Question: how long does it take for doxycycline to work on bronchitis?
Answer: “Took 100mg once per day for 6 days with 200mg on the first day and it has resulted in a major improvement but having to go back to the doctors as although improved my chest is still not clear. No side effects for me at all.” “Took after 8 days of doxycycline for an unrelenting chest cough.