Texas Health and Safety Code - HEALTH & SAFETY § 481.068. Confidentiality

(a) The director may authorize a person engaged in research on the use and effects of a controlled substance to withhold the names and other identifying characteristics of individuals who are the subjects of the research. A person who obtains the authorization may not be compelled in a civil, criminal, administrative, legislative, or other proceeding to identify the individuals who are the subjects of the research for which the authorization is obtained.

(b) Except as provided by Sections 481.074 and 481.075, a practitioner engaged in authorized medical practice or research may not be required to furnish the name or identity of a patient or research subject to the department, the Department of State Health Services, or any other agency, public official, or law enforcement officer. A practitioner may not be compelled in a state or local civil, criminal, administrative, legislative, or other proceeding to furnish the name or identity of an individual that the practitioner is obligated to keep confidential.

(c) The director may not provide to a federal, state, or local law enforcement agency the name or identity of a patient or research subject whose identity could not be obtained under Subsection (b).