Strep antibiotics. Another medication - are you taking one right now? The antibiotic of choice for strep throat is Penicillin VK (most potent and cheapest) and its derivatives. If allergic to it, other choices are the Erythromycin group, Cipro (ciprofloxacin) group, cephalosporin group. The last group should be taken with caution as there could be an associated cross-allergy in 10% of people.