From the Guidelines
The most appropriate response by the nurse practitioner is to continue the current valproate dosage as the serum level of 140 μg/mL falls within the therapeutic range for bipolar disorder. The therapeutic range for valproate in treating bipolar disorder is typically 50-125 μg/mL, though some sources extend this range to 50-150 μg/mL 1. While the patient's level is on the higher end of this range, it is not in the toxic range (generally considered above 150 μg/mL). The nurse practitioner should monitor the patient for any side effects such as sedation, tremor, gastrointestinal disturbances, or liver function abnormalities. Regular follow-up appointments should be scheduled to continue monitoring serum levels and assess treatment efficacy.
Key Considerations
- If the patient is stable and showing good response to treatment without significant side effects, maintaining the current dose is appropriate.
- However, if the patient is experiencing troublesome side effects, a slight dose reduction might be considered while still maintaining therapeutic levels.
- It is essential to advise patients and families about presenting symptoms of potential adverse effects because periodic monitoring does not ensure that abnormalities will be readily identified 1.
Monitoring Requirements
- Serum drug levels, plus hepatic and hematological indices, should be monitored periodically (every 3-6 months) 1.
- The nurse practitioner should also be aware of the concerns raised regarding valproate and the development of polycystic ovary disease in females 1.
From the Research
Therapeutic Serum Valproate Level
The patient's serum valproate level is 140 µg/mL. According to the study 2, higher serum levels, particularly above 110 microg/ml, are associated with more reports of weight gain, sedation, and reductions in platelet count.
Appropriate Response by the Nurse Practitioner
The nurse practitioner should:
- Monitor the patient's condition and adjust the valproate dose as needed to minimize side effects
- Consider the patient's overall health and medical history when making decisions about valproate treatment
- Be aware of the potential for valproate to be associated with an increased rate of polycystic ovarian syndrome, with increased weight contributing to the risk 2
- Note that the therapeutic serum valproate level for maintenance therapy in bipolar disorder is not well established, but a study 3 found that trough serum valproate levels were 52.2 +/- 20.4 microg/ml in bipolar I disorder patients and 41.0 +/- 18.3 microg/ml in bipolar II disorder patients
Key Considerations
- The patient's serum valproate level is above the level associated with increased side effects
- The nurse practitioner should carefully monitor the patient's condition and adjust treatment as needed
- Valproate is effective in treating mania and preventing episodes of bipolar disorder, but its use requires careful consideration of potential side effects and interactions with other medications 4, 2, 5