According to a case report about a 24-year old woman ([PubMed Central][1]), in **agoraphobia,** during a panic attack, the sympathetic nervous system is activated, which results in adrenaline release, which causes symptoms, such as:

> ...headache, palpitations, pounding heart, jelly like legs, feelings
> of choking, shortness of breath, nervousness, dizziness, losing
> control on himself, feels detached from the surroundings **for few
> minutes.**

So, from symptoms lasting few minutes, you can conclude that adrenaline is acting for few minutes and not all the time.

According to one [2005 study][2], **caffeine** stimulates adrenaline release, but

> **adrenaline alone does not account for the effects of caffeine** and
> additional mechanisms must be involved.

Also, according to one [2015 review article][3]:

> moderate-to-high consumers develop tolerance to caffeine and **only low
> or nonconsumers can eventually benefit from an acute administration.**

In conclusion, if your buddy drinks a lot of coffee on a daily basis, she has probably developed tolerance to caffeine, in which case the wakening effect would be probably a placebo effect.

  [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3361850/
  [2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1464218/
  [3]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4462044/