Dosing and uses of vitamin B6 (Antidote) (pyridoxine (Antidote))
Adult dosage forms and strengths
injectable solution
- 100mg/mL
tablets
- 25mg
- 50mg
- 100mg
- 200mg
- 250mg
- 500mg
tablets, sustained release
- 500mg
Isoniazid (INH) Overdose
1 g per gram INH ingested or 70 mg/kg IV if unknown, may require 1 g q30min; not to exceed 5 g with unclear history
Prevention of Drug-Induced Neuritis
10-50 mg/day PO (penicillamine or INH); 100-300 mg/day (cycloserine)
Ethylene Glycol Toxicity
100 mg IV q6hr for 2 days
Gyromitrin Poisoning
25 mg/kg IV infusion over 15-30 min; repeat PRN up to 15-20 g/day
Use in conjunction with benzodiazepines, phenobarbitaL
Other Indications & Uses
Toxicity due cycloserine OD, penicillamine OD, hydrazine ingestion, or Gyromitra mushrooms (contains monomethylhydrazine precursors)
May be effective in ginkgo biloba seed toxicity
Pediatric dosage forms and strengths
injectable solution
- 100mg/mL
tablets
- 25mg
- 50mg
- 100mg
- 200mg
- 250mg
- 500mg
tablets, sustained release
- 500mg
Isoniazid (INH) Overdose
1 g per gram INH ingested or 70 mg/kg IV if unknown, may require 1 g q30min, not to exceed 5 g with unclear history
Prevention of Drug-Induced Neuritis
1-2 mg/kg/24 hr PO
Ethylene Glycol Toxicity
1-2 mg/kg IV during first 24 hr
Gyromitrin Poisoning
25 mg/kg IV infusion over 15-30 min, repeat PRN up to 15-20 g/day
Use in conjunction with benzodiazepines, phenobarbitaL
vitamin B6 (Antidote) (pyridoxine (Antidote)) adverse (side) effects
Frequency not defined
Incoordination
Headache
Somnolence
Increased ASt
Ataxia
Neuropathy
Paresthesia
Seizures
Death in large doses
Delayed peripheral neurotoxicity long term
Pregnancy and lactation
Pregnancy category: A
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of vitamin B6 (Antidote) (pyridoxine (Antidote))
Mechanism of action
Shunts metabolism of ethylene glycol to nontoxic nonoxalates
Helps replete GABA depleted by INH or monomethylhydrazine
Administration
INH seizure: slow IV rate 0.5 g/min; remaining dose infused over 4-6 hr since seizure ceases to maintain pyridoxine avail. as INH metabolizes
Gyromitra: infuse over 15-30 min
