Ibn Abbas (May Allah be pleased with them) said: The Messenger of Allah (PBUH) used to say when he was in distress:

"La ilaha illallahul-Azimul-Halim. La ilaha illallahu Rabbul-`Arshil-`Azim. La ilaha illallahu Rabbus-samawati, wa Rabbul-ardi, wa Rabbul-`Arshil-Karim.

(None has the right to be worshipped but Allah the Incomparably Great, the Compassionate. None has the right to be worshipped but Allah the Rubb of the Mighty Throne. None has the right to be worshipped but Allah the Rubb of the heavens, the Rubb of the earth, and the Rubb of the Honourable Throne).'' [Al-Bukhari and Muslim].

The only medicine in a time of distress is the remembrance of Allah Whose Help alone should be sought. This Duaa contains words which glorify Allah and exalt Him far above all else. It is desirable to recite these words when one is in distress as this is exactly what the Prophet (PBUH) used to recite in such situations.