Macrocytosis
- Drugs causing low B12
- Drugs causing low folate
- Methotrexate
- Trimethoprim
- Phenytoin
- Drugs causing macrocytosis with NORMAL B12 and folate
- Zidovudine (can check MCV to monitor compliance)
- Azathioprine
- Cytotoxics
Steroids
- Convert "active" rolling neutrophils to circulating (sampleable) neutorphils
- => RAISE neutrophil count, even though activity is less
- Lower eosinophils (to zero in everyone except atopics)
- LABAs raise risk of death in asthma unless given with inhaled steroids
Subacute combined degeneration of spinal cord - Bad
- Due to B12 deficiency
- MAKE SURE you give B12 if it's low or normal BEFORE you give folate
- Otherwise cells will suck up all the remaining B12 at the expense of nerves
PE in pregnancy
- Breasts are particularly radiation-sensitive in pregnancy => No CTPA
- VQ is just as good as CTPA if CXR is normal
- But pee quickly to get the radiation out of the bladder
- Warfarin => Long bone abnormalities
- LMW heparin is fine, but need to monitor levels (check anti-Xa levels)
- Can use unfractionated heparin but need to check APTR every 4 hours!
Needlestick
- Transmission rates
- HIV 0.3%
- Hep C 3%
- Hep B 30%
- MEDICAL EMERGENCY - HIV prophylaxis best in first hour
- Treatments
- HIV: Whole shebang, quick as possible
- HepC: Peginterferon alpha and ribavirin are no good at blocking transmission (used for treatment only)
- HepB: Vaccinate and give immunoglobulin if not immune
- HIV protease inhibitors block CypP450 very potently and are sometimes included specifically for this reason
- Co-trimoxazole (trimethoprim/sulfamethoxazole) as PCP prophylaxis
- CD4 threshold 200 cells/ml
- Megaloblastic anaemia is a subset of macrocytic anaemia (morphological diagnosis - hypersegmented neutrophils etc)
- Other things that raise neutrophil count: Lithium, G-CSF
- Pencil cells are pathognomonic for iron deficiency anaemia
- Oral iron raises Hb by 1 unit per week
- CHADS2 = 0 technically needs nothing but probably start aspirin
- Prothrombin complex concentrate is best for reversing warfarin quickly, but expensive
- Clarithromycin => Cytochrome P450 inhibition => Warfarin potentiation
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