Relative with lung cancer was given Omeprazole 20 mg. once a day....

Relative with lung cancer was given Omeprazole 20 mg. once a day. On the second day, he started coughing up huge amounts of red blood which continued for hours and lessening throughout the day. That evening he questioned if the new prescription could have caused the bleeding and decided to discontinue its use. By the third day and since then (this is day six), no blood at all. None of my online searches suggested bleeding as a possible side effect.