From the Guidelines
Regular monitoring of valproate levels, liver function tests, complete blood counts, and pregnancy tests is crucial for patients on this medication, with assessments performed every 3-6 months. Ongoing labs assessment for valproate should include serum valproate levels, which should be checked every 3-6 months once stable dosing is achieved, as recommended by Kowatch and DelBello 1. The target therapeutic range for valproate levels is typically between 50-100 μg/mL.
Key Monitoring Parameters
- Complete blood count (CBC) should be checked before starting treatment and periodically thereafter to monitor for thrombocytopenia and leukopenia, as valproate can cause hematological abnormalities 1.
- Liver function tests (LFTs) should be performed at baseline, frequently during the first six months, then periodically, as valproate can cause hepatotoxicity 1.
- Serum ammonia levels should be checked if encephalopathy is suspected.
- Kidney function tests are recommended at baseline and periodically.
- Additionally, monitor electrolytes, particularly sodium, and consider checking vitamin D, folate, and calcium levels annually as valproate may affect bone health.
- Pregnancy tests are important for women of childbearing age due to valproate's teratogenic effects 1. These monitoring parameters help ensure safe and effective treatment while minimizing adverse effects from this anticonvulsant medication. It is also essential to advise patients and families about presenting symptoms of potential adverse effects, as periodic monitoring does not ensure that abnormalities will be readily identified 1.
From the FDA Drug Label
Because of reports of thrombocytopenia, inhibition of the secondary phase of platelet aggregation, and abnormal coagulation parameters, (e.g., low fibrinogen), platelet counts and coagulation tests are recommended before initiating therapy and at periodic intervals. Clinical management and assessment should include examination of blood ammonia levels Liver function tests should be performed prior to therapy and at frequent intervals thereafter, especially during the first six months.
Ongoing labs assessment for valproate includes:
- Platelet counts
- Coagulation tests
- Blood ammonia levels
- Liver function tests
From the Research
Ongoing Labs Assessment for Valproate
The following labs assessment is needed for valproate:
- Blood studies to monitor for liver failure, as valproate is associated with rare but serious adverse effects like liver failure 3
- Platelet count to monitor for thrombocytopenia, as valproate can cause a decrease in platelet count 4, 5, 6
- Complete blood count to monitor for changes in red blood cell count, as valproate can cause a reduction in red blood cell count 5
- Liver function tests, such as serum protein, albumin, gamma-glutamyltransferase (gamma-GT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase, to monitor for impaired liver synthetic function 5
- Coagulation studies to monitor for changes in serum fibrinogen and thrombin time 5
- Vitamin B12 and folate levels to monitor for changes in these parameters 5
Frequency of Labs Assessment
The frequency of labs assessment may vary depending on the individual patient and the specific concerns of the healthcare provider. However, based on the available evidence, it is recommended to:
- Monitor platelet count and liver function tests regularly, especially in the first few months of valproate therapy 4, 6
- Monitor complete blood count and coagulation studies periodically, especially in patients with a history of bleeding disorders or liver disease 5
Clinical Monitoring
In addition to labs assessment, clinical monitoring is also important to detect early signs of valproate-associated liver failure or other adverse effects. This includes: