REVIA Tablet Ref.[50411] Active ingredients: Naltrexone

Initiation of REVIA (naltrexone HCI) Therapy

DO NOT ATTEMPT TREATMENT WITH REVIA UNLESS, IN THE MEDICAL JUDGEMENT OF THE PRESCRIBING PHYSICIAN, THERE IS NO REASONABLE POSSIBILITY OF OPIOID USE WITHIN THE PAST 7-10 DAYS. IF THERE IS ANY QUESTION OF OCCULT OPIOID DEPENDENCE, PERFORM A NARCAN CHALLENGE TEST AND DO NOT ATTEMPT TO INITIATE REVIA THERAPY UNTIL NARCAN* CHALLENGE IS NEGATIVE (see below).

Treatment of Opioid Dependence

Initiate treatment with REVIA using the following guidelines:

1. Treatment should not be attempted until the patient has remained opioid-free for 7-10 days. Self-reporting of abstinence from opioids should be verified by analysis of the patient’s urine for absence of opioids. The patient should not be manifesting withdrawal signs or reporting withdrawal symptoms.
2. If there is any question of occult opioid dependence perform a NARCAN* challenge test (see below). If signs of opioid withdrawal are still observed following NARCAN* challenge, treatment with REVIA should not be attempted. The NARCAN* challenge can be repeated in 24 hours.
3. Treatment should be initiated carefully, slowly increasing the dose of REVIA administered. This can be accomplished by administration of 25 mg of REVIA initially. The patient should be observed for 1 hour. If no withdrawal signs occur, the patient may be given the rest of the daily dose.

Once the patient has been started on REVIA, 50 mg every 24 hours will produce adequate clinical blockade of the actions of parenterally administered opioids (i.e., this dose will block the effects of a 25 mg intravenous heroin challenge). A flexible approach to a dosing regimen may be employed in cases of supervised administration. Thus, patients may receive 50 mg of REVIA every weekday with a 100 mg dose on Saturday or patients may receive 100 mg every other day, or 150 mg every third day. While the degree of opioid blockade may be somewhat reduced by using higher doses at longer dosing intervals, improved patient compliance may result from dosing every 48-72 hours.

Several of the clinical studies reported in the literature have employed the following dosing regimen: 100 mg on Monday, 100 mg on Wednesday, and 150 mg on Friday. This dosing schedule appeared to be acceptable to many naltrexone patients successfully maintaining their opioid free state.

Treatment of Alcoholism

A dose of 50 mg once daily is recommended.

The placebo-controlled studies that demonstrated the efficacy of REVIA as an adjunctive treatment of alcoholism used a dose regimen of REVIA 50 mg once daily for up to 12 weeks. Other dose regimens or durations of therapy were not evaluated in these trials.

A patient is a candidate for treatment with REVIA if:

• the patient is willing to take a medicine to help with alcohol dependence;
• the patient is opioid free for 7-10 days;
• the patient does not have severe or active liver or kidney problems (typical guidelines suggest liver function tests no greater than three times the upper limits of normal, and bilirubin normal); and
• the patient is not allergic to REVIA, and no other contraindications are present.

Refer to CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS for additional information.

REVIA should be used as part of a comprehensive treatment program for alcohol dependence. Factors associated with a good outcome include: appropriate management of comorbid conditions; use of community-based support groups; and good medication compliance. To achieve the best possible treatment outcome, appropriate compliance enhancing techniques should be implemented for all components of the treatment program, especially medication compliance.

The efficacy of REVIA beyond twelve weeks of treatment has not been established.

NARCAN* CHALLENGE TEST

The NARCAN* challenge test should not be performed in a patient showing clinical signs or symptoms of opioid withdrawal, or in a patient whose urine contains opioids. The NARCAN* challenge test may be administered by either the intravenous or subcutaneous routes.

Intravenous: Inject 0.5 mL (0.2 mg) NARCAN* (0.4 mg/mL). Observe patient for 30 seconds for signs or symptoms of withdrawal. If there is no evidence of withdrawal, inject another 1.5 mL (0.6 mg) of NARCAN*. Observe patient for an additional 20 minutes.

Subcutaneous: Administer 2 mL (0.8 mg) NARCAN* (0.4 mg/mL). Observe patient for 20 minutes for signs or symptoms of withdrawal.

Note: Individual patients, especially those with opioid dependence, may respond to lower doses of NARCAN*. In some cases, 0.25 mL (0.1 mg) intravenous NARCAN* (0.4 mg/mL) has produced a diagnostic response.

Interpretation of the Challenge: Monitor vital signs and observe the patient for signs and symptoms of opioid withdrawal. These may include, but are not limited to: nausea, vomiting, dysphoria, yawning, sweating, tearing, rhinorrhea, stuffy nose, craving for opioids, poor appetite, abdominal cramps, sense of fear, skin erythema, disrupted sleep patterns, fidgeting, uneasiness, poor ability to focus, mental lapses, muscle aches or cramps, pupillary dilation, piloerection, fever, changes in blood pressure, pulse or temperature, anxiety, depression, irritability, back ache, bone or joint pains, tremors, sensations of skin crawling or fasciculations. If signs or symptoms of withdrawal appear, the test is positive and no additional NARCAN* should be administered.

Warning: If the test is positive, do NOT initiate REVIA therapy. Repeat the challenge in 24 hours (see Confirmatory rechallenge). If the test is negative, REVIA therapy may be started if no other contraindications are present. If there is any doubt about the result of the test, withhold REVIA and repeat the challenge in 24 hours (see Confirmatory rechallenge).

Confirmatorv rechallenge (if necessarv): Four (4) mL (1.6 mg) of NARCAN* (0.4 mg/ml) should be injected intravenously and the patient again observed for signs and symptoms of withdrawal. If none are present, REVIA may be administered. If signs and symptoms of withdrawal are present, administration of REVIA should be delayed until repeated NARCAN* challenge indicates the patient is no longer at risk.

Symptoms

There is limited clinical experience with REVIA (naltrexone hydrochloride) overdosage in humans. In one study, subjects who received 800 mg daily REVIA for up to one week showed no evidence of toxicity.

Treatment

Consideration should be given to contacting a poison control center for the most up-to-date information. In view of the lack of actual experience in the treatment of REVIA overdose, patients should be treated symptomatically in a closely supervised environment.

Store at controlled room temperature (15°-30°C). Dispense in a tight container as defined in the USP.