Pill Identification by Imprints: A538 Home Pill Identification by Imprints: A538 2 results GUANFACINE HCL ER 4 MG TABLET Side 1: A538 Color: Blue Side 2: 4 mg Shape: Oblong GUANFACINE HCL ER 4 MG TABLET Side 1: A538 Color: Blue Side 2: 4 mg Shape: Oblong Other Popular Drug Imprint RX 791 M 445 RH37 454 2 55 BI 6 OS 302 MYLAN 2046 M15 247 66 Y NT or EP or E T81 INT AHI 2 BCL 25 UCB 580 UCB 584 RN5 West-ward 202 BP WPI 3385 WATSON 347 B082 ZE 49 PLIVA 482 DISTA 3104 969 MD 562 MO1 FL 290 FL BCM 50 RP103 West-ward 787 81 IP 173 MDV CL64 A/P 12.5 / 30