My mother spoke at the meeting preceding the FDA [1] requiring a black-box warning be added to that class of antibiotics. Rupturing tendons is bad, but it gets a lot worse than that.
She suffered life-altering symptoms which ended her career of 25 years in insurance sales.
The drug is routinely prescribed and dispensed without patients being warned of these symptoms. Just a few months ago, she was at a pharmacy and overheard the drug being dispensed and asked the pharmacist why she didn’t warn the person who received it about the possible reactions.
It apparently takes too much time to tell them, according to that pharmacist.
[1]: https://www.fda.gov/drugs/drug-safety-and-availability/fda-d...