To obtain data on the safety of administering megestrol acetate and dronabinol as single agents or in combination to patients with human immunodeficiency virus (HIV)-wasting syndrome. To obtain preliminary data on the efficacy of single agent and combination therapy with megestrol acetate and dronabinol with regard to weight gain, appetite increase and quality of life in this patient population. To obtain steady-state pharmacokinetics data when megestrol acetate and dronabinol are administered as single agents and in combination.