Appetite Stimulants

Anabolic Steroids - For example, Winstrol. May help with regaining muscle. Slight appetite enhancement.

Cyproheptadine (Periactin)
http://www.peteducation.com:80/article.cfm?cls=0&cat=1454&articleid=1394

The vet may recommend 1/4 of a 4mg tablet or even, like in our case, 1/2 of a 4mg tablet, but in many cats this is WAY TOO MUCH. Try 1/8 of a 4mg tablet to start off with. Signs of too much is: pacing, hyper, agitated, howling, vomiting, weakness in the back legs, confusion, and falling. Better to start off slow.
CAUTION: Possible adverse interaction with calcium blockers.

Catnip

Raw Liver - Yuk, but cats seem to like it! Cut in small squares about 1/2 inch or smaller in size. Don't cut long strips... don't want to choke on it.

Reglan
http://www.peteducation.com:80/article.cfm?cls=0&cat=1459&articleid=1441

Valium (Diazepan)
http://www.peteducation.com/article.cfm?cls=0&cat=1458&articleid=1396

5 mg. tablet. dose: less than 1/4 once or twice a week. The effects last for several days. (Possible negative effects, weakness, wobbliness, liver toxicity)

Valium is not recommended for long term use.