To add to unluckiestsoul, the CDC recommends both azythromycin and doxycycline for the treatment of NGU, which includes Chlamydia and other bacterial that cause urethritis. The advantage of zithromax is that you only take 1000mg one time, as opposed to doxycycline, which you take 2x a day for 7 days. NEvertheless, you should not engage in sexual activity for at least 7 days starting from the day you take the medication. They both are effective against chlamydia, and there's some evidence that azythromycin may be more effective against mycoplasma genitalium, which is another bacteria that can cause urethritis.
Btw, you don't say how the chlamydia came into the relationship.
you both should refrain from sex until the coast is clear like a month or so because reinfection is common and can be a real headache. Both medications are effective but take time to start clearing up the infection. Im at work so I dont have to much time to get into detail, but limit drinking and no sex of any kind and take the meds............there both good.