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Stop the seizures with valproic acid

sodium valproate pills

The bottom line

Valproic acid is used for seizures, mania of bipolar disorder, and migraine prevention. Common side effects include drowsiness, dizziness, headache, tremors, weight gain, nausea, vomiting, diarrhea or constipation, and hair loss. Serious toxicity may affect blood, bone marrow, liver, pancreas, and brain. Allergic reactions and drug interactions are also possible.

Prevention Tips

  • Keep valproic acid up, away and out of reach of children.

  • Take as prescribed.

  • Do not stop valproic acid suddenly since this may lead to seizures.

  • Discuss side effects and interactions with your doctor or pharmacist.

  • Do not take it if pregnant since it can cause birth defects.

  • Do not cut or crush tablets.

  • Be aware of potential for interactions with other drugs, vitamins and dietary supplements.

This Really Happened

A 31-year-old man was started on valproic acid after a generalized tonic-clonic seizure due to a brain tumor. The tumor was then surgically removed. Six days after admission, he became lethargic. Valproic acid level was normal, but plasma ammonia level was elevated. Electroencephalogram (EEG) was abnormal without evidence of seizures. The diagnosis was hyperammonemic encephalopathy due to valproic acid, which was treated with intravenous L-carnitine. Valproic acid was discontinued and he was put on another anticonvulsant.  His mental status improved with complete recovery within 24 hours. EEG became normal and plasma ammonia level decreased.

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What is valproic acid prescribed for?

Valproic acid is an anticonvulsant prescribed for seizures, specifically absence seizures, partial complex seizures, and generalized seizures. It is also used to treat the manic phase of bipolar disorder and to prevent migraine headaches.

Valproic acid works by increasing levels of GABA, which is an inhibitory neurotransmitter. It also prolongs the recovery of inactivated sodium channels in the brain.

 

What are the different oral forms and brands of valproic acid?

The 3 forms are valproic acid (also known as valproate), sodium valproate, and divalproex sodium (also known as valproate semisodium). Divalproex sodium, a mixture of valproic acid and sodium valproate, may have fewer gastrointestinal side effects.

Brand names are Depakene and Stavzor (valproic acid), Depakote (divalproex sodium) and Depacon (sodium valproate). Depakene is available as soft gelatin capsules and as an oral solution. Depakote is available as immediate release tablets, extended release tablets, delayed release tablets, and delayed release sprinkle capsules. Depacon is an intravenous use product. Sodium valproate is available generically as an oral solution. There are also generic formulations of valproic acid and divalproex sodium.

 

What are the side effects of valproic acid?

Common side effects include drowsiness, dizziness, headache, tremors, weight gain, nausea, vomiting, diarrhea or constipation, and hair loss. Valproic acid alters fatty acid metabolism, which can lead to serious toxicity including metabolic acidosis, increased ammonia in the blood, liver damage, pancreatitis, bone marrow depression (low platelets, red cells and/or neutrophils) and cerebral edema (brain swelling). Allergic reactions can also occur with rash, swelling and difficulty breathing. It is also possible for valproic acid to cause agitation, irritability, and depression.

 

Is valproic acid a controlled substance?

No, valproic acid is not a controlled substance. It is available by prescription only.

 

What should I avoid while taking valproic acid?

You should avoid alcohol since there is an increased risk of drowsiness and liver toxicity. Avoid driving until you find out if valproic acid affects your alertness. Potential drug interactions include aspirin, blood thinners, and some dietary supplements that may increase risk of bleeding or liver toxicity. Also avoid carbapenems such as imipenem or meropenem (antibiotics that can lower serum valproic acid levels) and recreational drugs such as cannabis that can increase anxiety or panic.

What should I do if someone accidentally takes valproic acid or takes too much valproic acid?

If someone accidentally takes valproic acid or takes too much valproic acid, serious toxicity is possible. Serum valproic acid levels and other laboratory studies can help determine the severity of the overdose as well as the best treatment for valproic acid toxicity.

If someone takes too much valproic acid, or if you have a question about using valproic acid safely, use the webPOISONCONTROL® online tool to get help, or call your poison center at 1-800-222-1222. Whether online or by phone, expert guidance is always free, confidential, and available 24 hours a day.

References

Alrazooqi MK, Abumuaileq L, Zia S, Kazim S. Massive Valproic Acid Overdose With Confirmed Pharmacobezoar Formation and Neuromuscular Toxicity: A Case Report and Literature Review. Cureus. 2025 Nov 15;17(11):e96884. doi: 10.7759/cureus.96884. 

Ghannoum M, Laliberté M, Nolin TD, MacTier R, Lavergne V, Hoffman RS, Gosselin S; EXTRIP Workgroup. Extracorporeal treatment for valproic acid poisoning: systematic review and recommendations from the EXTRIP workgroup. Clin Toxicol (Phila). 2015 Jun;53(5):454-65. doi: 10.3109/15563650.2015.1035441.

Glatstein M, Bonifacio Rino P, de Pinho S, Scolnik D, Pivko-Levi D, Hoyte C. Levocarnitine for the Treatment of Valproic Acid-Induced Hyperammonemic Encephalopathy in Children: The Experience of a Large, Tertiary Care Pediatric Hospital and a Poison Center. Am J Ther. 2019 May/Jun;26(3):e344-e349. doi: 10.1097/MJT.0000000000000706. 

Juurlink DN. Carbapenems in the management of valproic acid overdose. Br J Clin Pharmacol. 2025 Mar;91(3):648-653. doi: 10.1111/bcp.16376. 

Kadam R, Palkar M, Pingili RB. Mechanisms involved in the valproic acid-induced hepatotoxicity: a comprehensive review. Toxicol Mech Methods. 2025 Jul;35(6):565-580. doi: 10.1080/15376516.2025.2459176. 

Liu R, Xiao L, Hu Y, Yan Q, Liu X. Rescue strategies for valproic acid overdose poisoning: Case series and literature review. Clin Case Rep. 2023 Dec 27;12(1):e8367. doi: 10.1002/ccr3.8367. 

Patel J, Berezowski I, Mazer-Amirshahi M, Frasure SE, Tran QK, Pourmand A. Valproic Acid Overdose: Case Report and Literature Review. J Emerg Med. 2022 Nov;63(5):651-655. doi: 10.1016/j.jemermed.2022.07.009. 

Rigamonti A, Lauria G, Grimod G, Bianchi G, Salmaggi A. Valproate induced hyperammonemic encephalopathy successfully treated with levocarnitine. J Clin Neurosci. 2014 Apr;21(4):690-1. doi: 10.1016/j.jocn.2013.04.033. 

Sztajnkrycer MD. Valproic acid toxicity: overview and management. J Toxicol Clin Toxicol. 2002;40(6):789-801. doi: 10.1081/clt-120014645. Erratum in: J Toxicol Clin Toxicol. 2003;41(4):215. 

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