Special Test Information

This section provides information for tests with special considerations. 


Meadville Medical Center Liberty Street Facility 751 Liberty Street
Liberty Street Facility
751 Liberty Street, Meadville, PA, 16335
View Location Details
Meadville Medical Center, One Vernon Place, 11277 Vernon Place Rd. Meadville, PA
One Vernon Place
11277 Vernon Place, Meadville, PA, 16335
View Location Details

Tests Requiring Scheduled Collection

TestRequired Scheduled Collection
2 and 3 hour Glucose ToleranceMonday-Friday, scheduled at Liberty Street Outpatient site only
Platelet Aggregation Study

Vitalant Von Willebrand Profile
These specimens MUST be scheduled at Meadville Medical Center Laboratory, Liberty Street. Specimens for coagulation studies must arrive within 4 hours at the Vitalant Specialty lab in Pittsburgh.

Therapeutic Drug Monitoring

Monitoring of Anticoagulation Therapies

  • Warfarin: Monitoring of this anticoagulant therapy is best achieved by Protime (PT) testing and the subsequent calculation of the INR.
  • Unfractionated Heparin: This anticoagulant is monitored by Anti-Xa and only while admitted in the hospital.
  • Low Molecular Weight Heparin: This anticoagulant is monitored by Anti-Xa.

***Disclaimer: Currently there are no available techniques to monitor the “New” Oral Anticoagulants (NOAs) on the market i.e. Pradaxa (dabigatran), Xarelto (rivaroxaban), or Eliquis (apixaban). Based upon literature, it is suggested that patients wait 24 hours before beginning coagulation testing. Of note: The dose of these NOAs does not correlate well with the measured PT/INR and hence, anticoagulant testing when using these NOAs may be an unreliable guide to antithrombotic efficacy. ***

Make sure the drug is not hanging or infusing as you are drawing the level. If drawing through an existing catheter, make sure the line has been flushed appropriately.

Monitoring of Drugs at MMC

The following information has been reviewed and updated by MMC pharmacy:

DrugTherapeutic RangeSampling Times
(APTT) Activated Partial Thromboplastin Time (Heparin®)Normal 24-35 seconds
Therapeutic range- 60.2-103 seconds
Per Heparin Protocol IV: 6 hours after initiation or changes in dose
Aminoglycosides Including:
– levels are sendouts and desired levels are different than gent & tobra trough/peak levels, but timing of the sample is the same.
Trough: Less than 2 mcg/mL
Peak: 5-10 mcg/mL(depending on indication)
Random: See Nomogram if EID
Trough: IV or IM therapy: within 30 minutes prior to dose
Peak: IV: 30 minutes after 30 minute infusion
IM: 1 hr after injection
Random: 8-12 hours after 60 minute infusion for extended interval dosing (EID)
4-12 µg/mLTrough: 15 minutes prior to dose
Peak: 6-8 hours post dose
Digoxin0.8-2.0 ng/mLTrough:
(Oral) 15 minutes prior or 12 hours post dose
(IV) 15 minutes prior or 6-12 hours post dose

Phenytoin – Total (Dilantin)* Fosphenytoin (Cerebyx) Free Phenytoin (only in pts with altered protein binding-ex .uremia, hepatic disease, late pregnancy, postpartum or head injury)10-20 mcg/mL
10-20 mcg/mL
1-2.5 mcg/mL
15 min prior to dose
Peak: 6-8 hours post dose
Trough:15 min prior to dose
Peak: 2 hours after IV dose; 4 hours after IM dose.
Lithium *0.5-1.5 mEq/LTrough: 15 minutes prior to dose
Lovenox (enoxaparin)
One (Dose?) Daily
Two (Doses?) Daily
1-2 IU/mL
0.6-1 IU/mL
0.2-0.5 IU/mL
Peak (Factor Xa level):Four hours after dose is administered
Phenobarbital *10-30 mg/mL
>40 Critical
Trough: 15 minutes prior to dose
Prothrombin Time (INR) (Coumadin Therapy)INR: Therapeutic 2-3 or 2.5-3.5, depending on indicationPreferable to keep the time of draws consistent
16-18 hours after dose.
Liquid or fast release tab
Slow-release product
10-20 µg/mLORAL:
just before dose
Peak: 1 hour after dose
IV: 30 minutes post loading dose, then 18-24 hours after initiation
Valproic Acid (Depakene®/ Depakote®) *50-100 µg/mLTrough: 15 minutes prior to dose
Peak levels are only indicated in certain situations –contact pharmacy for more info
Trough: 10-15 mcg/mL

For pneumonia, osteomyelitis, etc. 15-20 mcg/mL

Peak: 30 - 40 mcg/mL
Trough: within 30 minutes prior to dose
Peak: 1 hour after completion of 1 hour infusion

*A trough level is appropriate for routine evaluation. For evaluation of toxicity, a peak sample is recommended. (REVISED by MMC Pharmacy 5/2005,11/2006, 1/2009, 3/2013)


  1. Young L, Koda-Kimble M, eds Applied Therapeutics: The Clinical Use of Drugs Eighth Edition. Vancouver: Applied Therapeutics, 2005.
  2. Interpretation of Diagnostic Tests. Jacques Wallach, M.D. Lippencott Williams & Wilkins 2000
  3. Lexi-Comp Online, accessed January 2009
  4. Micromedex ® Drug Information, accessed January 2009
  5. Basic Clinical Pharmacokinetics 3rd edition. Winters ME. Applied Therapeutics, Inc Vancouver, WA.1994.
Click to access the login or register cheese