Mikhail Bulgakov said this quote

I must give due praise to the man who first extracted morphine from poppyheads. He was a true benefactor of mankind. The pain stopped seven minutes after the injection. Interesting: the pain passed over me in ceaseless waves, so that I had to gasp for breath, as though a red-hot crowbar were being thrust into my stomach and rotated. Four minutes after the injection I was able to distinguish the wave-like nature of the pain.