DO NOT GIVE PEPCID W/O VET'S APPROVAL!
Never give Pepcid to a cat without first knowing what is wrong with the cat. That is really bad advice to tell someone to give 1/4 Pepcid because their cat is vomiting. First of all, there are several reasons why a cat could be vomiting and Pepcid only addresses one reason - excess stomach acid production. If that is the reason, you need to get to the root of the problem, not just suppress symptoms. Second of all, 1/4 of a Pepcid tab is an indefinite dose. Pepcid AC comes in two different doses - 10 mg and 20 mg. There is also Pepcid Complete and chewable Pepcid which contain ingredients which may be contraindicated for Ipo. So which Pepcid are we talking about? And how often are you supposed to give this medication to a cat? This drug is cleared through the kidneys and could cause kidney damage.
It is a good idea to have bloodwork done to check the status of metabolic functions (e.g. kidneys, liver, pancreas).