Carrots are rich in carotenes, which are substances related to vitamin A. They're found in the orange pigments and are good for you, but, if you eat lots and lots of carrots, you can develop a yellowish or orange cast to your skin. It's mostly noticeable on the soles of your feet and the palms of your hands.
Benadryl is another decongestant safe for use in cats, although it is usually not as effective as chlortrimeton in treating congestion. Benadryl is generally more beneficial with treating snake bites, reactions to vaccinations, itching, and insect bites.
Acepromazine is a prescription tranquilizer use by veterinarians in dogs and cats. Acepromazine is typically used prior to anesthesia and surgery because of its sedative effects and because it can prevent vomiting. It is also used as an aid in controlling excited animals during examination, treatment, and grooming.