What is the recommended dose of Nicotinamide Adenine Dinucleotide (NAD) for an adult patient?

NAD Dosing in Clinical Practice

For acute liver failure with suspected acetaminophen toxicity, N-acetylcysteine (NAC) should be administered at a loading dose of 150 mg/kg IV over 15 minutes, followed by 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours. 1

Critical Distinction: NAC vs. NAD

The evidence provided addresses N-acetylcysteine (NAC) for acetaminophen toxicity, not nicotinamide adenine dinucleotide (NAD) supplementation. These are entirely different compounds with distinct clinical applications.

NAC Dosing for Acetaminophen Toxicity

Intravenous Administration

• Loading dose: 150 mg/kg in 5% dextrose over 15 minutes 1
• Second dose: 50 mg/kg over 4 hours 1
• Third dose: 100 mg/kg over 16 hours 1
• NAC should be given as early as possible but may still provide benefit 48 hours or more after ingestion 1

Oral Administration

• Loading dose: 140 mg/kg by mouth or nasogastric tube (diluted to 5% solution) 1
• Maintenance: 70 mg/kg every 4 hours for 17 doses 1
• Oral administration may be precluded by active GI bleeding or altered mental status 1

Clinical Considerations

• NAC is recommended in any case of acute liver failure where acetaminophen overdose is suspected or possible, even without confirmed history 1
• Side effects are minimal with oral administration (occasional nausea, vomiting, rare urticaria or bronchospasm) 1
• Allergic reactions to IV NAC can be managed with discontinuation, antihistamines, and epinephrine for bronchospasm 1

NAD+ Precursor Supplementation (If This Was Your Intent)

Niacin/Nicotinamide (Vitamin B3)

• Daily requirement: Males >14 years: 16 mg/day; Females >14 years: 14 mg/day 1
• Parenteral nutrition: 40 mg/day 1
• Upper limit for nicotinamide: 12.5 mg/kg body weight/day (approximately 900 mg/day for adults) 1
• Upper limit for nicotinic acid: 10 mg/day for free nicotinic acid (though 3 g/day used clinically for hypercholesterolemia) 1

Emerging NAD+ Precursors (Research Context)

• Nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are being studied in clinical trials 2, 3
• Dosing regimens vary greatly across studies (NMN: 300-900 mg/day studied) 4
• These compounds are safe and tolerable but optimal dosing, administration routes, and long-term safety require further large-scale studies 3
• High interindividual variability exists in NAD+ response to supplementation 4