- For women of childbearing potential, must have used effective contraceptive methods for previous 4 weeks and agree to continue using such methods during the study and for at least 4 months after completing the study, this must include the use of a male/female latex barrier method of contraception (for male participants (See APPENDIX K). TMTB is a pregnancy category D drug. A female of childbearing potential is defined as a female who has not been in natural menopause for the previous, consecutive 24 months, or undergone hysterectomy or bilateral oophortectomy. Women of childbearing potential must have a negative serum pregnancy test within 24 hours before the initiation of TMTB therapy.