Im allergic to penicillin and erythromycine, can i take bactrim (sulfamethoxazole and trimethoprim)?

Yes but for what?: Yes. You can take Bactrim (sulfamethoxazole and trimethoprim) as it is a sulfa drug and different class of drug from penicillin and erythromycin. The real question is for what condition do you want to take? Because the causative organisms for specific diseases may be virus, bacteria, fungus or parasite and the Bactrim (sulfamethoxazole and trimethoprim) is not a magic bullet for all. See your doctorwho would tailor the antibiotic according to organism & sensitivity.

Yes: They are not related. However when a person has reacted to one medication, he is more likely react to a second one even though they are not related.