6.5 Antianxiety Medications

Antianxiety medications help reduce the symptoms of anxiety, panic attacks, or extreme fear and worry. The most common class of antianxiety medications is benzodiazepines. Benzodiazepines are used to treat generalized anxiety disorder, although SSRIs or other antidepressants are typically used to treat panic disorder or social phobia (i.e., social anxiety disorder). Beta-blockers and buspirone may also be prescribed for anxiety.^[1]

Benzodiazepines

Benzodiazepines are used to treat anxiety and are also used for their sedation and anticonvulsant effects because they bind to GABA receptors and stimulate the effects of GABA (an inhibitory neurotransmitter). Benzodiazepines include clonazepam, alprazolam, and lorazepam. Benzodiazepines are a Schedule IV controlled substance because they have a potential for misuse and can cause dependence. Short-acting benzodiazepines (such as lorazepam) and beta-blockers are used to treat the short-term symptoms of anxiety. Lorazepam is available for oral, intramuscular, or intravenous routes of administration.^[2]

If people suddenly stop taking benzodiazepines after taking them for a long period of time, they may have withdrawal symptoms, or their anxiety may return. Withdrawal symptoms include sleep disturbances, irritability, increased tension and anxiety, hand tremors, sweating, difficulty concentrating, nausea and vomiting, weight loss, palpitations, headache, muscular pain, and perceptual changes.^[3] Therefore, benzodiazepines should be tapered off slowly.^[4]

Overdosage of Benzodiazepines

Overdosage of benzodiazepines is manifested by varying degrees of central nervous system depression, ranging from drowsiness to coma. If overdose occurs, call 911 or the rapid response team during inpatient care. Treatment of overdosage is mainly supportive until the drug is eliminated from the body. Vital signs and fluid balance should be carefully monitored in conjunction with close observation of the client. An adequate airway should be maintained; intubation and mechanical ventilation may be required. The benzodiazepine antagonist flumazenil may be used to manage benzodiazepine overdose. There is a risk of seizure in association with flumazenil treatment, particularly in chronic users of benzodiazepines.

Side Effects

Overdosage of benzodiazepines causes central nervous system depression, ranging from drowsiness to coma. Children and older adults are more susceptible to the sedative and respiratory depressive effects of lorazepam and may experience paradoxical reactions such as tremors, agitation, or visual hallucinations. Benzodiazepines may cause fetal harm when administered to pregnant women. There is a boxed warning that concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. See Table 6.5 for summarized information about benzodiazepines.

Table 6.5. Benzodiazepines

Black Box Warning

A Black Box Warning states that concurrent use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. The use of benzodiazepines exposes users to risks of misuse, substance use disorder, and addiction. Misuse of benzodiazepines commonly involves concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes. Additionally, the continued use of benzodiazepines may lead to clinically significant physical dependence. The risks of dependence and withdrawal increase with longer treatment duration and higher daily doses, and abrupt discontinuation or rapid dosage reduction may precipitate life-threatening withdrawal reactions. To reduce the risk of withdrawal reactions, a gradual taper should be used to stop or reduce the dosage.^[5]

Client Education

Clients should be cautioned that driving a motor vehicle, operating machinery, or engaging in hazardous or other activities requiring attention and coordination should be delayed for 24 to 48 hours following administration of benzodiazepines or until the effects of the drug, such as drowsiness, have subsided. Alcoholic beverages should not be consumed for at least 24 to 48 hours after receiving lorazepam due to the additive effects on central nervous system depression. Hospitalized clients should be advised that benzodiazepines increase fall risk, and getting out of bed unassisted may result in falling and potential injury.

Beta-Blockers

Beta-blockers, such as propranolol, are medications that block the effects of the sympathetic nervous system by acting on Beta-1 receptors in the heart and other areas of the body. While they are most commonly prescribed to treat high blood pressure, heart rhythm disorders, and other cardiac conditions, beta-blockers may also be used off-label to help manage the physical symptoms of anxiety—such as trembling, rapid heartbeat, and sweating—especially in short-term or situational anxiety, such as public speaking or test anxiety. In these cases, they are often prescribed “as needed” rather than for continuous daily use. They may be prescribed to manage the physical symptoms of anxiety (such as trembling, rapid heartbeat, and sweating) for a short period of time or used “as needed” to reduce acute physical symptoms.^[6]

Common side effects of beta-blockers are fatigue, hypotension, dizziness, weakness, and cold hands. Beta-blockers are typically avoided in clients with asthma or diabetes.^[7]

Buspirone

Buspirone is a non-benzodiazepine medication indicated for the treatment of chronic anxiety. It is included in the class of medications called anxiolytics, but it is not chemically related to benzodiazepines, barbiturates, or other sedatives. Buspirone should not be taken concurrently with a monoamine oxidase inhibitor (MAOI) due to the risk of fatal side effects. It can also cause serotonin syndrome if used in combination with MAOIs, SSRIs, or SNRIs.^[8]

Buspirone increases serotonin and dopamine levels in the brain. In contrast to benzodiazepines, buspirone must be taken every day for a few weeks to reach its full effect; it is not useful on an “as-needed” basis. A common side effect of buspirone is dizziness.^[9]Buspirone is non-addictive and safer for long-term use than benzodiazepines.

Hydroxyzine

Hydroxyzine is type of antihistamine which may be prescribed to alleviate anxiety for individuals for whom benzodiazepines are not appropriate. It causes sedation, so it must be used cautiously if used in combination with opioids or barbiturates. Hydroxyzine is recommended for short-term use in the treatment of anxiety and tension. The effectiveness of hydroxyzine for long-term use, defined as more than 4 months, has not been systematically assessed in clinical studies. Therefore, it is advised that physicians periodically reassess the usefulness of the drug for each individual client.^[10]