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 SG 326 L922 Poly 782 T 57 MYLAN 6900 M 060 PD 155 A112 STARLIX e5 112 M A11 RP 701 H 94 M 547 T1 75 OV YB U 137 547 Andrx 700 PAR 822 801 54 758 A02 logo and 012 R150 O 180 or O 215 or O 250 or O-M ER 4 MP 116 INS C371 FL11 ATN 100 ZC 65 GG 624 311 KC 10 OV 111 barr 323 SB 4142