Check Lithium Related Side Effects Without Blood Test

Question

Situation:

• A middle aged patient with no health insurance and a well documented history of moderate to severe bipolar disorder visits a low cost clinic.

• The patient has a just lapsed lithium prescription and cannot get a refill directly at a pharmacy. The patient needs a new prescription for lithium, and this is the reason for the visit.

• The health care provider would like to draw blood to test renal function.

• Unfortunately, lab tests are not provided free, and the cost of the blood test is outside of the reach of the patient. A urine test is also too expensive.

• There is more than one patient with this situation.

Question:

Is there an alternative method(without lab tests) that can assess whether the prescription can be safely filled?

Assume there is one doctor/physician assistant/nurse practitioner donating time.

Answer 1

Blood tests to determine lithium levels are the gold standard for assessing the efficacy of lithium therapy. That said, a patient on a stable dose with no major adverse reactions is presumably within their body's therapeutic range. If there is preexisting renal dysfunction, that brings in a whole new can of worms. The signs and symptoms of lithium overdose are well documented and easily researched. I see many similar scenarios with metformin. Renal function should always to tested periodically throughout treatment but is rarely performed. I say that to say this, if the patient is tolerating the medication, isn't showing signs of renal dysfunction, and has no major reactions, I think it should be OK to prescribe/dispense the medication while diligently monitoring the patient for and changes.