Common adverse drug reactions (ADRs) associated with the use of dicloxacillin include: diarrhea, nausea, rash, urticaria, pain and inflammation at injection site, superinfection (including candidiasis), allergy, and transient increases in liver enzymes and bilirubin.
On rare occasions, cholestatic jaundice (also referred to as cholestatic hepatitis) has been associated with dicloxacillin therapy. The reaction may occur up to several weeks after treatment has stopped, and takes weeks to resolve. The estimated incidence is 1 in 15,000 exposures, and is more frequent in people over 55 years old, females, and those with treatment longer than 2 weeks.
It should be used with caution and monitored in the elderly, particularly with intravenous administration, due to a risk of thrombophlebitis.
Dicloxacillin can also lower the effectiveness of birth control pills and pass into breast milk.