The following convention has been utilised for the classification of undesirable effects:- Very common (>1/10), common (>1/100, <1/10), uncommon (>1/1000, <1/100), rare (>1/10,000, <1/1000), very rare ( <1/10,000).
Unless otherwise stated, the frequency of the adverse events has been derived from more than 30 years of post-marketing reports.
Blood and lymphatic system disorders
Very rare: Neutropenia (including agranulocytosis) and thrombocytopenia. These are reversible when treatment is discontinued. Haemolytic anaemia.
Immune system disorders
Very rare: Anaphylactic shock (exceptional with oral administration) (see Item 4.4 Warnings), angioneurotic oedema.
If any hypersensitivity reaction occurs, the treatment should be discontinued. (See also Skin and subcutaneous tissue disorders).
*Common: Minor gastrointestinal disturbances.
Very rare: Pseudomembranous colitis.
If pseudomembranous colitis develops, flucloxacillin treatment should be discontinued and appropriate therapy, e.g. oral vancomycin should be initiated.
Very rare: Hepatitis and cholestatic jaundice. Changes in liver function laboratory test results (reversible when treatment is discontinued).
These reactions are related neither to the dose nor to the route of administration. The onset of these effects may be delayed for up to two months post-treatment; in several cases the course of the reactions has been protracted and lasted for some months. Hepatic events may be severe and in very rare circumstances a fatal outcome has been reported. Most reports of deaths have been in patients ≥ 50 years and in patients with serious underlying disease.
Skin and subcutaneous tissue disorders
*Uncommon: Rash, urticaria and purpura.
Very rare: Erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis.
(See also Immune system disorders).
Musculoskeletal and connective tissue disorders
Very rare: Arthralgia and myalgia sometimes develop more than 48 hours after the start of the treatment.
Renal and urinary disorders
Very rare: Interstitial nephritis.
This is reversible when treatment is discontinued.
General disorders and administration site conditions
Very rare: Fever sometimes develops more than 48 hours after the start of the treatment.
*The incidence of these AEs was derived from clinical studies involving a total of approximately 929 adult and paediatric patients taking flucloxacillin.