There's no such thing as oral Frontline, and as far as I know, no oral meds that will do ticks. He was probably given Capstar, which only kills fleas for 24 hours. It's cheap and doesn't need a prescription, so lots of shelters use it to control fleas.

You can try Adams, not sure how well it will do on ticks. Avoid Hartz, it's one of the most useless things out there. Most OTC products are not very effective, but you can always try.