What is the Difference Between Cloxacillin and Flucloxacillin?

The main difference between cloxacillin and flucloxacillin lies in their absorption, elimination time, and serum concentrations:

1. Absorption: Flucloxacillin has a better oral absorption (53.7%) compared to cloxacillin (32.9%). This results in higher serum concentrations after oral administration of flucloxacillin.
2. Elimination Time: Flucloxacillin has a slower elimination time (half-life of 46 minutes) compared to cloxacillin (half-life of 32 minutes). This contributes to the higher serum concentrations achieved by flucloxacillin.
3. Serum Concentrations: Flucloxacillin produces higher total and free serum levels than cloxacillin when administered orally or intramuscularly. Additionally, the extent of binding of flucloxacillin to human serum protein is similar to that of cloxacillin.

Both cloxacillin and flucloxacillin are antibiotics used to treat bacterial infections, but due to the differences mentioned above, flucloxacillin may be more effective in certain situations. However, it is essential to consider the specific clinical context and the susceptibility of the bacteria involved before choosing the appropriate antibiotic for treatment.

Comparative Table: Cloxacillin vs Flucloxacillin

Cloxacillin and Flucloxacillin are both antibiotics belonging to the penicillin group, but they have some differences in their properties and characteristics. Here is a table comparing the two:

Both cloxacillin and flucloxacillin are used to treat various bacterial infections, such as skin infections, external ear infections, and infections of leg ulcers. They work by breaking down the bacterial cell wall and are more acid-stable than many other penicillins, which allows them to be given orally in addition to parenteral routes. However, cloxacillin has a comparatively higher absorption and faster elimination compared to flucloxacillin. There are also differences in protein binding between the two drugs. Despite these differences, the two agents are considered interchangeable and have similar pharmacokinetics, antibacterial activity, and indications.