22. Sexually active females of childbearing potential not using reliable contraception for at least 1 month prior to study start and not agreeing to use such methods during the entire study period and for at least 1 month thereafter *Reliable contraceptive methods are defined as intrauterine devices (IUDs), combination type contraceptive pills, hormonal implants, double barrier method, injectable contraceptives and surgical procedures (tubal ligation or vasectomy).