Medications

Loss of Effectiveness and Dependence. Eventually these drugs can lose their effectiveness with continued use at the same dosage. As a result, patients may want to increase their dosage to prevent anxiety. This causes dependency, which can occur after as short a time as several weeks of taking these drugs. Some evidence suggests that the risk for abuse exists only in people who are already susceptible to substance abuse.

Withdrawal and its Treatments. Withdrawal symptoms can be very severe, even in people who rapidly discontinue benzodiazepines after taking them for only 4 weeks. Some experts believe that benzodiazepines are harder to withdraw from than heroin. Symptoms include sleep disturbance and anxiety, which can develop within hours or days after stopping the medication. Some patients experience stomach distress, sweating, and insomnia, which can last from 1 - 3 weeks. The longer the drugs are taken and the higher their dose, the more severe these symptoms can become. Simply tapering off gradually helps about 60% of people to withdraw. Certain medications (anti-seizure drugs, antidepressants, buspirone) may also be helpful in assisting with withdrawal.

Azapirones

Azapirones, such as buspirone (BuSpar) and gepirone (Ariza, Variza), act on serotonin receptors called 5-HT(1A). Buspirone has been the most intensively studied. It appears to work as well as a benzodiazepine for treating generalized anxiety disorder. It usually takes several days to weeks for the drug to be fully effective. It is not useful against panic attacks.

Buspirone does not produce any immediate euphoria or change in sensation, so some people believe, erroneously, that the drug doesn't work. Such qualities result in a very low potential for abuse. In fact, unlike the benzodiazepines, buspirone is not addictive, even with long-term use, so it may be particularly useful for the patient whose anxiety disorder coexists with alcoholism or drug abuse.

Buspirone also seems to have less pronounced side effects than benzodiazepines and no withdrawal effects, even when the drug is discontinued quickly. Common side effects include dizziness, drowsiness, and nausea. Buspirone should not be used with monoamine oxidase inhibitors (MAOIs).

Beta-Blockers

Beta-blockers, including propranolol (Inderal) and atenolol (Tenormin), block the nerves that stimulate the heart to beat faster. They affect only the physiologic symptoms of anxiety and are most helpful for phobias, particularly performance anxiety. Beta-blockers are less effective for other forms of anxiety.

Clonidine

Clonidine, a drug that relaxes blood vessels, has been used to treat children with post-traumatic stress disorder. Some experts believe it should be tried for anxiety disorders if other therapies fail. The drug can have severe side effects.

Atypical Antipsychotics

In certain severe cases, drugs called atypical antipsychotics may be useful. They include risperidone (Risperdal), olanzapine (Zyprexa), quetiapine (Seroquel), ziprasidone (Geodon), and others. In one study, risperidone was useful in combination with an SSRI for OCD patients who did not respond to an SSRI alone. They are also possibly useful for severe GAD. Common side effects include sleepiness and dizziness. Most cause weight gain. In high doses they may cause extrapyramidal symptoms, which involve the nerves and muscles controlling movement and coordination. The risk for these side effects, however, are far less than with older antipsychotic drugs. Still, there are many risks associated with all antipsychotic drugs. [For more information on antipsychotics, see In-Depth Report #47: Schizophrenia.]

Anticonvulsants

Pregabalin (Lyrica) and gabapentin (Neurontin) are drugs used to treat seizures and other conditions. Small studies suggest that these drugs may be useful for certain anxiety disorders, such as social phobia, general anxiety disorder, and post-traumatic stress disorder. A 2005 study suggested that pregabalin worked as well as the benzodiazepine alprazolam (Xanax) for treatment of generalized anxiety disorder.

Investigational Drugs

Glucocorticoids. Scientists are investigating whether the stress hormone cortisol can help reduce fear in people with phobias. In a preliminary research study, a cortisone drug helped reduce fear and anxiety in patients with social and spider phobias.