Basic Lab Measurements in Medication Monitoring

With new regulatory guidelines now in effect, it may be an appropriate time to review common laboratory monitoring with medications commonly used in the elderly. Surveyors will be checking for appropriate labs in assuring therapeutic efficacy and safety in medication management with our residents.

  1. Coumadin- Check PT/INR at least monthly. Monitor more frequently with a change of dose or the addition of certain medications including antibiotics, Dilantin (Phenytoin), some antidepressants and cholesterol medications
  2. Diuretics- (Furosemide, Hydrochlorothiazide) can cause changes in electrolytes. A BMP should be checked 1 week after starting and a BMP, Electrolytes or CMP at regular intervals.
  3. Levothyroxine- A TSH level should be checked 4-6 weeks after start or change of dose and at regular intervals.
  4. Digoxin- Digoxin levels should be at regular intervals and with renal function changes. Also check where drug interactions are suspected. Hypokalemia, hypomagnesaemia & hypocalcaemia can cause digoxin toxicity & arrhythmias. Potassium, magnesium, calcium and renal function should be checked periodically.
  5. HMG-CoA medications- (Zocor, Mevacor, and Crestor)- Check Liver function 6-12 weeks after starting and every 6 months. Lipid Profile should be checked periodically.
  6. Phenytoin (Dilantin)-Phenytoin levels should be checked at regular intervals along with CBC, albumin & liver function tests periodically.
  7. Amiodarone (Cordarone)-Periodic checking of Liver function, Thyroid function tests should be checked due to possible hypo or hyperthyroidism. CBC should be checked periodically.
    Blood sugar should be checked often with those taking antidiabetic or hypoglycemic medications. Common tests include fingerstick blood sugar, monthly FBS or HgbA1C q 3 months. Metformin should include serum creatinine/BUN levels with a CBC. Actos & Avandia should also have liver function tested frequently during the first year then periodically.
  8. Iron, B-12 or Folate-should have a CBC checked within the frst 30 days, then every 6 months.
  9. Residents taking NSAIDs- should also have a CBC checked regularly to monitor for possible bleeding. Serum levels for those taking Phenobarbital, Valproic Acid, Tegretol, and Theophylline should be checked regularly.
  10. Your consultant pharmacist strives to make proper lab monitoring a priority during the medication regimen review. A list of suggested labs is posted in the Gayco policy & procedure book. As always, do not hesitate to call your Gayco or consultant pharmacist for any questions .