Panic attacks are miserable. I had them when I was younger. Two things helped me get through them. First, the realization that despite the physical symptoms I was not suffering from a heart attack or anything that was actually endangering my health. Second, a panic attach is time limited and will end, usually in under ten minutes. Though some can go on for hours, mine lasted five to ten minutes.
I liked the recommendations from nurseleah. See a therapist for counseling and psychiatrist for medications. Though medication is not always necessary.
I would add a recommendation to have a physical to eliminate any medical problems. The good news for your friend is the prognosis for panic attacks is very good, most people have a full recovery.