Routine Medication and Lab Follow-up
Author / Curator: Chris Steele, MD MPH MS
(1) Be concise.
(2) Be evidence-based. (Everything should have a reputable citation and resource)(3) Be clinically relevant. (Avoid unnecessary discussion of pathophysiology and epidemiology if it does not help clinical decision-making).
- 1 Learning Objectives
- 2 Top Teaching Points
- 3 Background
- 4 Management
- 5 Other Teaching Pearls
- 6 Trial Summaries
- 7 Ongoing controversies / New updates
- 8 Teaching Resources
- 9 References
- Know when to schedule a follow-up appointment for a healthy patient.
- Understand which medications should be monitored and what labs to order.
- Learn common labs and screening that should be performed for common primary care diagnoses such as diabetes and HIV.
Top Teaching Points
- Spironolactone should have a potassium monitored every 3 months given the complication of hyperkalemia.
- Beta blockers can be titrated ~2 weeks in the primary care setting. Titrating sooner, especially in heart failure, can lead to bradycardia.
The following section are recommendations for when a provider should schedule routine visits and at what frequency certain labs should be ordered to monitor patients with certain medications or health conditions.
Scheduling an Annual Visit
For healthy individuals, the following can be a baseline to determine when patients should see their primary care provider. This schedule should not be followed for those with illnesses that need more frequent monitoring.
- Age 18-20: Every year.
- Age 21-49: Every 1-3 years.
- Age 50+: Every year.
Scheduling Follow-up for Common Conditions
One of the most challenging aspects of primary care is scheduling an appropriate follow-up appointment for those who need either improved control or frequent monitoring of their diseases. The following table is a list of common conditions and recommendations as to when a PCP should have their patients follow up.
|Disease||What to Monitor||Frequency|
|Diabetes||Please see the Follow-up for Diabetes Section||
|Hypertension||Blood pressure (BP)||
* Labs may need to be ordered before the 3-month visit depending on the hypertensive agent of choice and may need an earlier follow-up appointment.
Medications and Follow-Up Labs
The following is a summary of recommendations for when to order labs for monitoring.
|Medication||Lab(s) or Vitals||Frequency||Complication/Reason to Monitor|
||NB: Do not start or stop the medication if K is >5.5 mEq/L, or GFR is <30 ml/min. For men, this is usually a Cr of 2.5 mg/dL and women a Cr of 2.0 mg/dL.|
|Ace Inhibitors (ACE)
Angiotensin Receptor Blockers (ARB)
|BMP (Cr and K)||
||NB: Discontinue ACE/ARB if potassium .5.5 mEq/L and or serum cr increases 30% within the 1st two months of starting.|
||NB: Titrate beta blockers only every 2 weeks.|
Check 6-8 hrs after dose.
Heart failure- 0.5-1 ng/mL
Atrial fibrillation: 2 ng/mL
Ecreted. through the kidneys
|Diuretics (Both loop and thiazide diuretics)||BMP, Magnesium||
||Patients may need potassium supplementation.|
||NB: Lithium is renally excreted so kidney function should be monitored.
Normal Li trough 0.6-1.2 mEg/L.
Should be a taken 8-12 hrs after dose.
||NB: Metformin can cause megablastic anemia. It is contraindicated in CKD stage 3a or GFR less than 60 ml/min or more simplistically, with women who have serum cr >1.4 mg/dL and men with serum cr >1.5 mg/dl.|
|Niacin||CMP, Uric Acid, Glucose||
||NB: If muscle symptoms, obtain potassium, creatine kinase (CK) and liver function testing (LFTs) to look for myositis.
Niacin can worsen hypophosphatemia, can increase serum uric acid levels and fasting glucose levels.
||NB: Patients with high risk of NSAID induced kidney injury are those over the age of 60, liver failure, heart failure patients, concurrent diuretic or ACE/ARB use, CDK Stage
||NB: Retinoid medications cause worsening diabetes.|
||NB: If muscle symptoms, obtain K, creatinine kinase (CK) and LFTs to look for myositis.
These guidelines are adjusted for patients with heart disease and diabetes who have lower LDL goals.
|Synthroid (Thyroid replacement)||TSH reflux T4/T3||
||NB: Initial dose of Synthroid: 1.6 mcg/kg/day unless patient unless A) Age >50 (should start with 25-50 mcg/kg/day dose) or B) Age >50 with heart disease (should stat with 12.5/25 mcg/kg/day dose)
Subclinical hypothyroidism- 1 mcg/kg/day
||NB: Warfarin is metabolized by the cytochrome (CYP) P450 drug and new medications should be added cautiously.
Patients on warfarin should be part of a Coumadin clinic for adjustment and monitoring.
BMP = Basic Metabolic Panel; CBC=Complete Blood Count; CMP = Complete Metabolic Panel; Cr= Creatinine; INR/PT= International Normalization Ratio and Prothrombin Time; LFTs= Liver Functino Tests; K = Potassium; TSH = Thyroid Stimulating Hormine
Follow-up Labs for Diabetes Patients
|Lab or Exam||Frequency|
|Point of Care Glucose||Every visit or if well controlled, based on the providers opinion.|
|Lipid Panel||Yearly in stable patients and more frequently if not at clinical goal.|
|Kidney Function (GFR)||Yearly creatinine check unless there is underline kidney disease or therapy that shortens the intervals (e.g. ACE inhibitors)|
|Microalbumin or spot protein creatinine ratio||Yearly unless disease present and interval needs to be adjusted.|
|Blood Pressures||Every visit|
|Foot exam||Every 3-6 months|
Follow-up Labs for HIV Patients
The following is an adaptation of the AIDSinfo Guidelines recommended by the Department of Healt and Human Service for monitoring patients with HIV. Please read the HIV page for more information on treating patients with HIV in the primary care setting.
|Lab Test||Start of Care||Start ART Therapy||3 to 6 Months||6 Months||Year||Other|
|CD4 Count||x||Yes, and repeat 2 months after starting therapy||
||After 2 years of therapy with consistently suppressed VL one can adjust to
||Always recheck if ART is switched, there has been non-adherence or clinical assessment suggests failure of treatment.|
|HIV Viral Load||
|CCR5 Antagnoist||Tropism Testing|
|Hepatitis B Screening||Complete if not done on screen||Repeat if received immunity to confirm antibody formation.|
|Hepatitis C Screening||x||Complete if not done on screen|
|Complete Metabolic Panel (Cr, K, Na, Bicarb and Glucose, AST, ALT, Alk Phos)||x||x||x||
|Diabetes Screening (HgA1c and glucose)||x||If patient has diabetes||If patient has pre-diabetes||
|Urinalysis||Check for TAF/TDF regiments (Tenofovir)|
|CBC||x||x||Check for Zidovudine watching for neutropenia and anemia|
x = lab should be obtained.
*Patients at greatest risk for increased cr or K from ace/arbs are those with diabetes, on NSAIDs or immunosuppressive therapies, diuretics, renal artery stenosis or GFR less than 60 mL/min.
Other Teaching Pearls
Ongoing controversies / New updates
What's the latest scuttlebutt? This is a place to include new guidelines, controversies, or other recent updates on the topic.
- Hunt SA, Abraham WT, Chin MH, et al. 2009 focused update incorporated into the ACC/AHA 2005 guidelines for the diagnosis and management of chronic heart failure in adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines developed in collaboration with the International Society for Heart and Lung Transplantation. J Am Coll Cardiol 2009;53:e1-e90.