 Follow-up Period- All subjects will return to the investigational site for this visit, regardless of whether they have treated a qualifying TTH with study medication. Subjects who have not treated a qualifying TTH with study drug during the Treatment Period will be asked to return study materials and undergo safety evaluations at the End-of-Study Visit and will be discharged from the study. Subjects who have treated a qualifying TTH with study drug during the Treatment Period will ingest a 140 mg dose of open-label TNX-201 at this visit and undergo urine and blood sample collection for 3 hours post-dose to characterize each subjects genetic metabolism and PK profile. 