Sodium valproate - good tools also need good methods

Sodium valproate is a broad-spectrum anti-epileptic drug, suitable for generalized, partial or other types of epilepsy, and has varying degrees of antagonism against convulsions caused by various reasons. It is an ideal anti-epileptic drug because of its broad anti-epileptic spectrum, good clinical effect, rapid onset, low recurrence rate, and good control of the disease with single-drug treatment.

However, no matter how good the medicine is, it must be used in the most appropriate way to achieve the best therapeutic effect. So what should we pay attention to when using sodium valproate?

1. What do you need to know before taking the medicine?

1. If you have the following conditions, you cannot use sodium valproate. Please tell your doctor all the diseases you have been diagnosed with and the treatment you are receiving:

Liver disease or significant liver damage (such as hepatitis, hepatic porphyria).

The individual or a family member has suffered from drug-induced jaundice or severe hepatitis (especially drug-induced).

Urea cycle disorders.

Mitochondrial diseases, such as Alpers-Huttenlocher syndrome.

2. If you have renal insufficiency, please inform your doctor in advance. Your dose may need to be adjusted.

3. Sodium valproate is contraindicated in children under 2 years of age who are suspected of having mitochondrial disease.

2. Do not stop taking sodium valproate arbitrarily after use

In general, sodium valproate can only be gradually reduced and discontinued unless serious adverse reactions occur. Because if the drug is discontinued suddenly, there is a high possibility of status epilepticus accompanied by hypoxia and life-threatening. For patients who have previously received other anti-epileptic drugs, the use of sodium valproate sustained-release tablets should be gradual, reaching the optimal dose within 2 weeks, and other treatments should be gradually reduced to discontinuation. If other anti-epileptic drugs are needed, they should be added gradually.

3. Side effects of sodium valproate

1. Digestive system: Common symptoms include nausea, vomiting, anorexia, diarrhea, etc., which generally do not lead to drug discontinuation. It should be noted that sodium valproate can cause liver damage (pay attention to monitor liver function) and pancreatitis, which can be very serious in rare cases.

2. Nervous system: tremor, encephalopathy (may not be related to blood ammonia, but there is also hyperammonemic encephalopathy). When encephalopathy occurs, it must be identified in time, and it will generally improve after stopping the drug.

3. Reproductive system: It can cause menstrual disorders or amenorrhea, polycystic ovary syndrome, and strong teratogenicity. Therefore, young women should only consider using it when the benefits of treatment outweigh the risks, and folic acid and vitamin K should be supplemented when using it.

4. Metabolic and nutritional abnormalities: Common: hyponatremia, weight gain. Since weight gain is a factor in PCOS, it should be carefully monitored. Overweight or obese patients should pay attention to weight control.

IV. Common drug/food interactions of sodium valproate

1. Sodium valproate is a liver enzyme inhibitor, and its effects are most obvious when used in combination with lamotrigine. The dose of lamotrigine should be appropriately reduced, otherwise the chance of adverse reactions such as rash will increase. These two drugs are often used in combination in clinical practice, so special attention should be paid.

2. Carbapenem antibiotics (imipenem, meropenem, etc.) can significantly reduce the concentration of valproate. Imipenem and meropenem are special-grade antibacterial drugs for refractory infections, but when the two are used together, the blood concentration of valproate sodium drops significantly, which is worth noting!

3. Avoid drinking alcohol during medication, as combined use may enhance the sedative effect.

5. Precautions for taking at home

1. Sodium valproate sustained-release tablets should be swallowed whole. They can be broken along the score line for oral administration, but should not be crushed or chewed.

2. Sodium valproate sustained-release tablets may cause drowsiness and may affect driving and mechanical operation.

3. Sodium valproate sustained-release tablets are very easy to absorb moisture. There is a granular desiccant in the bottle cap, which should be sealed and stored in a dry place below 25°C. Do not store in the bathroom or kitchen.

4. If you miss a dose, take it as soon as you remember. However, if it is close to the next dose, you do not need to take it and take it as usual. Do not use a double dose at one time.

5. Suicidal thoughts and behaviors may occur after taking the drug. Family members are requested to closely monitor the patient during medication. If the patient becomes depressed, nervous, restless, complaining, has a panic attack, or has mood or behavior changes, please seek medical attention immediately.

6. If the frequency and severity of epileptic seizures increase or even new symptoms occur after taking the medicine, please see a doctor immediately.

7. During medication, please avoid taking medicines that can be converted into valproic acid in the body, such as divalproex, valproamide, etc., to prevent excessive valproic acid in the body.

1. Other matters needing attention:

1. It is recommended that you check your complete blood count, liver and kidney function regularly during medication. It is best to check liver function every 1-2 months during the first six months of medication, and then extend the interval.

2. Interference with diagnosis: urine ketone test may show false positive and thyroid function test may be affected.

3. Slight increase in lactate dehydrogenase, alanine aminotransferase, and aspartate aminotransferase, indicating asymptomatic liver poisoning. Serum bilirubin may increase, indicating potential severe liver poisoning.

4. You need to go to the hospital regularly to monitor the blood concentration of sodium valproate.

Because the pharmacokinetic parameters of sodium valproate vary greatly from person to person and may be affected by combined medication, as well as the patient's age, weight and other physiological factors, pathological factors such as primary diseases and the influence of combined medication, timely monitoring of blood drug concentrations should be performed, and based on the results of blood drug concentration monitoring, the dosage should be adjusted in a timely manner, an individualized dosing plan should be formulated, and corresponding pharmaceutical monitoring measures should be taken to make the use of valproate safer, more reasonable and effective.

【References】

[1] Zhou Xun, Chen Shun, Zong Chuanfeng, et al. Correlation analysis between sodium valproate and its metabolites and liver injury[J]. Journal of Pharmaceutical Practice, 2020, 038(003):273-276.

[2] Shi Lei, Qian Jun, Tang Jingbo, et al. Monitoring of blood concentration of sodium valproate in the treatment of epilepsy[J]. Chinese Journal of Hospital Pharmacy, 2001, 21(006):346-347.

[3] Drug instructions.