Vitamin B6
CAM (coenzyme in the synthesis of neurotransmitters, involved in neuronal myelin sheath formation; regulates glutamate; neuroprotective)
- SE-tremor1
- Premenstrual dysphoria3
- Mood problems on BCP
- May help depression
- Antipsychotic side effects: Akathisia1, tardive dyskinesia2, tremor, extrapyramidal side effects2, and prolactinemia1
Features
Dosing
Tremor, TD, akathisia, prolactinemia, tremor: 100-600 mg daily, divide bid (otherwise not fully absorbed).
Mood: 25-50 mg qd
For premenstrual syndrome, has a synergistic benefit with magnesium
To treat B6 deficiency caused by phenelzine or d-cycloserine: 10-25 mg qd.
Chronic use and high doses raises risk of neuropathy, especially above 1,000 mg. Use the active form of B6 (pyridoxal 5′-phosphate) to reduce neuropathy risk, and lower dose into safer range (50-100 mg) after 3-6 months on high dose.
All doses above are for the active form (pyridoxal 5-phosphate). If using standard B6 (pyroxidine), double the dose (these are approximate conversion factors).
Management
Vitamin B6 surpassed propranolol in treatment of akathisia and reduces other antipsychotic side effects. It reduced medication induced tremor in studies with valproate and lithium.
It may improve mood, based on small studies in premenses, women on estrogen, postpartum, and schizophrenia.
Main risk is neuropathy (reversible, presents as numbing, burning, tingling, or dyscoordination).
EMR Text
Akathisia
Vitamin B6 use based on multiple randomized controlled trials in akathisia (Shams-Alizadeh N et al, Iran J Pharm Res. 2018;17(Suppl):130-135).
Vitamin B6 risks, including neuropathy, reviewed with patient.
Tremor
Vitamin B6 use based on trials in medication-induced tremor (Dias Alves M et al, J Clin Psychopharmacol. 2017;37(2):267-269).
Vitamin B6 risks, including neuropathy, reviewed with patient.
Prolactinemia
Vitamin B6 use based on randomized controlled trials in antipsychotic-induced prolactinemia (Zhuo C et al, Front Psychiatry. 2021;12:681418).
Vitamin B6 risks, including neuropathy, reviewed with patient.
Tardive Dyskinesia
Vitamin B6 use based on a randomized controlled trial in antipsychotic-induced tardive dyskinesia (Lerner V et al, J Clin Psychiatry. 2007;68(11):1648-1654).
Vitamin B6 risks, including neuropathy, reviewed with patient.
Extrapyramidal side effects (EPS, Parkinsonism)
Vitamin B6 use based on multiple small randomized controlled trials where it improved extrapyramidal side effects of antipsychotics (Miodownik C et al, Harefuah. 2003;142(8-9):592-647).
Vitamin B6 risks, including neuropathy, reviewed with patient.
Premenstrual syndrome
Vitamin B6 use based on multiple small randomized controlled trials where it improved physical and psychological symptoms of premenstrual syndrome.
Vitamin B6 risks, including neuropathy, reviewed with patient.