The two primary types of medications most often prescribed are SSRIs (selective seratonin reuptake inhibitors) and benzodiazepines. Traditionally, SSRIs are anti-depressants and benzos are anticonvulsants. Fortunately for most folks, they also help PA/PD (panic attack / panic disorder) sufferers like us.
Some examples of SSRIs include Prozac, Lexapro, Serzone, Celexa, Zoloft, and Paxil - among others. The general mechanism works the same for each, but with slightly different forumlation. Since SSRIs interact with your body/brain chemistry, what works for someone else might not work so well for you. There are also some nasty side effects which may or may not exhibit themselves. Lastly, SSRIs take awhile to build up an effective plasma saturation level - a month or two is normal. You usually "ramp up" dosages in one-week intervals until you're at a level that you find helpful. It's also not unusual to find that after a year or two on a specific SSRI, the benefits wane and you need to try another. Fortunately, you can typically cycle back to the one that worked after being on a couple others for a year or two. Fair warning though - do not stop taking an SSRI suddenly. They require a "ramp down" period. Suddenly dropping an SSRI can be a rather painful experience.
Some examples of benzos include Ativan, Klonopin, Librium, Valium and Xanax. Benzos work extremely quickly and have a relatively short half-life (extremely short, compared to SSRIs). They're quite helpful to most people if you suddenly find yourself having a panic attack and need to "reset your brain". That's the upside. The downside is that they can be highly addictive if you're predisposed to chemical dependency or have an addictive personality. I generally go with the rule that I take the absolute bare minimum dosage that'll get me through the panic attack and take them only as needed, never as a regular "maintenance medication". Arguably, the best and worst is Xanax. It can be incredibly helpful but it can also be incredibly addictive. At least according to the FDA-mandated information provided by the manufacturer, if you're on a daily dosage near or above 4mg, you need to "ramp down" your dosage prior to stopping the medication. Instances of seizures have been documented w