The odor and discharge that you describe sounds most consistent with bacterial vaginosis; it's not a result of your partner's medications. This infection is not serious or particularly worrisome, but the symptoms are certainly a major annoyance!
You could first try RepHresh, a product that may alleviate the symptoms by correcting the vaginal pH (you can read more about pH in this recent blog post). Vaginosis can also be treated with an antibiotic, administered orally or vaginally.
Douching is not helpful and can be harmful: It disrupts normal bacteria in the vagina and makes you more susceptible to infection.