Table 3.

Drugs that demonstrated a synergistic antimicrobial action in cooperation with copper (copperaction).

Antibiotic	Mode of Copperaction	Reference
Ditiocarb (Disulfiram)	Copper complex, bypasses the copper homeostatic machinery in Mycobacterium tuberculosis	[161]
8-Hydroxyquinoline	Copper complex and ionophore, thus facilitates the transfer of copper across hydrophobic membranes.	[162]
Thiosemicarbazones	Copper complex and ionophore, target NADPH dehydrogenases	[163]
Phenanthroline	Copper complex with nuclease activity of mainly double-stranded DNA, some interference with respiration and inhibition of RNA polymerase	[164,165,166]
Pyrithione	Copper complex and ionophore, facilitates copper influx	[167]
Tetracycline	Copper complex formation shows an antagonistic effect while complex formation with Cd(II) exhibits a synergistic effect	[168]
Fluoroquinolone	Copper complex formation but with only minor antimicrobial effect, facilitates the transfer of copper across hydrophobic membranes	[169,170]
Aminoglycoside	A weak copper complex formation that is not physiologically relevant, maybe a potential role in DNA damage and formation of reactive oxygen species	[171]