Xanax, also known by its generic name alprazolam, is a benzodiazepine, and is used to treat anxiety disorders such as panic disorder. Benzodiazepines modulate GABA receptors, which have inhibitory effects on the CNS (Central Nervous System). The problem with Xanax, as with all the benzodiazepines, is that there is an addictive potential when taking this medication.
Although Xanax is highly effective for eliminating panic attacks as it has a fast onset of action, it is also potentially addictive. You can develop tolerance to the effects of Xanax, meaning you need more and more of the Xanax to get the same clinical effect of anxiety relief. Another problem with Xanax is that it has a short duration of action, so you can develop rebound symptoms in between doses, which is a result of the blood levels of the Xanax dropping suddenly. These rebound symptoms can take the form of worsening panic attacks, so the symptom you are trying to treat may actually get worse when the blood level drops between doses.
This is why I do not recommend Xanax for panic disorder, as it has a short duration of action and has potential problems with rebound symptoms. And even worse may be when you miss doses of Xanax, then you might develop withdrawal symptoms of anxiety, irritability, trembling, sweating, nausea and fatigue. These withdrawal symptoms then may foster dependence on the Xanax, as you need to keep taking the drug to prevent the withdrawal symptoms.
These withdrawal and rebound symptoms associated with Xanax can be avoided by not taking Xanax at all…if a benzodiazepine needs to be prescribed for immediate relief of panic attacks, then the best choice for a benzodiazepine is long-acting Klonopin (clonazepam). And even if you do take Klonopin, your doctor will have prescribed an SSRI (Selective Serotonin Reuptake Inhibitor) concurrently, then eventually taper and discontinue the Klonopin when the SSRI becomes effective for panic disorder weeks later. Benzodiazepines are rarely prescribed alone as a treatment for panic disorder.
If you must take Xanax (although I highly recommend NOT taking Xanax), then it can be started at 0.5mg three times daily for panic disorder. It can be increased to 1mg three times daily if needed. Again, I do not recommend that you start Xanax, as it is associated with withdrawal and rebound symptoms, and has a high abuse potential. Klonopin is the benzodiazepine of choice to start concurrently with an SSRI for treatment of panic disorder, given its long duration of action and less propensity for withdrawal and rebound symptoms when compared to Xanax. And when the SSRI becomes effective weeks later, then the Klonopin can be tapered and discontinued.
The take home message is that Xanax is a poor choice for panic disorder, and if a benzodiazepine must be prescribed, then Klonopin is the best choice. SSRIs are still the 1st line treatment for panic disorder. Benzodiazepines are almost never prescribed alone for panic disorder, given the effectiveness of SSRIs.