Syphilis patients who are allergic to both penicillin and cephalosporin can take tetracyclines and macrolides. Usually, syphilis can be treated by injections of penicillin or cephalosporins, two drugs that are preferred for the treatment of syphilis. However, many people may be allergic to penicillin and cephalosporin, then tetracyclines and macrolides can be chosen. As an alternative to antibiotics for people allergic to penicillin and cephalosporin, tetracyclines and macrolides are relatively less effective, but they can be used regularly and in sufficient quantities to achieve better results. Specific drugs are doxycycline, azithromycin, erythromycin and so on. However, syphilis spirochetes are extremely resistant to macrolides, so tetracyclines are preferred for these two types of drugs. However, it should be noted that syphilis patients taking drugs must be under the guidance of a doctor, it is strictly prohibited to take drugs privately, so as not to delay the condition caused by adverse consequences.