Abdominal pain following intravenous benzyl penicillin administration.

The occurrence of abdominal pain (in three patients) and lower chest pain (in one patient) either during or immediately after the intravenous administration of high doses of benzyl penicillin is reported. All four patients were diagnosed as having bacterial endocarditis and had been receiving between 8 and 18 mega units of the drug per day for 2--3 weeks, when the symptoms were first noticed. A skin rash also appeared in each case, at this time. Both the rash and abdominal pain disappeared when an alternative antibiotic was substituted for the penicillin.