I wouldn't trust any OTC dewormer.  Call your vet and tell him you've seen
tape worms.  They should just get you the medication. (as long as the cat
has been seen there in the past year or less)

If the cat is up to date on shots and checkups then call the vet and see if
they will give you something for the tapeworms without an appointment.
Collect some of the segments in case they want to see them to confirm what
it is.

W

Dunno where you are Sherry, so i don't know whether this is relevant, but
here goes anyway:

I tried OTC worm treatments, but they all seemed to have separate tablets
for roundworm and tapeworm. What was worse, i had to weigh the cats and work
out how many of each tablet to give them based on body weight. I ended up
giving each cat up to 4 tablets. That was OK for one, giving her a tablet is
a doddle, but the other one takes a chunk out of your thumb for every tablet
you give her. I tried grinding them up in her food, but she just stopped
eating. Now I get Drontal, see
http://www.stopwormsdead.co.uk/template.php?sectionId=2 from the Vet (it's
prescription only in the UK, maybe OTC in other countries). It's probably a
little more expensive than the OTC versions, but it's easier to administer
and it does work. I can't actually remember how much I pay because I always
get Frontline spot on flea & tick treatment for them at the same time. IIRC,
it costs me less than 10 UKP (18 USD) for 2 cats once every 3 months.

Z

When one of my cats had tape worm I put one of them in a zip-lock bag and
took it in and showed it to the vet tech.  She gave me a pill - I think it
was called dorontal - for about $8.00 and that was the extent of it.

Dee