Table 3:

Pharmacotherapy for alcohol use disorder^*^†

Characteristic	First-line options		Second-line options
Characteristic	Naltrexone	Acamprosate	Topiramate	Gabapentin
Efficacy	NNT to prevent return to heavy drinking is 12 (95% CI 8 to 26) (18) NNT to prevent return to any drinking is 20 (95% CI 11 to 500) (18) Reduced craving (Hedges’ g = 0.144 [small effect size], 95% CI 0.045 to 0.244) (19)	NNT to prevent return to any drinking is 12 (95% CI 8 to 26) (18) Increased days abstinent by 11 d (95% CI 5.08 to 16.81) (20)	Decreased heavy drinking days by 9.0% (95% CI −15.3% to −2.7%) (18) Decreased drinking days by 6.5% (95% CI −12.0% to −1.0%) (18) Increased the odds of maintaining abstinence up to 12 mo (OR 1.88, 95% CI 1.06 to 3.34) (21)	Decreased % heavy drinking days (Hedges’ g = 0.5478 [medium effect size], 95% CI 0.0145 to 1.0812) (21)
Concurrent alcohol use	Safe to start while using alcohol, but may be more effective after withdrawal management	Safe to start while using alcohol, but may be more effective after withdrawal management	Safe to start while using alcohol	Safe to start while using alcohol, but may be more effective if patients are abstinent for ≥ 3 d
Contra-indications	Naltrexone hypersensitivity Any current opioid use (prescribed or nonmedical) Acute opioid withdrawal Acute hepatitis or liver failure	Acamprosate hypersensitivity Severe renal impairment Breastfeeding	Topiramate hypersensitivity Pregnant or planning pregnancy Narrow-angle glaucoma Nephrolithiasis	Gabapentin hypersensitivity
Cautions	Renal impairment Severe hepatic impairment Concomitant use of other potentially hepatotoxic drugs Pregnancy and breastfeeding^† Youth patients aged < 18 yr^†	Moderate renal impairment Youth patients aged < 18 yr and older patients aged > 65 yr^† Pregnancy^†	Concomitant use of valproic acid Conditions or therapies that predispose to acidosis	Renal impairment Pregnancy and breastfeeding^† Youth patients aged < 18 yr and older patients aged > 65 yr^† Concomitant use of opioids and other central nervous system depressants Compromised respiratory function Neurological disease or cognitive impairment
Adverse effects	Nausea, headache and dizziness Starting at low dose or abstinence can reduce adverse effects	Diarrhea, vomiting and abdominal pain	Psychomotor slowing, difficulty concentrating, speech or language problems, somnolence, fatigue and mood disturbance Starting at low dose and titrating up can reduce adverse effects	Ataxia, slurred speech and drowsiness
Dosing	Start: 25 mg OD for 3 d Titrate: to 50 mg OD over 2 wk as tolerated	2 × 333 mg tablets TID	Titrate: to 2 × 50 mg tablets BID over several weeks as tolerated	Start: at 100–300 mg TID Titrate: PRN to 1800 mg max daily

Note: BID = twice daily, CI = confidence interval, NNT = number needed to treat, OD = once daily, OR = odds ratio, PRN = as needed or when necessary, TID = 3 times daily.
↵* There are limited data to support combination pharmacotherapy. Single-medication trials are suggested at first. Suggested duration is 6 months or longer. We gathered information for contraindications, cautions, adverse effects and dosage from the cited clinical trials and Health Canada–approved product monographs.
↵† Safety and efficacy have not been well established in these patient populations. Careful assessment of benefit and risks, fully informed patient consent and more frequent monitoring are advised.