Fluoxetine, sertraline, fluvoxamine, paroxetine, and citalopram are among the SSRIs commonly prescribed for panic disorder, OCD, PTSD, and social phobia. SSRIs are often used to treat people who have panic disorder in combination with OCD, social phobia, or depression. Venlafaxine, a drug closely related to the SSRIs, is useful for treating GAD. Other newer antidepressants are under study in anxiety disorders, although one, bupropion, does not appear effective for these conditions. These medications are started at a low dose and gradually increased until they reach a therapeutic level.
Similarly, antidepressant medications called tricyclics are started at low doses and gradually increased. Tricyclics have been around longer than SSRIs and have been more widely studied for treating anxiety disorders. For anxiety disorders other than OCD, they are as effective as the SSRIs, but many physicians and patients prefer the newer drugs because the tricyclics sometimes cause dizziness, drowsiness, dry mouth, and weight gain. When these problems persist or are bothersome, a change in dosage or a switch in medications may be needed.
Tricyclics are useful in treating people with co-occurring anxiety disorders and depression. Clomipramine, the only antidepressant in its class prescribed for OCD, and imipramine, prescribed for panic disorder and GAD, are examples of tricyclics.
Monoamine oxidase inhibitors, or MAOIs, are the oldest class of antidepressant medications. The most commonly prescribed MAOI is phenelzine, which is helpful for people with panic disorder and social phobia. Tranylcypromine and isoprocarboxazid are also used to treat anxiety disorders. People who take MAOIs are put on a restrictive diet because these medications can interact with some foods and beverages, including cheese and red wine, which contain a chemical called tyramine. MAOIs also interact with some other medications, including SSRIs. Interactions between MAOIs and other substances can cause dangerous elevations in blood pressure or other potentially life-threatening reactions.
High-potency benzodiazepines relieve symptoms quickly and have few side effects, although drowsiness can be a problem. Because people can develop a tolerance to them — and would have to continue increasing the dosage to get the same effect-benzodiazepines are generally prescribed for short periods of time. One exception is panic disorder, for which they may be used for 6 months to a year. People who have had problems with drug or alcohol abuse are not usually good candidates for these medications because they may become dependent on them.
Some people experience withdrawal symptoms when they stop taking benzodiazepines, although reducing the dosage gradually can diminish those symptoms. In certain instances, the symptoms of anxiety can rebound after these medications are stopped. Potential problems with benzodiazepines have led some physicians to shy away from using them, or to use them in inadequate doses, even when they are of potential benefit to the patient. Benzodiazepines include clonazepam, which is used for social phobia and GAD; alprazolam, which is helpful for panic disorder and GAD; and lorazepam, which is also useful for panic disorder.
Buspirone, a member of a class of drugs called azipirones, is a newer anti-anxiety medication that is used to treat GAD. Possible side effects include dizziness, headaches, and nausea. Unlike the benzodiazepines, buspirone must be taken consistently for at least two weeks to achieve an anti-anxiety effect.