Pharmacy Author: Omudhome Ogbru, PharmD
Medical and Pharmacy Editor: Jay W. Marks, MD

GENERIC NAME: clonazepam

BRAND NAME: Klonopin

DRUG CLASS AND MECHANISM: Clonazepam is an anti-anxiety medication in the benzodiazepine family, the same family that includes diazepam (Valium), alprazolam (Xanax), lorazepam (Ativan), flurazepam (Dalmane), and others. Clonazepam and other benzodiazepines act by enhancing the effects of gamma-aminobutyric acid (GABA) in the brain. GABA is a neurotransmitter (a chemical that nerve cells use to communicate with each other) that inhibits brain activity. It is believed that excessive activity in the brain may lead to anxiety or other psychiatric disorders. Clonazepam also is used to prevent certain types of seizures.

PRESCRIPTION: Yes

GENERIC AVAILABLE: Yes

PREPARATIONS: Tablets: 0.5, 1, and 2 mg. Disintegrating tablets: 0.125, 0.25, 0.5, 1, and 2 mg.

STORAGE: Tablets should be kept at room temperature, between 15° and 30°C (59-86°F).

PRESCRIBED FOR: Clonazepam is used for the short-term relief of symptoms of anxiety. It is used for certain types of seizures, specifically petit mal seizures, akinetic seizures, and myoclonus, as well as Lennox-Gastaut syndrome. Clonazepam maybe used alone or together with other medications for these seizure disorders.

DOSING: The dose of clonazepam is tailored to the patient's needs. For seizures in adults the initial dose is 1.5 mg daily in 3 divided doses. Dosage may be increased by 0.5 to 1 mg daily every 3 days until seizures are controlled or side effects preclude further increases in dose. The maximum dose is 20 mg daily. The initial dose for panic disorders is 0.25 mg twice daily. The dose may be increased to the target dose of 1 mg daily after 3 days.

DRUG INTERACTIONS: Clonazepam, like all other benzodiazepines, accentuates the effects of other drugs that slow the brain's processes, such as alcohol, barbiturates, and narcotics and leads to increased sedation.

PREGNANCY: Clonazepam and other benzodiazepines have been associated with fetal damage, including congenital malformations, when taken by pregnant women in their first trimester. Clonazepam is best avoided in the first trimester and probably throughout pregnancy.

NURSING MOTHERS: Benzodiazepines are secreted in breast milk. Mothers who are breastfeeding should not take clonazepam.

SIDE EFFECTS: The most commonly noted side effects associated with clonazepam are sedation, which is reported in approximately half of patients, dizziness which is reported in one-third of patients, weakness, and unsteadiness. Other side effects include a feeling of depression, loss of orientation, headache, and sleep disturbance.

Like all benzodiazepines, clonazepam can cause physical dependence. Suddenly stopping therapy after a few months of daily therapy may be associated with a feeling of loss of self-worth, agitation, and insomnia. If clonazepam is taken continuously for longer than a few months, stopping therapy suddenly may produce seizures, tremors, muscle cramping, vomiting, and/or sweating. Therefore, discontinuation usually is accomplished by reducing the dose gradually.

Antiepileptic medications have been associated with an increased risk of suicidal thinking and behavior.  Anyone considering the use of antiepileptic drugs must balance this risk of suicide with the clinical need for the antiepileptic drug.  Patients who begin antiepileptic therapy should be closely observed for clinical worsening, suicidal thoughts or unusual changes in behavior.

Reference: FDA Prescribing Information