Acamprosate Dosing: 666 mg Three Times Daily
Yes, acamprosate is dosed as 666 mg (two 333 mg delayed-release tablets) taken three times daily for most patients. This is the FDA-approved standard dosing regimen for maintaining alcohol abstinence 1.
Standard Dosing Regimen
- Standard dose: 666 mg (two 333 mg tablets) three times daily, totaling 1,998 mg/day 1
- Formulation: Enteric-coated delayed-release tablets 1, 2
- Timing: Can be taken without regard to meals, though dosing with meals was used in clinical trials and may be suggested for patients who regularly eat three meals daily 1
- Treatment initiation: Should begin as soon as possible after alcohol withdrawal period, once patient has achieved abstinence 1
Dose Adjustments
Body Weight Considerations
- Patients ≥60 kg: 1,998 mg/day (666 mg three times daily) 3
- Patients <60 kg: Reduced by one-third to approximately 1,332 mg/day 3, 4
Renal Impairment
- Moderate renal impairment (creatinine clearance 30-50 mL/min): Reduced dose of 333 mg (one tablet) three times daily 1
- Severe renal impairment (creatinine clearance ≤30 mL/min): Contraindicated 1
Pharmacokinetic Profile
- Steady-state: Reached after 5-7 days of repeated dosing 2
- Plasma concentrations at steady-state: 370-650 mcg/L with 666 mg three times daily 2
- Elimination half-life: Approximately 3 hours after IV administration, but longer with enteric-coated tablets due to flip-flop kinetics 2
- Metabolism: Not metabolized; excreted unchanged in urine (50%) and possibly via biliary excretion (50%) 2
- Protein binding: None 2
Clinical Context
Acamprosate should be used as part of comprehensive psychosocial treatment programs 1. The medication works as an NMDA receptor antagonist to reduce withdrawal effects and alcohol craving 5. Importantly, acamprosate has no hepatic metabolism and no reported instances of hepatotoxicity, making it particularly suitable for patients with alcohol-associated liver disease 5.
Common Pitfalls
- Food interaction: Concomitant administration with food decreases absorption 2, though clinical trials dosed with meals 1
- Renal function monitoring: Essential to assess before initiation and during treatment, as renal insufficiency significantly affects elimination 2
- Continuation during relapse: Treatment should be maintained even if patient relapses 1
- Treatment duration: Typically 3-6 months, though the optimal duration continues to be studied 3