How effective is doxycycline?
What are you trying to treat?So would you say that Amoxicillin is great for lower and upper respiratory infections?
Doxycyline would be best used to treat symptoms of respiratory infection due to disease like Mycoplasma or secondary infection dues to Infectious Bronchitis.
Amoxicillin would be good for wounds, possibly aspiration pneumonia, etc. But it's not an effective drug on disease like Mycoplasma.