Hi, My Mom Is Taking Oxetol 300 Mg L(as She

Hi, my mom is taking oxetol 300 mg l(as she gets fits) from 15 years(not sure exactly, may be more than that). She is in USA and will be leaving to India tomorrow 29thapril. She just realized that she lost one strip of tablets. She will reach India day on May 1st. So, does missing of oxetol 300 mg dose for 3 days cause any problem? We are not able to find this medicine anywhere near our place in USA. What should we do? I'm worried if it will be a problem during their travel.