Augmentin VS Unasyn

Augmentin VS Unasyn

Augmentin (Amoxicillin + Clavulanic Acid) and Unasyn (Ampicillin + Sulbactam) are both belong to the penicillin class of aminopenicillin group. Both of them are used to treat urinary tract infections (UTI), otitis media, bacteria that include Haemophilus influenza, Salmonella and Listeria meningitis.

Clavulanic acid and sulbactam are beta lactamase inhibitor which used in combination with penicillin with the purpose to enhance the stability of the drugs toward beta lactamase producing bacteria.

The difference we can observe from these 2 drugs would be their mechanism of action. Amoxicillin works by cross linking the linear peptidoglycan polymer chains that forming the cell wall of bacteria (both gram positive and gram negative). By cross linking, it weakens the defenses of the bacteria. On the other hand, ampicillin acts on the enzyme transpeptidase needed for the formation of membrane by bacteria. Hence, both of these drugs have the same effect of preventing the bacteria forming fully functional membrane that is essential for their survival in human body.

Ampicillin has an amino group which is the only difference from amoxicillin in structure. The presence of amino group helps the drug to better penetrate the outer membrane of gram negative bacteria.

Study shows that the absorption of amoxicillin was significantly better compared to ampicillin presenting a higher mean peak serum concentration. Thus, ampicillin has to be administered on empty stomach for better absorption and efficacy.

When come in dosing regimen, ampicillin is take 4 times daily while amoxicillin taken for every 8 hours or higher dose every 12 hours.