Medications for alcohol use disorders​

When to recommend medication

Primary care providers should routinely offer medication for moderate and severe alcohol use disorders, even if the patient is not willing to engage in formal psychosocial treatment.

Meta-analyses show that two medications, naltrexone and acamprosate, can reduce the frequency and intensity of binge drinking and increase abstinence rates (Baser et al., 2011; Jonas et al., 2014; Miller et al., 2011; Rösner et al., 2010a, 2010b). Studies show that disulfiram is only effective when a patient takes it under the supervision of a partner or pharmacist (Jorgensen et al., 2011).

Thiamine

Prescribing thiamine is important because heavy alcohol consumption can result in thiamine deficiency, which can lead to alcohol-induced brain damage.

Give thiamine to all patients who continue to drink or who are being treated for alcohol withdrawal. The appropriate dose is unclear from the evidence (Day et al,, 2013), but most physicians give at least 200 mg orally. Patients at higher risk of Wernikes encephalopathy should be given three days of intramuscular or intravenous thiamine.

Medications for managing alcohol use disorder

Three medications have been approved for treating patients with alcohol use disorders in primary care practice:

• naltrexone
• acamprosate
• disulfiram.

The actions and indications of these medications are outlined in Medications for AUD. Patient preference, side-effects, cost and availability will also influence the choice of medication.

Many Canadian provinces and territories require physicians to request coverage of naltrexone and acamprosate. For example, physicians in Ontario must submit a request through the Ministry of Health and Long-Term Care Exceptional Access Program (EAP).

Naltrexone

Naltrexone reduces heavy drinking and binge drinking, and helps patients achieve abstinence. It is the first-line medication. It can be prescribed while patients are still drinking.

Contraindications for naltrexone include opioid use and significant liver dysfunction.

Liver enzymes should be checked before initiating therapy and during treatment. Do not use naltrexone if liver enzymes are more than three times the upper limit of normal. Stop naltrexone if liver enzymes rise more than three times the patient's baseline.

The initial dose is 25 mg daily for three days (to minimize gastrointestinal upset), then 50 mg daily. The dose can be increased to a maximum of 150 mg per day if 50 mg daily is not effective.

In Ontario, EAP eligibility requires that patients have a diagnosis of alcohol dependence and are receiving counselling.

Acamprosate

Acamprosate is effective only in achieving abstinence, not in reducing heavy drinking. Patients must also have been abstinent for at least several days before beginning acamprosate.

Severe renal dysfunction is a contraindication to using acamprosate.

The dose is 666 mg three times a day. Moderate renal dysfunction and low body weight require a dose adjustment.

In Ontario, EAP eligibility requires that patients have a diagnosis of alcohol dependence, have been abstinent for at least four days, are receiving counselling and have contraindication to or side-effects with naltrexone.

Disulfiram

Disulfiram is effective in achieving abstinence if it is taken under supervision, for example by a pharmacist, partner or AA sponsor.

Use is contraindicated in patients who take metronidazole, who are elderly or pregnant or who have cardiac disease, liver dysfunction, psychosis or cognitive dysfunction.

Liver enzymes should be checked prior to initiating disulfiram, at two weeks and then every three months.

Patients must be abstinent for several days before beginning disulfiram and cannot drink while taking the medication. Reactions if the patient does drink can be severe.

Side-effects of disulfiram include hepatitis, neuropathy, depression and psychosis.

Disulfiram is no longer manufactured in Canada, so patients must obtain it from a compounding pharmacy or online.

Other medications

Several medications are used off-label to treat moderate or severe alcohol use disorder. These include topiramate, baclofen, ondansetron and gabapentin. The evidence base for these medications is much smaller and they are considered second-line medications. Gabapentin has evidence to support its use in the first six weeks of abstinence, which is the subacute withdrawal period.

The authors have attempted to ensure that the information on medication is accurate; however, physicians should check with the official drug monograph before prescribing any medication mentioned in this toolkit.

Encouraging patients to take medication as prescribed

Take an approach similar to that you would use to encourage patients to take SSRIs for depression:

• Emphasize that alcohol use disorders are  an illness with biological and psychological components.
• Emphasize that medication is an essential component of recovery for many patients.
• Ask about medication use at every visit.
• Ensure that the patient does not run out of medication.