Valproic acid is an anticonvulsant medication that is used to prevent seizures in adults and children and help even out the moods in the manic phase of bipolar disorder.
It is also sometimes given to help with recurrent migraines to help stop them from happening.
Valproic acid is the generic name of a widely used type of anti-seizure medicine. Valproic acid is processed in the liver into valproate, a form that works in the body.
Other seizure medications (valproic acid, sodium valproate, and divalproex sodium) are changed into valproate by the intestine, so they work in the same way as valproic acid.
Valproate calms overactivity in the brain. It does this by stopping the breakdown of the chemical, gamma-aminobutyric acid (GABA). GABA calms the brain by blocking certain brain signals, leading to a calming effect. When valproate stops its breakdown, there is more GABA.
If you are taking one of these seizure medications, it is important that you are having the correct level of the drug – enough to prevent symptoms without causing side effects.
To make sure your dosage is correct, you will be tested before starting on the medication and then regularly to make sure that the amount of valproate in your blood is at the right level and is stable. If your dose seems to be working, regular blood tests can help ensure that valproate levels remain steady. The test will also be used if you need to have your dose adjusted.
Valproate blood levels must stay within a narrow range for the drug to work properly. Too little and there may be a recurrence of your symptoms – seizures, mania or migraines – too much and you may experience side effects. Your doctor will be particularly concerned about preventing any damage to your liver.
This balance is not always easily achieved. Valproate is processed by the liver and people differ in how quickly their liver breaks it down. Your age and the health of your liver will make a difference. Very young and elderly people are more likely to experience increased side effects. Valproate levels are also affected by other drugs such as carbamazepine, phenytoin, lamotrigine and phenobarbital. These drugs increase the rate that valproic acid is processed in the liver, and in doing so, decrease the amount of it in the blood.
Valproate and pregnancy
Valproate should not be used if you are of childbearing age, and it is possible that you could become pregnant, even if you are not currently planning to have children. Valproate can seriously harm an unborn baby by causing a condition called Fetal Valproate Syndrome (FVS). Babies with FVS are at risk of birth defects and lifelong growth and learning problems. Some babies are only mildly affected, some may appear to be unaffected, but others may have more serious difficulties. If there is a possibility you could become pregnant and are taking valproate, it is important that you do not stop taking your medication but seek urgent advice from your doctor so they can give you the help and advice you need.
Sample
Blood.
Any preparation?
You should talk to your doctor about the timing of sample collection. Since dosage timing varies, and some types of valproate are time-released, collection specifics may vary. Often, the recommended time for sample collection is just before the next dose is taken. This ensures that the minimum amount of drug to be effective is maintained in the blood.
Reading your test report
The amount of valproate needed in your body to be effective, called the therapeutic range, is 50 - 120 µg/mL. Within this range, most people will respond without too many side effects. However, response varies with each person. Some people will experience seizures, mood swings or migraines at the low end of the therapeutic range while others will experience unpleasant side effects at the upper end. For the best outcomes you will need to work closely with your doctors to find the dosage and amount that works the best for you.
In general, if valproate results are within the therapeutic range, you are not having recurrent seizures, mood swings or migraines, and you are not experiencing significant side effects, then the dosage of valproate you are taking is correct. You should not increase, decrease or stop taking your medication without consulting your doctors.
A variety of prescribed drugs, over-the-counter medications and supplements can increase, decrease or interfere with the amount of valproate in the blood. You should talk to your doctor about all the drugs and supplements you are taking.
While severe liver injury is rare, mild increases in liver function tests such as AST and ALT occur in up to 20 per cent of people taking valproic acid. This may occur within the first few months of therapy and then usually return to normal.
The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell themeverything you think might help.
You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.
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