List of adverse effects of valproic acid explained

List of adverse effects of valproic acid by frequency:^[1] ^[2] ^[3] ^[4]

Very common (>10%)

Nausea
Vomiting
Diarrhea
Headache
Low platelet count (dose-related)
Tremor (dose-related)
Hair loss (usually temporary)
Drowsiness
Dizziness
Hyperandrogenism in females
Seeing double
Indigestion
Lazy eye
Infection
Tinnitus

Elevated aminotransferase concentrations (dose-related; indicative of liver injury)

Common (1-10%)

Paresthesia
Abdominal pain
Tremor
Increased appetite
Weight gain
Ataxia
Polycystic ovaries
Memory impairment
Menstrual irregularities
Rash
Back pain
Mood changes
Anxiety
Confusion
Abnormal gait
Hallucinations
Catatonia
Dysarthria
Tardive dyskinesia
Vertigo

High blood levels of ammonia without symptoms

Uncommon (0.1-1%)

Peripheral edema
Syndrome of inappropriate secretion of antidiuretic hormone

Rare (<0.1% frequency)

Liver failure
Pancreatitis (these two usually occur in first 6 months and can be fatal)
Leukopenia (low white blood cell count)
Neutropenia (low neutrophil count)
Pure red cell aplasia
Agranulocytosis
Extrapyramidal syndrome (including parkinsonism, may be reversible)
Brain problems due to high ammonia levels
Low body temperature
Hypersensitivity reactions including multi-organ hypersensitivity syndrome
Eosinophilic pleural effusion
Bone fractures (reduced BMD with long-term use)

Notes and References

Web site: Depakene, Stavzor (valproic acid) dosing, indications, interactions, adverse effects, and more. Medscape Reference. WebMD. 13 February 2014.
Book: Australian Medicines Handbook . 2013 . The Australian Medicines Handbook Unit Trust . 978-0-9805790-9-3 . 2013 . Adelaide . Rossi, S .
Book: Joint Formulary Committee . British National Formulary (BNF) . 978-0-85711-084-8 . 65 . London, UK . Pharmaceutical Press . registration .
Web site: Valpro sodium valproate. TGA eBusiness Services. Alphapharm Pty Limited. 16 December 2013. 14 February 2014. PDF.