Valproic acid (VPA), is a histone deacetylase (HDAC) inhibitor.
It has found clinical use as an anticonvulsant and mood-stabilizing drug, primarily in the treatment of epilepsy, bipolar disorder and prevention of migraine headaches. VPA is a liquid at room temperature, but it can be reacted with a base such as sodium hydroxide to form the salt sodium valproate, which is a solid.
The acid, salt, or a mixture of the two (valproate semisodium) are marketed under a number of different brand names, including: Depakote, Epilim, Valparin, Valpro, Vilapro and Stavzor. It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.
Both valproic acid and levetiracetam are antiepileptic drugs, often used either alone or in combination.
A study compares valproate (VPA) with levetiracetam (LEV) as an intravenous (i.v.) anticonvulsant treatment in intensive care patients suffering from aneurysmal subarachnoid hemorrhage (aSAH) with a high risk of seizures.
A prospective, single-center patient registry of 35 intensive care unit (ICU) patients with onset seizure and/or high risk of seizures underwent an anticonvulsive, first-line single treatment regimen either with VPA or LEV. Plasma concentrations (pc), interactions between drugs in the ICU context, adverse effects and seizure occurrences were observed and recorded.
A significant decrease in the pc in patients treated with LEV was observed after changing from intravenous (160±51μmol/l) to enteral liquid application (113±58μmol/l), corresponding to a 70.3% bioavailability for enteral liquid applications. The pc in VPA patients decreased significantly, from (491±138μmol/l) to (141±50μmol/l), after adding meropenem to the therapy (p<0.05). Three epileptic seizures occurred during anticonvulsive therapy in the LEV group, and two in the VPA group, including one non-convulsive status epilepticus (NCSE).
Though this finding needs further verification, the enteral liquid application of levetiracetam seems to be associated with lower bioavailability than the common oral application of levetiracetam. The use of the antibiotic drug meropenem together with valproic acid leads to lower pc levels in patients treated with of valproic acid. For clinical practice, this indicates the need to monitor the levels of valproic acid in combination with meropenem 1).
The neuroprotective effects of VPA have been demonstrated in several models of acute CNS injuries, such as stroke, TBI, and SCI. VPA protects the brain from injury progression via anti-inflammatory, anti-apoptotic, and neurotrophic effects 2).
Valproic acid (VPA) is a commonly used drug for epilepsy, psychiatric disorders and migraine and is frequently used in neurosurgical intensive care units. Though most of its side-effects are mild and transient, certain idiosyncratic side-effects have been attributed to VPA. Valproate induced hyperammonemia (VIH) is one such side-effect 3)
Valproate encephalopathy 4).
Interstitial pneumonitis 5).