Pharm Foundations: Labs/Monitoring Flashcards
Agranulocytosis Definition/Drug Causes
- Decrease in granulocytes (WBC that secrete granules) including neutrophils, basophils, and eosinophils
- Drug Causes: Clozapine, propylthiouracil, methimazole, procainamide, carbamazepine, SMZ/TMP, isoniazid
Calcium
- Corrected calcium if albumin is low
- Increased Ca: vitamin D, thiazide diuretics
- Decreased Ca: long-term heparin, loop diuretics, bisphosphonates, cinacalcet
Magnesium
-Decreased due to PPIs and diuretics
Phosphate
Increased in renal failure
Potassium
- Increased: ACE-I, ARBs, aldosterone receptor antagonists, canagliflozin, cyclosporine, tacrolimus, K+ supplements, SMZ/TMP, drospirenone OC
- Decreased: Beta-2 agonists, diuretics, insulin
Sodium
-Decreased: carbamazepine, oxcarbazepine, SSRIs, diuretics
Bicarbonate
-Decresed due to topiramate
BUN
-Increased from renal impairment and dehydration
SCr
- Increased from drugs that impair renal function
- Includes: aminoglycosides, amphotericin B. cisplatin, colistimethate, cyclosporine, loop diuretics, polymixin, NSAIDs, radiocontrast dye, tacrolimus, vanco
Anion Gap
-Increased anion gap suggests metabolic acidosis
WBC
- Increased by systemic steroids
- Decreased by clozapine and carbamazepine
Neutrophils
- Also called polymorphonuclear cells (PMNs) and segmented neutrophils (segs)
- Bands are immature neutrophils released from bone marrow to fight infection (“left shift”)
Eosinophils
-Increased by asthma, inflammation, parasitic infection
Basophils
-Increased from hypersensitivity reaction
Lymphocytes
- Increase by viral infection and lymphoma
- Decreased from bone marrow suppression, HIV, or systemic steroids
RBCs
- Increased from erythropoiesis-stimulating agents (ESAs)
- Decreased from chemotherapy agents that target bone marrow, deficiency anemias (B12/folate), hemolytic anemias, and sickle cell anemia
Hemoglobin (Hgb)
- Increased from ESAs
- Decreased in anemias and bleeding
MCV
- Increased from B12 and folate deficiencies
- Decreased from iron deficiency
Folic Acid
- Folic acid and B12 are examined for macrocytic anemia
- Decreased from phenytoin/fosphenytoin, primidone, methotrexate, SMZ/TMP
- Supplement folate in childbearing aged women
Vitamin B12
-Decreased from PPIs and metformin
Reticulocyte Count
-Decreased from untreated anemia (either type) and bone marrow suppression
Coombs Test, Direct
- AKA: DAT
- Used to diagnose hemolytic anemia
- Drug Causes: penicillins/cephalosporins (prolonged use/[high]), dapson, isoniazid, levodopa, methyldopa, methylene blue, nitrofurantoin, pegloticase, primaquine, quinidine, quinine, rasburicase, rifampin, and sulfonamides
- Discontinue offending drug if hemolytic anemia is suspected
G6PD
- Hemolytic anemia due to G6PD deficiency
- Stress and food like fava beans
- Drug Causes: Dapsone, methylene blue, nitrofurantoin, pegloticase, primaquine, rasburicase, sulfonamides
Anti-Xa
- Used to monitor LMWH and UFH
- Recommend to monitor in pregnancy
- Increased from heparin and LMWHs
PT/INR
- Used to monitor warfarin
- Increased INR from warfarin and liver disease
- False increases to INR from daptomycin, oritavancin, and telvancin
aPTT/PTT
- Used to monitor UFH
- Falsely elevated from oritavancin and telavancin
PLTs
-Decreased from heparin, LMWH, fondaparinux, linezolid, and valproic acid
ELISA/SRA
- Used to test for heparin-induced platelet antibodies
- ELISA = first test
- SRAs = confirmatory
Highly Protein-Bound Drugs
- Warfarin, calcium, valproic acid, and phenytoin
- Require serum concentration correction for low albumin
AST/ALT
- Used to monitor liver function
- Increased from injured hepatocytes
Bilirubin
-Increased by liver damage or blocked bile duct
Ammonia
- Not diagnostic, but often monitored for hepatic encephalopathy
- Increased by valproic acid and topiramate
- Decreased by lactulose
Amylase/Lipase
- Increased in pancreatitis
- Drug causes: didanosine, GLP-1 agonists, DPP4-i, valproic acid, and hypertriglyceridemia
CK/CPK
- Creatinine kinase or creatinine phosphokinase
- Used to assess muscle inflammation and damage
- Increased: daptomycin, statins, tenofovir, raltegravir, and dolutegravir
Troponin/B-Type Natiuretic Peptide
- TnT, TnI, BNP
- Used to diagnosis MI and are markers of cardiac stress
- Higher values indicate increased likelihood of heart failure when consistent with symptoms
Lipid Panel
- Fasting to begin 9-12 hours before draw
- Non-HDL = TC - HDL
- LDL < 100
- HDL > 60 (desirable), < 40 (low in males)
- Non-HDL < 130
- TG < 150
CRP
- C-reactive protein
- 0-0.5
- Elevated levels suggests inflammation
FPG
- > 126 consistent with diabetes
- 100-125 is pre-diabetes
- <100 is preferable
- Fasting at least 8 hours
A1C
- <7% per ADA
- Average blood glucose over past 3 months
C-peptide
- Used to distinguish DMI and II
- Decreased or absent in DMI (insulin breakdown product)
TSH
- Increased TSH = hypothyroidism, Decreased TSH = hyperthyroidism
- Levels can be affected by amiodarone and interferons
- Increased (hypothyroidism) due to tyrosine kinase inhibitors, lithium, and carbamazepine
Uric Acid
- Used to diagnose/treat gout
- Increased from diuretics, niacin, low dose aspirin, pyrazinamide, cyclosporine, tacrolimus, select chemotherapy and pancreatic enzyme products
Autoimmune tests
- CRP
- RF (rheumatoid factor)
- ESR (erythrocyte sedimentation rate)
- ANA (antinuclear antibodies)
DILE
- Drug-induced lupus erythematosus
- Drug Causes: anti-TNF agents, hydralazine, isoniazid, methimazole, methyldopa, minocycline, procainamide, propylthiouracil, quinidine, terbinafine
- Discontinue causative agents if DILE suspected
Lactic Acid
-Increased by metformin and NRTIs (HIV drugs)
Prolactin
-Increased with haloperidol, risperidone, and paliperidone
PPD
- Purified Protein Derivative or Mantoux test
- TB skin test
RPR
- Rapid plasma reagin
- Syphilis antibody test
TPMT
- Thiopurine methyltransferase
- Deficiencies place patients at higher risk of myelosuppression if using azathioprine and mercaptopurine
