Panacur is usually the one used, and deemed to be one of the safest - though tbh I`d be very wary about giving out general ratios where it or others wormers are concerned, if for no other reason than every species is different, as is every individual. Your best bet, bar taking them/it to the vets so they can judge in person, would be to simply ring them up, and ask for the vet to prepare you a solution for X lizard, at X age and weight...though may want to know though if you have any proof (lab test report etc) that they actually have worms, as giving them blindly can do more harm than good (upset their natural flora) - though they usually don`t have a problem preparing one for you, for a few pounds, and you`ll have piece of mind that it`s been done professionally
worming can knock their appetite, probly best to get fecal so you know if and what type of worms there are, so you can get the right wormer, some are only available through a vet....different ones kill different things.
also use a probiotic in the drinking water at the same time.
* edited to add * also panacur comes in two different strenghts, so working out how much to use needs careful maths work.