When can a simple sinus infection become something worse? Took bactrim (sulfamethoxazole and trimethoprim) for 7 days, now excruciating headaches and awful smell in my nose.

Smell concerning. The symptoms you describe are almost always the sign of something serious, especially after just completing a course of antibiotics. Consult an ENT for a thorough evaluation.
Decongestant. It is important to open the nasal passages so that pus cones out. Use a nasal decongestant.
Decongestants . Nasal decongestants can be quite addicting and can make things worse in some cases. See an ENT doc if your symptoms persist for a definitive diagnosis.
Sinus Infection. Sinus infections are not always "simple". Causes can be a combination of bacteria, allergies, viruses, deviated septums, gerd, broken noses, polyps, tumors, foreign bodies, fungal infections, dental abscesses or fractures, hypothyroidism, lupus, sarcoidosis, diabetes and parasites. For more information see our website www.Nwnasalsinus.Com.

Related Questions

I have a sinus infection and just started Bactrim (sulfamethoxazole and trimethoprim) DS yesterday. I've been reading all the negative reviews. Worried about side effects. Is Bactrim (sulfamethoxazole and trimethoprim) ok?

Usually no problem. It indeed can be alarming to read lists of drug side effects. But for Bactrim, (sulfamethoxazole and trimethoprim) most of them are rare and few are permanent or dangerous. The vast majority of people who take it have no probem at all. And your doctor wouldn't have prescribed it unless she believed it would be more helpful than harmful. But recheck with the doctor if you remain concerned. Read more...
Mostly it is fine. Bactrim (sulfamethoxazole and trimethoprim) is a great antibiotic except in some patients it can cause a serious skin rashes associated with Itching. You will likely do fine if there is no rash during the first few days. Good luck. Read more...