Why measure drug levels?
Valproic acid is used for epilepsy and bipolar disorder. Its effectiveness and toxicity depend on the concentration in the blood, which at the same dose varies several times in different people due to the characteristics of metabolism, interactions with other drugs and liver function. Concentration monitoring answers specific questions: the attacks continue due to an insufficient dose or the drug is simply not suitable; whether drowsiness, tremor and nausea are associated with overdose; whether the patient takes the drug regularly. Blood is donated before taking the next dose, when the concentration is minimal. Monitoring is especially important during pregnancy, in children, when combined with other antiepileptic drugs and in liver diseases.
How to prepare to donate blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important.
The analysis must be interpreted by a doctor: an isolated indicator without a clinical context is often misleading and leads to unnecessary examinations.