Valproate sodium IV

FDA label

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Titration Increase by 5-10 mg/kg/day at 1-week intervals

Renal Undefined

Hepatic Contraindicated in hepatic disease or significant hepatic dysfunction

Monitor more closely near 60 mg/kg/day, particularly without enzyme-inducing co-medication.

Instructions

• IV use only; infuse over 60 min at <=20 mg/min; dilute in >=50 mL compatible diluent (D5W, NS, LR — stable 24 h); discard unused vial contents
• Use beyond 14 days not studied — switch to oral valproate as soon as clinically feasible
• Replacement of oral therapy: same total daily dose and same frequency as oral product; monitor levels — with BID/TID IV dosing trough equivalence unproven (steady-state equivalence shown only q6h), monitor troughs closely
• Rapid infusion increases adverse reactions; single infusions up to 15 mg/kg over 5-10 min (1.5-3 mg/kg/min) were generally well tolerated in one safety study
• If total daily dose >250 mg, give in divided regimen
• Do not discontinue abruptly when preventing major seizures — risk of status epilepticus
• Conversion to monotherapy: reduce concomitant AED ~25% every 2 weeks
• Elderly: reduce starting dose, increase more slowly; monitor fluid/nutrition, somnolence
• On rufinamide: start valproate low and titrate to effect

Available strengths

• inj 100 mg/mL

Contraindications

• Hepatic disease or significant hepatic dysfunction
• Mitochondrial disorders caused by POLG mutations (e.g., Alpers-Huttenlocher); children <2 yr with suspected POLG-related disorder
• Urea cycle disorders
• Migraine prophylaxis: pregnancy, or childbearing potential without effective contraception

Cautions

• Hepatotoxicity, incl. fatal — monitor serum liver tests before and frequently during therapy (esp. first 6 mo); age <2 yr, polytherapy, metabolic/organic brain disease at highest risk
• Fetal risk: neural tube defects, major malformations, decreased IQ/neurodevelopmental disorders — avoid in women of childbearing potential unless other options failed; effective contraception + folate
• Pancreatitis, incl. fatal hemorrhagic — discontinue if diagnosed
• Hyperammonemic encephalopathy (evaluate for urea cycle disorders; risk increased with concomitant topiramate) — measure ammonia if unexplained lethargy/vomiting/mental-status change; hypothermia can co-occur
• Dose-related thrombocytopenia, coagulation abnormalities (low fibrinogen, acquired von Willebrand) — CBC + coags at baseline, periodically, before surgery, and in pregnancy
• Hypothermia (<35 C), with or without hyperammonemia
• DRESS/multiorgan hypersensitivity — discontinue
• Somnolence in the elderly — reduce starting dose, titrate slowly, monitor intake/dehydration
• Post-traumatic seizure prophylaxis: higher death rate with IV valproate vs IV phenytoin (13% vs 8.5%) in acute head-injury trial

Adverse reactions

• IV-specific: dizziness and injection-site pain (more frequent at faster infusion rates), injection-site reaction, taste perversion; discontinuations for nausea/vomiting and elevated amylase
• Plus all adverse reactions of oral valproate: nausea, somnolence, tremor, thrombocytopenia, alopecia, weight change, hyperammonemia

Pregnancy High teratogenicity: neural tube defects ~1-2% (registry major-malformation rate 9-11% at ~1,000 mg/day), craniofacial/cardiac/limb defects, hypospadias; decreased IQ, ASD/ID/ADHD risk; dose-dependent, no safe threshold. Contraindicated for migraine prophylaxis; epilepsy/bipolar only if other drugs failed. Do not stop abruptly (status epilepticus). Folate + NAAED registry (1-888-233-2334).

Lactation Excreted in milk at 1-10% of maternal serum levels (infant serum 0.7-4 mcg/mL, 1-6% of maternal); no adverse developmental/cognitive effects reported through age 6. Monitor breastfed infant for jaundice and unusual bruising/bleeding (hepatic failure and clotting abnormalities reported in valproate-exposed offspring).