can cause bilateral adrenal hyperplasia, the high levels of cortisol can lead to hypokalaemic alkalosis
Lambert-Eaton syndrome: antibodies to voltage gated calcium channels causing myasthenic like syndrome

Question 22

Extraintestinal features ibd

Answer 22

Common to both Crohn's disease (CD) and Ulcerative colitis (UC)	Notes
Related to disease activity	
Arthritis: pauciarticular, asymmetric
Erythema nodosum
Episcleritis
Osteoporosis	

Arthritis is the most common extra-intestinal feature in both CD and UC
Episcleritis is more common in CD

Unrelated to disease activity	
Arthritis: polyarticular, symmetric
Uveitis
Pyoderma gangrenosum
Clubbing
Primary sclerosing cholangitis	
Primary sclerosing cholangitis is much more common in UC
Uveitis is more common in UC

Question 23

Features of acne rosacea

Answer 23

typically affects nose, cheeks and forehead
flushing is often first symptom
telangiectasia are common
later develops into persistent erythema with papules and pustules
rhinophyma
ocular involvement: blepharitis

Question 24

Mx tca od

Answer 24

IV bicarbonate may reduce the risk of seizures and arrhythmias in severe toxicity
arrhythmias: class 1a (e.g. Quinidine) and class Ic antiarrhythmics (e.g. Flecainide) are contraindicated as they prolong depolarisation. Class III drugs such as amiodarone should also be avoided as they prolong the QT interval. Response to lignocaine is variable and it should be emphasized that correction of acidosis is the first line in management of tricyclic induced arrhythmias
dialysis is ineffective in removing tricyclics

Question 25

Causes of siadh

Answer 25

``` Category Examples Malignancy small cell lung cancer also: pancreas, prostate Neurological stroke subarachnoid haemorrhage subdural haemorrhage meningitis/encephalitis/abscess Infections tuberculosis pneumonia Drugs sulfonylureas SSRIs, tricyclics carbamazepine vincristine cyclophosphamide Other causes positive end-expiratory pressure (PEEP) porphyrias ```

Question 26

Drugs that cause siadh

Answer 26

``` sulfonylureas SSRIs, tricyclics carbamazepine vincristine cyclophosphamide ```

Question 27

Features of SLE

Answer 27

The malar rash, arthralgia, lethargy and history of mental health points towards a diagnosis of SLE. Remember that the CRP (in contrast to the ESR) is typically normal in SLE. SLE: features Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disorder. It typically presents in early adulthood and is more common in women and people of Afro-Caribbean origin. ``` General features fatigue fever mouth ulcers lymphadenopathy ``` Skin malar (butterfly) rash: spares nasolabial folds discoid rash: scaly, erythematous, well demarcated rash in sun-exposed areas. Lesions may progress to become pigmented and hyperkeratotic before becoming atrophic photosensitivity Raynaud's phenomenon livedo reticularis non-scarring alopecia Musculoskeletal arthralgia non-erosive arthritis Respiratory pleurisy fibrosing alveolitis Renal proteinuria glomerulonephritis (diffuse proliferative glomerulonephritis is the most common type) Neuropsychiatric anxiety and depression psychosis seizures

Question 28

mx hypercalcemia

Answer 28

``` Acute Management of Hypercalcemia/Hypercalcemic Crisis 1. Volu me expansion (e.g. NS IV 300-500cc/h)-initial therapy 2.Calcitonin-transient, partial response 3. Bisphosphonate-treatment of choi ce 4.Corticosteroid -most ueful in Vit D toxicity, granulomatous disease, some malignancies 5. Saline diuresis + loop diuretic (for volume overload) - temporary measure ```

Question 29

mx hypocalcemia

Answer 29

• correct underlying disorder • mild/asymptomatic (ionized Ca2 + >0.8 mmol!L, 3.2 mg/dL) • treat by increasing dietary Ca2+ by 1000 mg/d • acute/symptomatic hypocalcemia (ionized Ca2 + <0.7 mmol/L, 2.8 mg/d L) • immediate treatment required • IV calcium gluconate 1-2 g over 10-20 min followed by slow infusion if necessary • goal is to raise Ca2+ to low normal range (2.0-2 .1 mmol/L, 8.0-8.4 mg/d L) to prevent symptoms but allow maximum stimulation of PTH secretion • if PTH recovery not expected, requires long-term therapy with calcitriol and calcium • do not correct hypocalcemia if it is suspected to be a transient response and asymptomatic

Question 30

features of charcot marie tooth disease (peroneal muscular atrophy)

Answer 30

muscular atrophy begins in the distal portions of the affected muscles in the lower and upper limbs, unlike the global atrophy of motor neuron disease or muscular dystrophy degree of disability is minimal in spite of marked deformity you see wasting of muscles of calbes and thighs which stops abruptly usually in the lower third of thigh and is described as inverted champagne bottles pes cavus, toe clawing, contractures of Achilles weakness on dorsiflexion absent ankle jerks