I don’t have any aminoglycosides and I am aware they can cause renal damage like Fanconi syn. I was not aware that doxycycline was neprhotoxic—are you positive?
Doxycycline is generally nephrotoxic (and hepatotoxic too) only at high doses. In other words, it’s generally not a problem for normal doses in people with normal kidneys and livers
The breakdown products of doxycycline however (i.e. what you get in old doxycycline) are toxic, mainly to the kidneys. The toxicity of expired doxycycline can occur even after taking “normal” doses of the drug and in people with previously healthy kidneys. This toxicity may take the form of Fanconi syndrome.
Is a healthy young person likely to die from taking a few doses of expired doxycycline? Probably not, at least if advanced medical care (an ER and inpatient hospitalization) are available. However, if you think you are saving a few bucks by using expired doxycycline ... you may wish to consider the cost of that ER visit, time in the hospital, and post-hospital follow up. Really, in my opinion, it’s not even a question of being penny wise and pound foolish. It’s more like a question of being penny wise and pound stark raving mad.
And yeah, I’m pretty sure that what I just wrote is true.