Lab Values and Drug Monitoring Flashcards
Describe a CBC
- Complete blood count
- Analyzes WBCs, neutrophils, RBCs, and platelets
- Includes hemoglobin and hematocrit
Average RBC and platelet lifespan
RBC (120 days)
Platelet (7-10 days)
Describe a BMP
- Basic metabolic panel
- Includes electrolytes and glucose, acid/base, and renal function
Draw and label the fishbone for BMP and CBC
[see NAPLEX guide for picture]
Calcium and ionized calcium normal range
Calcium: 8.5-10.5 mg/dL
Ionized: 4.5-5.1 mg/dL
Common causes for calcium increases or decreases
Hyper: supplementation, Vitamin D, thiazide diuretics
Hypo: steroids, long-term heparin, loop diuretics, bisphosphonates, cinacalcet, calcitonin, foscarnet, topiramate
Chloride normal range
95-106 mEq/L
Magnesium normal range
1.3-2.1 mEq/L
Common causes for Mg decreases
PPI and diuretic use, amphotericin, foscarnet, echinocandins, diarrhea, chronic alcohol intake
Phosphate normal range
2.3-4.7 mg/dL
Common causes for phosphate increases or decreases
Increased in renal failure
Decreased d/t phosphate binders, foscarnet, oral calcium intake
Potassium normal range
3.5-5 mEq/L
Common causes for potassium increases or decreases
Increased due to ACEIs/ARBs, aldosterone receptor antagonists, aliskiren, NSAIDs, cyclosporine, tacarolimus, mycophenolate, drospirenone-containing oral contraceptives, bactrim, chronic heparin use, canagliflozin, pentamidine
Decreased due to steroids, beta-2 agonists, conivaptan, diuretics, insulin, mycophenolate
Sodium normal range
135-145 mEq/L
Common causes for sodium increases or decreases
Increased due to hypertonic saline
Decreased due to carbamazepine, oxcarbazepine, SSRIs, diuretics, desmopressin
Bicarbonate normal range
Venous: 24-30 mEq/L
Arterial: 22-26 mEq/L
Common causes for bicarbonate increases or decreases
Increased due to loop diuretics, systemic steroids
Decreased due to topiramate, zonisamide, salicylate overdose
BUN normal range
7-20 mg/dL
Common causes for BUN increases
Renal impairment and dehydration (used with SCr to determine fluid status and renal function)
Serum creatinine normal range
0.6-1.3 mg/dL
Common causes for SCr increases or decreases
Increased due to drugs that impair renal function, false increase due to Bactrim and H2RAs
Decreased due to low muscle mass, amputation, hemodilution
Anion gap normal range
5-12 mEq/L
WBC normal range
4,000-11,000 cells/mm^3
Common causes for WBC increases or decreases
Increased due to systemic steroids, colony stimulating factors, epinephrine, infection or inflammation
Decreased due to clozapine, chemotherapy targeting the bone marrow. carbamazepine, cephalosporins, immunosuppressants, procainamide, vancomycin
Neutrophils normal range
45-73%
Bands normal range
3-5%
These are immature neutrophils, releases from marrow to fight infection (left shift)
Hemoglobin and hematocrit normal ranges
Hemoglobin:
Men: 13.5-18 g/dL
Women: 12-16 g/dL
Hematocrit:
Men: 38-50%
Women: 36-46%
Mean corpuscular volume (MCV) normal range
80-100 fL
Common causes for MCV increases or decreases
Increased due to B12 or folate deficiency, alcoholism, chronic liver disease, hypothyroidism
Decreased due to iron deficiency anemia, hemolytic anemia, lead poisoning, thalassemia
Common causes for folate decreases
Phenytoin/fosphenytoin, phenobarbital, primidone, methotrexate, sulfasalazine, bactrim
Common causes for B12 deficiency
PPIs, metformin, colchicine, chloramphenicol
Describe Antifactor Xa Activity
- Used to monitor LMWHs by obtaining peak anti-Xa 4 hours after dose
- Monitoring recommended in pregnancy
- Monitoring may be recommended in obesity, low body weight, pediatrics, elderly, or renal insufficiency
Prothrombin time/INR normal range
Prothrombin time: 10-13 seconds
INR: <1.2 (for those not on warfarin)
Drugs that may falsely elevate prothrombin time/INR
Daptomycin, oritavancin, telavancin
Describe Activated Partial Thromboplastin Time (aPTT/PTT)
Used to monitor unfractionated heparin and direct thrombin inhibitors (e.g. argatroban)
aPTT/PTT normal range
22-38 seconds
Treatment goal on heparin is 1.5-2.5x normal range
Platelets normal range
150,000-400,000/mm^3
Common causes for platelet deficiencies
Heparin, LMWHs, fondaparinux, glycoprotein IIb/IIIa receptor antagonists, linezolid, valproic acid, chemotherapy targeting the bone marrow
Albumin normal range
3.5-5 g/dL
Aspartate aminotransferase and alanine aminotransferase normal ranges
AST: 10-40 units/L
ALT: 10-40 units/L
Bilirubin normal range
0.1-1.2 mg/dL
Amylase normal range
60-80 units/L
Lipase normal range
5-160 units/L
Creatinine kinase/creatinine phosphokinase normal range
Males: 55-170 IU/L
Females: 30-135 IU/L
Common causes for CK increases
Daptomycin, quinupristin/dalfopristin, statins, fibrates, emtricitabine, tenofovir, tipranavir, raltegravir, dolutegravir, telbivudine
Muscle damage, cardiac conditions
B-Type Natriuretic Peptide Normal Range
<100 pg/mL or ng/L
N-Terminal-ProBNP (NT-proBNP) Normal Range
Males: <61 pg/mL
Females: 12-151 pg/mL
Total cholesterol normal range
<200 mg/dL
HDL normal range
<40 mg/dL = low
60+ mg/dL = desirable
LDL normal range
70-189
TG normal range
<150 mg/dL
C-reactive protein (CRP) normal range
0-0.5 mg/dL
TSH and T4 normal ranges
TSH: 0.3-3 mIU/L
T4 (total thyroxine): 4.5-100.9 mcg/dL
Common causes for TSH increases or decreases
Increased or decreased due to amiodarone, interferons
Increased (hypothyroidism) due to lithium, carbamazepine, oxcarbazepine
Common causes for uric acid increases
Diuretics, niacin, high doses of aspirin, pyrazinamide, cyclosporine, tacrolimus, ribacirin, some pancreatic enzyme products
Rheumatoid factor (RF) normal range
<40 IU/mL
Erythrocyte sedimentation rate (ESR) normal range
Males: = 20 mm/hr Females: = 30 mm/hr
Common drug-induced lupus erythematosus (DILE) offending agents
Anti-TNF agents, hydralazine, isoniazid, methimazole, methyldopa, minocycline, procainamide, propylthiouracil, quinidine, terbinafine
CD4+ T Lymphocyte Count Normal Range
800-1100 cells/mm^3
Arterial blood gas normal ranges
pH: 7.35-7.45 pCO2: 35-45 mmHg pO2: 80-100 mmHg HCO3: 22-26 mEq/L O2 Sat: >95%
Amikacin (traditional dosing) usual therapeutic range
Peak: 20-30 mcg/mL
Trough: <5 mcg/mL
Carbamazepine usual therapeutic range
4-12 mcg/mL
Digoxin usual therapeutic range
- 8-2 ng/mL (AFib)
0. 5-0.9 ng/mL (HF)
Gentamicin (traditional dosing) usual therapeutic range
Peak: 5-12 mcg/mL
Trough: <2 mcg/mL
Lithium usual therapeutic range
0.6-1.2 mEq/L (up to 1.5 for acute symptoms)
Enoxaparin usual therapeutic range
VTE treatment (daily): 1-2 anti-Xa units/mL VTE treatment (q12h): 0.6-1.2 anti-Xa units/mL Recurrent VTE prophylaxis in pregnancy: 0.2-0.6 anti-Xa units/mL
Phenobarbital/Primidone usual therapeutic range
20-40 mcg/mL
Phenytoin/fosphenytoin usual therapeutic range
10-20 mcg/mL
Free phenytoin usual therapeutic range
1-2.5 mcg/mL
Procainamide, NAPA, and combined usual therapeutic range
4-10 mcg/ml
15-25 mcg/mL
10-30 mcg/mL
Theophylline usual therapeutic range
5-15 mcg/mL
5-10 mcg/mL (neonates)
Tobramycin (traditional dosing) usual therapeutic range
Peak: 5-10 mcg/mL
Trough: <2 mcg/mL
Valproic acid usual therapeutic range
50-100 mcg/mL (up to 150 in some)
Vancomycin usual therapeutic range
Trough: 15-20 mcg/mL for most serious infections, 10-15 mcg/mL for other infections
Warfarin usual therapeutic range
2-3 or 2.5-3.5 in patients with mechanical mitral valves