cardiovascular syphilis procaine penicillin 0.8 million U daily by intramuscular injection for 15 days,2 period of treatment Special care should be taken because a severe Jarisch-Herxheimer reaction fever,tachycardia,weaken the aortic wall,myocardial infarction prevention prednisone cardiovascular syphilis • procaine penicillin 0.8 million U daily by intramuscular injection for 15 days, 2 period of treatment • Special care should be taken because a severe Jarisch-Herxheimer reaction - fever, tachycardia, weaken the aortic wall, myocardial infarction - prevention prednisone