that combo is common for mds to give to help with H. pylori. Omeprazole is a proton pump inhibitor used to block/control acid ( i was also on this, for acid reflux) it is not an antibiotic, but doctors will often pair it with an antibiotic for the treatment of h.pylori. the clarithromycin is the antibiotic, so yes you were on an antibiotic along with a acid reducer and the tinidazole is an anti-parasitic drug.