Expired tetracyclines or tetracyclines allowed to stand at a pH less than 2 are reported to be nephrotoxic due to the formation of a degradation product, anhydro-4-epitetracycline causing Fanconi syndrome. In the case of<unk> , the absence of a hydroxyl group in C-6 prevents the formation of the nephrotoxic compound. Nevertheless, tetracyclines and<unk>  itself have to be taken with caution in patients with kidney injury, as they can worsen azotemia due to catabolic effects. Chemical properties<unk> ,<unk>  monohydrate and<unk>  hyclate are yellow, crystalline powders with a bitter taste. The latter smells faintly of ethanol; a 1% aqueous solution has a pH of 2–3; and the specific rotation is −110° cm³/dm·g in 0.01 N methanolic hydrochloric acid. + Solubility Solubility in<unk> <unk>  monohydrate<unk>  Hyclate Water very slightly very slightly freely Ethanol very slightly very slightly sparingly Aqueous acids freely freely Alkali hydroxyde solutions freely freely Chloroform very slightly practically insoluble practically insoluble Diethyl ether insoluble practically insoluble practically insoluble
Doxycycline
Oxytetracycline
Amikacin
Streptomycin
Eravacycline
Minocycline
Secnidazole
Sarecycline