Clonazepam

Brand names

• Alti-Clonazepam
• Apo-Clonazepam
• Clonapam
• Dom-Clonazepam
• Gen-Clonazepam
• Med-Clonazepam
• Novo-Clonazepam
• Nu-Clonazepam
• PMS-Clonazepam
• Rhoxal-Clonazepam
• Riva-Clonazepam
• Rivotril

Usage

To control seizures, and to treat panic disorder.

How it works

In general, clonazepam produces mild sedation by depressing activity in the central nervous system (the brain and spinal cord). In particular, clonazepam appears to enhance the effect of gamma-aminobutyric acid (GABA), a natural chemical that inhibits the firing of neurons and dampens the transmission of nerve signals, thus decreasing nervous excitation.

Side effects

Serious

Difficulty concentrating, outbursts of anger, other behavior problems, depression, hallucinations, low blood pressure (causing faintness or confusion), memory impairment, muscle weakness, skin rash or itching, sore throat, fever and chills, sores or ulcers in throat or mouth, unusual bruising or bleeding, extreme fatigue, yellowish tinge to eyes or skin.

Common

Drowsiness, loss of coordination, unsteady gait, dizziness, lightheadedness, slurred speech.

Less common

Change in sexual desire or ability, constipation, false sense of well-being, nausea and vomiting, urinary problems, unusual fatigue.

Possible interactions

Other medicaments:

Clonazepam taken concurrently with:

• amiodarone (Cordarone) may decrease elimination of clonazepam and also worsen toxicity by causing low thyroid function.
• carbamazepine (Tegretol) may decrease blood levels and hence benefits of both medications.
• desipramine, imipramine and other tricyclic antidepressants can decrease the tricyclic antidepressant blood level and lessen its therapeutic benefit.
• MAO inhibitors may result in very low blood pressure and worsening of sedation and respiratory depression.
• phenytoin (Dilantin) or fosphenytoin (Cerebyx) may result in decreased phenytoin or fosphenytoin levels.
• primidone (Mysoline) may lead to excessive drowsiness.
• ritonavir (Norvir), and perhaps other protease inhibitors, may lead to clonazepam toxicity.
• valproic acid (Depakene, etc.) may cause continuous absence seizures.

The following medicaments may increase the effects of clonazepam:



• antifungal medicines such as itraconazole (Sporanox) and ketoconazole (Nizoral).
• cimetidine (Tagamet).
• disulfiram (Antabuse).
• macrolide antibiotics such as azithromycin, clarithromycin or erythromycin.
• omeprazole (Prilosec).
• oral contraceptives (birth control pills).

The following medicaments may decrease the effects of clonazepam:



• rifampin (Rifater) or rifabutin (Mycobutin).
• theophylline (aminophylline, Theo-Dur, etc.).

Herbal medicines or minerals:

Hawthorn may react antagonistically to clonazepam. Valerian and kava kava may interact additively (drowsiness). Avoid these combinations. Kava and valerian may exacerbate central nervous system depression (avoid this combination). Kola nut, Siberian ginseng, mate, and ma huang may blunt the benefits of this medicine. While St. John's wort is indicated for anxiety, it is also thought to increase (induce) cytochrome P450 enzymes and will tend to blunt clonazepam effectiveness if combined with clonazepam.

Alcohol:

Alcohol may increase the depressant effects of this medicament on the brain. It is advisable to avoid alcohol completely throughout the day and night-if it is necessary to drive or to engage in any hazardous activity.

Marijuana smoking:

Increased sedation and significant impairment of intellectual and physical performance.

Discontinuation:

Do not stop clonazepam suddenly if it was controlling any type of seizure, or if it was taken for more than 4 weeks. Dosing should be slowly decreased (tapered) to prevent a withdrawal syndrome.