if the regular pills are'nt working, it might be safer in the long run
taking your cat to the vet.

just my 2 cents,
ghost

I don't know about this meds,but I would take a stool sample to the vet and
have them give you pills for the worms. I do not trust over the counter
wormers.
Gail

Botanist, not vet, here.  Praziquantel is available in the US
(Drontal and Droncit are the two I'm most familiar with) -- I'm not sure if
it's available as a topical.  How do you know that the current meds (which
were what?) were ineffective?

Long ago, I did a stint in a human parasitology lab... it was pretty common
to find multiple species infesting an individual, and we had to nail them
all to "cure things up"; my suggestion, given the information here, is
that you want to talk to a vet anyhow... some worms are really difficult to
find in a stool specimen, but can sure cause trouble.  Then there are all
the other fun things like Giardia, or Clostridium difficile, that come
along for the ride.  IMHO, it's better to know what you're really dealing
with when a parasiticide seems to fail.

I am in the UK and walk past a pet shop every evening, they have it there,
if you use PayPal, I can send you some.

Cheers
FD

I bet you are talking about tape worms. Over the counter stuff dos not
usually work on them. A vet has to give them something for that. Same as for
hook worms.
Gina