Floxacillin is the recommended antibiotic for recurrent boils and carbuncles, according to the NHS website. For those who have allergies to penicillin, alternatives are erythromcyin or clarithromycin.
Boils do not usually need antibiotics unless they are recurrent. This could mean that the Staphylococcus aureus bacteria is present, and this needs to be treated. Common places for boils, as outlined by WebMD, are on the face and on parts of the body where there is hair or rubbing, such as the armpits. It is recommended not to lance a boil yourself. This should be done by a doctor or a nurse.