Which bug are you trying to kill?
I'm going after Giardia. If this fails I will try albendazole+metronidazole for 10 days again and repeat after 15 days. I will also be using Biotics Research - ADP oregano oil. Some people were successful with this oregano when treating protozoa (one was cured and another was cured with a mix of meds & oregano but not taken at the same time).