Polymyxin antibiotics function by interfering with phospholipid function in bacterial cell membranes. After binding to lipopolysaccharide (LPS) in the outer membrane, polymyxins' hydrophobic tail causes damage to both the inner and outer membranes of Gram-negative bacteria.

Amoxicillin inhibits bacterial cell wall synthesis by interfering with the formation of cross-links between peptidoglycan polymer chains. 

Aminoglycoside antibiotics such as streptomycin and gentamicin have been associated with vestibular toxicity and hearing loss. Aminoglycosides remain in inner ear fluids longer than serum and can have a latent ototoxic effect, causing hearing loss even after the antibiotic has been discontinued. None of the other antibiotics listed are associated with ototoxicity.

Ciprofloxacin belongs to the fluoroquinolone class of antibiotics. Other antibiotics in this class include norfloxacin, levofloxacin, and nadifloxacin.

Rifampin inhibits bacterial RNA synthesis by inhibiting RNA polymerase. This prevents the transcription of proteins within the bacterial cell, leading to cell death.

Hepatotoxicity and potential liver failure are the most serious potential adverse effects of rifampin use. Patients on this medication must establish baseline liver function tests and be monitored for liver damage. None of the other conditions listed are associated with rifampin use.

Aminoglycoside antibiotics are used to treat Gram negative bacteria. They have not been shown to be effective against Gram positive bacteria and are not antifungal. Recall the major difference between the Gram negative and positive bacteria are their cell wall composition; Gram negative have a small proportion of peptidoglycan and a high proportion of lipopolysaccharide, while Gram negative bacteria have a large proportion of peptidoglycan. 

The only aminoglycoside antibiotic among those listed is streptomycin. Other examples of aminoglycosides include tobramycin and gentamicin. All aminoglycosides either end in -mycin or -micin. However, this suffix is not exclusive to aminoglycosides. It is also seen in the macrolides: erythromycin and azithromycin and both macrolides, and in lincosamides such as clindamycin.

Fluoroquinolones (the most commonly prescribed of which is ciprofloxacin) carry a risk of all of the following adverse effects: sudden tendon rupture or tendonitis, hepatotoxicity or liver failure, seizures, and permanent peripheral neuropathy. Other adverse effects include Clostridium difficile associated diarrhea, bone marrow suppression, Steven-Johnson's Syndrome, tremors, and psychosis. The majority of these adverse effects are seen in higher numbers in children and the elderly.

All of the drugs listed frequently cause C. difficile overgrowth and C. difficile associated diarrhea except vancomycin, which is often used as a treatment for persistent C. difficile infections.