Acamprosate Calcium

Trade Names:Campral- Tablets, delayed-release 333 mg acamprosate calcium (equiv. to 300 mg acamprosate)

Pharmacology

Chronic alcohol exposure may alter normal balance between neuronal and excitation and inhibition. In vitro and in vivo animal data suggest acamprosate interacts with glutamate and GABA neurotransmitter systems, restoring this balance.

Pharmacokinetics

Absorption

Bioavailability about 11%. Steady state reached within 5 days. Steady-state concentrations average 350 ng/mL and occur 3 to 8 h postdose. C _max and AUC approximately 42% and 23%, respectively.

Distribution

Vd estimated to be 72 to 109 L (1 L/kg). Protein binding is negligible.

Metabolism

Does not undergo metabolism.

Elimination

Terminal t _½ ranges from about 20 to 33 h. Major route of excretion is via kidneys.

Special Populations

C _max in patients with moderate or severe renal function impairment were 2- and 4-fold higher, respectively. Elimination t _½ were 1.8- and 2.6-fold longer, respectively.

Indications and Usage

Maintenance of abstinence from alcohol in patients with alcohol dependence who are abstinent at treatment initiation.

Contraindications

Severe renal function impairment (Ccr 30 mL/min or less); hypersensitivity to any component of product.

Dosage and Administration

PO Two 333 mg tablets 3 times daily.

PO Start with 333 mg 3 times daily in patients with moderate renal function impairment (Ccr 30 to 50 mL/min). Do not administer to patients with severe renal function impairment (Ccr 30 mL/min or less).

Storage/Stability

Store tablets at controlled room temperature (59° to 86°F).

Drug Interactions

Weight gain and loss reported more frequently compared with either agent alone.

Acamprosate levels may be increased; however, no dosage adjustment is recommended.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Palpitation, syncope (at least 1%).

CNS

Insomnia (7%); asthenia, anxiety (6%); depression (5%); dizziness (3%); dry mouth, paresthesia (2%); headache, somnolence, decreased libido, amnesia, abnormal thinking, tremor, vasodilatation, hypertension (at least 1%).

Dermatologic

Pruritus (4%); sweating (2%); rash (at least 1%).

EENT

Pharyngitis, abnormal vision, taste perversion (at least 1%).

GI

Diarrhea (16%); nausea (4%); anorexia, flatulence (3%); vomiting, dyspepsia, constipation, increased appetite (at least 1%).

Genitourinary

Impotence (at least 1%); acute kidney failure (postmarketing).

Metabolic-Nutritional

Peripheral edema, weight gain (at least 1%).

Musculoskeletal

Back pain, myalgia, arthralgia (at least 1%).

Respiratory

Rhinitis, increased cough, dyspnea, bronchitis (at least 1%).

Miscellaneous

Accidental injury, pain (3%); abdominal pain, infection, flu syndrome, chest pain, chills, suicide attempt (at least 1%).

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Elderly

Because elderly are more likely to have decreased renal function, select dose with care and monitor renal function.

Renal Function

Reduce dose in patients with moderate renal function impairment. Do not administer to patients with severe renal function impairment (Ccr less than 30 mL/min).

Detoxification

Do not administer to patient who has not undergone detoxification or has not achieved alcohol abstinence.

Suicide

While infrequent, suicide is more common than in patients receiving placebo.

Withdrawal

Alcohol withdrawal symptoms are not eliminated or diminished by acamprosate administration.

Overdosage

Symptoms

Diarrhea.

Patient Information

• Ensure patient understands that acamprosate only helps maintain abstinence from alcohol and will not work if alcohol is still being ingested when therapy is started.
• Advise patient that medication will be most effective when taken exactly as prescribed and combined with participation in a comprehensive treatment program that includes counseling and support.
• Advise patient to take without regard to meals but to take with food if stomach upset occurs or if taking with food helps patient remember to take each dose.
• Advise patient to continue acamprosate therapy as directed, even in the event of a relapse. Instruct patient to discuss any renewed drinking with health care provider.
• Instruct family members and/or caregiver to monitor patient for development of symptoms of depression or suicidality often associated with alcohol dependence and to immediately inform health care provider if any symptoms of depression or suicidal behaviors or thoughts are noted.
• Advise patient that drug may impair judgment, thinking, or motor skills and to use caution while driving or performing other tasks requiring mental alertness and coordination until tolerance is determined.

Copyright © 2009 Wolters Kluwer Health.