Get a sharps container, take it to the vet when it’s full- I bought ours 4 or 5 years ago (maybe more) and it’s still not full, so doesn’t exactly break the bank! And we use a lot of needles. We also have a plastic bottle bin on farm for bottle disposal, had it a couple of years now and again it’s still not full. Again will take it back to the vet for disposal, or you can call a clinical waste company I guess.
Part used wormers can and should go back to your vet. Empty wormer and pour on bottles go for disposal with our spray cans.