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 U 400 VP 044 T 50 LANNETT G231 259 or 310 logo and 5710 724 MP 442 HP 512 TUMS 3 logo and LANNETT T 543 T1 75 M C1 VASO 20 5126 V M377 RG 11 I1 7188 logo and 4405 Lilly 3232 CL 57 NXT 1044 W W C 1 T20 T 194 CP 25 IP 253 CN 1 PARLODEL 2 1/2 44 585 300 ER 14/10 L052 GG 621 RX 505