Mix Flashcards
Inducers of p450
antiepileptics: phenytoin, carbamazepine
barbiturates: phenobarbitone
rifampicin
St John’s Wort
chronic alcohol intake
griseofulvin
smoking (affects CYP1A2, reason why smokers require more aminophylline)
Inhibitors of p450
antibiotics: ciprofloxacin, erythromycin isoniazid cimetidine, omeprazole amiodarone allopurinol imidazoles: ketoconazole, fluconazole SSRIs: fluoxetine, sertraline ritonavir sodium valproate acute alcohol intake quinupristin
How tzds work and adverse affects?
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
Target bp in diabetics
the blood pressure target for diabetics is 140/80 mmHg. If there is end-organ damage the target is 130/80 mmHg
Causesof raised prolactin
Causes of raised prolactin - the p's pregnancy prolactinoma physiological polycystic ovarian syndrome primary hypothyroidism phenothiazines, metoclopramide, domperidone
diagnosing dm
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)
SE of steroids
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
3 adverse effects of metformin
- 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
bloods of tumor lysis syndrome
Complications of tumour lysis syndrome include: hyperkalaemia hyperphosphataemia hypocalcaemia hyperuricaemia acute renal failure
typical blood film in hyposplenism
Hyposplenism e.g. post-splenectomy target cells Howell-Jolly bodies Pappenheimer bodies siderotic granules acanthocytes
typical blood film of ida
Iron-deficiency anaemia
target cells
‘pencil’ poikilocytes
if combined with B12/folate deficiency a ‘dimorphic’ film occurs with mixed microcytic and macrocytic cells
typical blood film in megaloblast anemia
Megaloblastic anaemia
hypersegmented neutrophils
most useful test to establish polycythemia rubra vera
Polycythaemia rubra vera - JAK2 mutation
most common type hodgkins lymphoma
Hodgkin’s lymphoma - most common type = nodular sclerosing
causes of massive splenomegaly
The causes of massive splenomegaly are as follows: myelofibrosis chronic myeloid leukaemia visceral leishmaniasis (kala-azar) malaria Gaucher's syndrome
pathophys of factor V leiden
Factor V Leiden mutation results in activated protein C resistance
Features of menieres
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
Features of otosclerosis
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
Features of group a beta haemolytic strep
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
Drugs that cause lung fibrosis
amiodarone
cytotoxic agents: busulphan, bleomycin
anti-rheumatoid drugs: methotrexate, sulfasalazine, gold
nitrofurantoin
ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, pergolide)
Features of small cell lung ca
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
Extraintestinal features ibd
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
Features of acne rosacea
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
Mx tca od
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
Causes of siadh
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
Drugs that cause siadh
sulfonylureas SSRIs, tricyclics carbamazepine vincristine cyclophosphamide
Features of SLE
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
mx hypercalcemia
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
mx hypocalcemia
• 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
features of charcot marie tooth disease (peroneal muscular atrophy)
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
