lorazepam (Ativan) - drug class, medical uses, medication side effects, and drug interactions by MedicineNet.com

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Medications and Drugs

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

GENERIC NAME: lorazepam

BRAND NAME: Ativan

DRUG CLASS AND MECHANISM: Lorazepam is a drug used for treating anxiety. It is in the benzodiazepine family, the same family that includes diazepam (Valium), alprazolam (Xanax), clonazepam (Klonopin), flurazepam (Dalmane), and others. It is thought that excessive activity of nerves in the brain may cause anxiety and other psychological disorders. Gamma-aminobutyric acid (GABA) is a neurotransmitter, a chemical that nerves in the brain use to send messages to one another. GABA reduces the activity of nerves in the brain. Lorazepam and other benzodiazepines may act by enhancing the effects of GABA in the brain. Because lorazepam is removed from the blood more rapidly than many other benzodiazepines, there is less chance that lorazepam concentrations in blood will reach high levels and become toxic. Lorazepam also has fewer interactions with other medications than most of the other benzodiazepines. The FDA approved lorazepam in March 1999.

PRESCRIPTION: Yes

GENERIC AVAILABLE: Yes

PREPARATIONS: Tablets: 0.5, 1, and 2 mg. Oral solution: 2 mg/ml. Injection: 2 mg/ml and 4 mg/ml

STORAGE: Tablets should be kept at room temperature 15-30°C (59-86°F). Oral solutions should be refrigerated at 2-8°C (36-46°F). Injectable solutions should be refrigerated.

PRESCRIBED FOR: Lorazepam is used for the management of anxiety disorders, the short-term relief of symptoms of anxiety or anxiety associated with depression. The effectiveness of lorazepam and other benzodiazepines has not been adequately studied for treatment beyond 4 months. Lorazepam is effective for insomnia, panic attacks, and is used in combination with other medications to prevent nausea and vomiting resulting from chemotherapy. Lorazepam also is administered before anesthesia and used for prevention and treatment of alcohol withdrawal.

DOSING: The dose of lorazepam is tailored to the patient's needs. The usual dose for treating anxiety is 2-3 mg/day given in two or three divided doses. Insomnia is treated with 2-4 mg given at bedtime.

DRUG INTERACTIONS: Lorazepam and all benzodiazepines interact with other medications and drugs that slow the brain's processes such as alcohol, barbiturates, narcotics, and tranquilizers. There have been cases of marked sedation when lorazepam was given to patients taking the tranquilizer loxapine (Loxitane); it is unclear if there is a drug interaction, but caution should be used if lorazepam and loxapine are used together.

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

NURSING MOTHERS: It is not known if lorazepam is secreted in breast milk.

SIDE EFFECTS: The most common side effects associated with lorazepam are sedation (15.9% of patients), dizziness (6.9% of patients), weakness, and unsteadiness. Other side effects include a feeling of depression, loss of orientation, headache, and sleep disturbance.

Like all benzodiazepines, lorazepam 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 lorazepam is taken continuously for longer than a few months, stopping therapy suddenly may produce seizures, tremors, muscle cramping, vomiting, and sweating.

Reference: FDA Prescribing Information

Last Editorial Review: 10/17/2007