There are no over-the-counter meds that actually WORK. You can use them, but they may harm your cat and they will NOT solve the problem. They do not kill the worms - they merely cause the cat to expel some of them - meaning your cat will likely still have worms or just get re-infested.
Prescription meds may seem like they cost more - but in the long run, they cost a LOT less.
The only meds that actually work must be obtained from a vet - or at least with a scrip from a vet.
That sounds very much like round worm, but you need to get a poop sample to a vet. The type of med prescribed will depend upon the type of worm(s).
The meds that are used to kill worms only kill the adult worms. The eggs are still in the cat's system. Those must be allowed to "hatch" and then another dose of meds given to kill the new crop of adult worms. For round worm this cycle is about three weeks. Some vets do it in two.
The meds that the vet will give you depend upon where you are - but will likely either be Drontal, Panacur or StrongidT. I've never heard of anthelban? I'm sure there are other meds though. Anyway... the round worm in this area has become resistant to Drontal. It took us MONTHS to rid our cats of round worm.
While you are treating your cat for worms, scoop as often as possible. If you can afford it, dump and replace the litter weekly. But at the very least bleach the boxes weekly until you get the "all clear" on the poop sample from the vet. After you've done two rounds of the meds, you should take another poop sample in to be sure there are no further signs of worms.