Lorazepam
Definition
Lorazepam, a mild tranquilizer in the class of drugs known as benzodiazepines is a sold in the United States under brand names Alzapam, Ativan, or Loraz. It is also available generically.
Purpose
Lorazepam is used for management of anxiety, nausea and vomiting, insomnia , and seizures . Lorazepam is also used prior to surgery to produce sedation, sleepiness, drowsiness, relief of anxiety, and a decreased ability to recall the events surrounding the surgery.
Description
Lorazepam is a member of the benzodiazepine family. Benzodiazepines primarily work by enhancing the function of a certain naturally occurring brain chemical, gamma aminobutyric acid (GABA), that is responsible for inhibiting the transmission of nervous impulses in the brain and spinal cord. At the same time, the enhancement of GABA in the brain decreases symptoms associated with anxiety. Lorazepam differs from drugs such as diazepam (Valium) and chlordiazepoxide (Librium) in that it is shorter acting and does not accumulate in the body after repeated doses.
Lorazepam is available in 0.5-mg, 1-mg, and 2-mg tablets and in an injectable form.
Recommended dosage
Lorazepam is taken several times daily by mouth or injected to treat anxiety. Dosage ranges from 1–2 mg taken either every 12 or every eight hours. The maximum daily total dosage for anxiety is 10 mg given in two to three divided doses. For sleep, patients may take from 2–4 mg at bedtime. Doses taken before surgery range from 2.5–5 mg.
Between 0.5 mg and 1 mg of lorazepam may be taken every six to eight hours to help control treatment-related nausea and vomiting (nausea and vomiting that occur as a side effect of a drug or medical treatment). Two mg of lorazepam is often given half an hour before chemotherapy to help prevent stomach upset. An additional 2 mg may be taken every four hours as needed.
The usual dose to treat seizures is 4 mg given intravenously (through a vein). This dose may be increased to 8 mg in patients who do not respond to the 4-mg dose.
Precautions
Lorazepam, like other drugs of this type, can cause physical and psychological dependence. Patients should not increase the dose or frequency of this drug on their own, nor should they suddenly stop taking this medication. Instead, when stopping the drug, the dosage should gradually be decreased, then discontinued. If the drug is stopped abruptly, the patient may experience agitation, irritability, difficulty sleeping, convulsions, and other withdrawal symptoms.
Patients allergic to benzodiazepines should not take lorazepam. Those with narrow-angle glaucoma, pre-existing depression of the central nervous system, severe uncontrolled pain, or severe low blood pressure should not take lorazepam. This drug should be used with caution in patients with a history of drug abuse. Children under age 12 should not take lorazepam. Children between the ages of 12 and 18 may take the drug by mouth, but not intravenously. Pregnant women and those trying to become pregnant should not take lorazepam. This drug has been associated with damage to the developing fetus when taken during the first three months of pregnancy. Patients taking this drug should not breast-feed.
Side effects
Drowsiness and sleepiness are common and expected effects of lorazepam. Patients should not drive, operate machinery, or perform hazardous activities that require mental alertness until they have a sense of how lorazepam will affect their alertness. Patients over age 50 may experience deeper and longer sedation after taking lorazepam. These effects may subside with continued use or dosage reduction.
The effects of an injection may impair performance and driving ability for 24–48 hours. The impairment may last longer in older people and those taking other central nervous system depressants, such as some pain medications.
Lorazepam may also make patients feel dizzy, weak, unsteady, or clumsy. Less frequently, people may feel depressed, disoriented, nauseous, or agitated while taking this drug. Other side effects include headache, difficulty sleeping, rash, yellowing eyes, vision changes, and hallucinations . Redness and pain may occur at the injection site.
Patients may experience high or low blood pressure and difficulty breathing after an injection of lorazepam. Nausea, vomiting, dry mouth, and constipation may also occur. The patient's sex drive may decrease, but this side effect is reversible once the drug is stopped. Patients should alert their physician to confusion, depression, excitation, nightmares, impaired coordination, changes in personality, changes in urinary pattern, chest pain, heart palpitations, or any other side effects.
Interactions
Alcohol and other central nervous system depressants can increase the drowsiness associated with this drug. Some over-the-counter medications depress the central nervous system. The herbal remedies kava kava and valerian may increase the effects of lorazepam. Patients should check with a doctor before starting any new medication while taking lorazepam. People should not drink alcoholic beverages when taking lorazepam and for 24–48 hours before receiving an injection prior to surgery.
Resources
BOOKS
Gilman, Alfred G. The Pharmacological Basis of Therapeutics. New York: McGraw-Hill, 1996.
Kaplan, Harold. Comprehensive Textbook of Psychiatry. ladelphia: Lippincott, Williams and Wilkins, 1995.
Lacy, Charles F. Drug Information Handbook. Lexi-Comp, Inc. 2002.
Debra Wood, R.N. Ajna Hamidovic, Pharm.D.