Moxifloxacin is a synthetic fluoroquinolone antibiotic agent. Bayer AG developed the drug (initially called BAY 12-8039) and it is marketed worldwide (as the hydrochloride) under the brand name Avelox (in some countries also Avalox) for oral treatment. Each tablet contains 400 mg. In most countries the drug is also available in parenteral form for intravenous infusion. Moxifloxacin is also sold in an ophthalmic solution (eye drops) under the name Vigamox for the treatment of conjunctivitis.

Moxifloxacin can be used to treat respiratory infections, including acute sinusitis, acute exacerbations of chronic bronchitis, and community-acquired pneumonia, as well as skin and skin structure infections. Moxifloxacin is also used for the treatment of complicated intra-abdominal infections, such as those seen in hospitals. Because moxifloxacin is primarily metabolized and eliminated via the hepatic route, it is not indicated for the treatment of urinary tract infections.

Moxifloxacin inhibits bacterial topoisomerase II (DNA gyrase) and topoisomerase IV. Topoisomerases are essential enzymes which play a crucial role in the replication and repair of bacterial DNA. This mechanism is lethal to susceptible bacteria. Moxifloxacin is often referred to as a chemotherapeutic drug because its mode of action has so far not been noted in any naturally occurring or semi-synthetic antibiotic

Clarithromycin is a macrolide antibiotic used to treat pharyngitis, tonsillitis, acute maxillary sinusitis, acute bacterial exacerbation of chronic bronchitis, pneumonia (especially atypical pneumonias associated with Chlamydia pneumoniae or TWAR), skin and skin structure infections, and, in HIV and AIDS patients to prevent, and to treat, disseminated Mycobacterium avium complex (MAC). In addition, it is sometimes used to treat Legionellosis. Clarithromycin is available under several brand names, for example Biaxin, Klaricid, Klabax, Claripen, Claridar and Clacid.