Really.....this could be a possible emergency situation, and you are writing to a forum? Instead of waiting for a response from us, you need to take action immediately before that drug gets into your cat's body. CALL THE EMERGENCY VET NOW!!!! Don't even take a chance.
Since you have a computer, you could do a quick research of HCG and also on how to induce vomiting.
Wow, I don't know, but call your Vet right away and ask them. If your Vet is closed, call your nearest Animal ER. How is kitty acting?