Johnny Lee Richards (Richards), Texas prisoner # 493244, appeals the dismissal of his civil rights action filed under 42 U.S.C. § 1983 for failure to state a claim upon which relief can be granted. Richards contends that drugs are being placed in his food without his consent. He further contends that he is being denied access to the courts because he is not being provided with law books and legal supplies. He also asserts that his mail is being intercepted and he is being denied adequate medical care. He contends that the defendants have failed to investigate these allegations.

On appeal, Richards does not identify any error in the district court’s determination that he failed to state a claim against the defendants in their supervisory roles. His assertions in his brief are conclusory and inadequately briefed. Although pro se briefs are liberally construed, even pro se litigants must brief arguments to preserve them. Yohey v. Collins, 985 F.2d 222, 224-25 (5th Cir. 1993). “A party who inadequately briefs an issue is considered to have abandoned the claim.” Green v. State Bar of Texas, 27 F.3d 1083, 1089 (5th Cir. 1994). Consequently, the claims against the defendants are deemed abandoned.

The district court did not err in finding that Richards failed to state a claim against the Bill Clements Law Library and Mailroom. Richards has alleged no fact showing that he has been prejudiced in his ability to prepare and transmit a necessary legal document to a court. See Lewis v. Casey, 518 U.S. 343, 351, 116 S.Ct. 2174, 135 L.Ed.2d 606 (1996). Additionally, he fails to assert a cognizable claim regarding his mail being intercepted. See Brewer v. Wilkinson, 3 F.3d 816, 825 (5th Cir. 1993). Additionally, Richards’s allegation that the Bill Clements High Security Administration is placing drugs in his food is vague and conclusory. As such, his allegation is insufficient to establish a 42 U.S.C. § 1983 claim. See Arnaud v. Odom, 870 F.2d 304, 307 (5th Cir. 1989).

Lastly, the district court did not err in finding that Richards failed to state a claim against the Bill Clements Medical Department. Richards does not specifically identify anyone who has denied him medical care, nor does he allege facts that would show anyone has wantonly disregarded an excessive risk to his health. See Farmer v. Brennan, 511 U.S. 825, 847, 114 S.Ct. 1970, 128 L.Ed.2d 811 (1994).

Based on the foregoing, the judgment of the district court is AFFIRMED. Richards’s motions for a preliminary injunction and attorney’s fees are DENIED.