Taking different types of antibiotics has its corresponding precautions. Penicillin If you have had a previous allergic reaction to penicillins, it is recommended that you do not use all types of penicillins, as all may produce an allergic reaction. People with a history of rare medical conditions, such as asthma, eczema or hay fever allergies, are at higher risk of severe allergic reactions to penicillin. Penicillin may need to be used at a lower dose if you have conditions such as severe kidney disease, liver disease, etc. During pregnancy and breastfeeding, you can take most penicillins at their regular doses. It is recommended that you consult your doctor in the relevant department so that they can prescribe the most appropriate antibiotic for you. Cephalosporins If you have had a previous allergic reaction to penicillin, you may also be allergic to cephalosporins. If you have severe kidney disease, cephalosporin may not be suitable, but if it is necessary, a lower dose is recommended. If you are pregnant or breastfeeding, consult your doctor before taking cephalosporins. Aminoglycosides Aminoglycosides are usually only used in hospitals to treat life-threatening health conditions, such as sepsis, because they can cause serious damage to people with pre-existing kidney disease and are generally not recommended during pregnancy. Tetracyclines Tetracyclines are not usually recommended unless they are necessary in the following situations: People with severe kidney disease, except doxycycline may be used People with severe liver disease People with lupus who have an autoimmune disease Children under 12 years of age Pregnant or breastfeeding women Macrolides Do not take macrolides if you have porphyria, a rare genetic blood disorder. If you are pregnant or breastfeeding, the only macrolide you can take is erythromycin, unless your doctor recommends another antibiotic. You can take erythromycin at your regular dose throughout your pregnancy and while breastfeeding. No other macrolides should be used during pregnancy unless recommended by a specialist. Fluoroquinolones Fluoroquinolones are usually not suitable for pregnant or breastfeeding women.