Is there a liquid formulation of divalproex (valproate) sodium available?

Liquid Formulations of Divalproex Sodium

No liquid formulation of divalproex sodium is commercially available; however, valproic acid (the active component) is available as an oral solution at 250 mg/5 mL concentration. 1

Understanding the Formulation Difference

• Divalproex sodium is a stable coordination compound of sodium valproate and valproic acid that dissociates to the valproate ion in the gastrointestinal tract 1
• Valproic acid oral solution delivers the same active valproate ion systemically as divalproex sodium products, making them therapeutically equivalent 1
• All oral valproate formulations (liquid, solid, or sprinkle) deliver equivalent quantities of valproate ion systemically, though absorption rates may vary 1

Available Oral Formulations

Liquid Option

• Valproic acid oral solution is the only liquid formulation available, providing 250 mg per 5 mL 1
• This solution is completely bioavailable and therapeutically equivalent to divalproex sodium tablets 1, 2

Solid Alternatives for Patients with Swallowing Difficulties

• Divalproex sodium sprinkle capsules can be opened and contents sprinkled on food, providing an alternative to liquid for patients who cannot swallow tablets 1
• The sprinkle formulation shows minimal change in absorption rate when administered with food (Tmax increases from 3.3 to 4.8 hours) 1

Clinical Equivalence Considerations

• Bioavailability is equivalent across all oral valproate formulations—differences in Tmax and Cmax are of minor clinical importance under steady-state conditions achieved in chronic epilepsy treatment 1
• The primary determinant of seizure control is total daily systemic bioavailability (extent of absorption), not peak-to-trough concentration ratios 1
• Substitution between valproic acid solution and divalproex sodium formulations should cause no clinical problems in epilepsy management 1

Important Monitoring Caveat

• Close monitoring is warranted when switching formulations: any changes in dosage administration or formulation should be accompanied by close monitoring of clinical status and valproate plasma concentrations 1
• The therapeutic range for epilepsy is commonly 50-100 mcg/mL of total valproate, though some patients may be controlled with different concentrations 1

Practical Prescribing Guidance

• When prescribing for a patient requiring liquid medication, write for "valproic acid oral solution" rather than "divalproex sodium liquid" 1
• The typical therapeutic dose range is 500-1500 mg daily, which translates to 10-30 mL of the oral solution given in divided doses 3
• Gastrointestinal tolerance may differ between formulations—the enteric-coated divalproex sodium tablets historically showed better GI tolerance than valproic acid capsules, though this comparison has not been systematically studied with the liquid formulation 4