Then you can safely assume you didn't transmit chlamydia or gonorrhea to your husband.
HHH, MD
The zpack was 2 days after my "casual encounter" (big drunken mistake)for treating my strep throat and 1 week BEFORE I had relations with my husband.
worried710 might be right, if you had sex with your husband after your other exposure but before you took azithromycin. Your question doesn't say one way or the other.
HHH, MD
Since you are both having the discharge, and he is having the burning sensation, it's likely that you contracted and transmitted chlamydia or ghonnoreah to him.
An azithromycin Z-pack would treat or prevent chlamydia, most gonorrhea, and most syphilis. Your pink-eye might be viral; a virus called adenovirus type 19 can cause both genital and upper respiratory infection--not usually sexually transmitted. Or you could have acquired an STD not protected by azithromycin, such as herpes. Or the azithromycin might have triggered a yeast infection in you, which is also causing symptoms in your husband. Or he also has other partners and caught another infection (perhaps no surprise, but when one person in a relationship strays, it's often a sign that both persons are at risk of life's temptations....).
Bottom line: I can't distinguish between these possibilities or make any suggestion other than the one you anticipate (and fear): you and your husband need to be seen by a knowledgeable health care provider.
Good luck-- HHH, MD