The FDA recently warned that consumers should not use Baczol Antigripal and Baczol Expectorante containing sulfamethoxazole, trimethoprim, or dipirona. The drugs in question are "labeled in Spanish and marketed as antibiotics for bronchitis, pneumonia, and other respiratory infections". Sulfamethoxazole and trimethoprim can cause serious or even life-threatening conditions such as "liver failure, blood cell abnormalities, and painful skin reactions that can cause skin cells to die and peel off the body in large sheets." Dipirona may cause heart attack and stroke, gastrointestinal bleeding, ulceration, or fatal perforation of the stomach and intestines.
Source: FDA, http://www.fda.gov/Drugs/DrugSafety/ucm365650.htm