What other drugs affect Thiamin (thiamine), vitamin B1?
Reduced levels of thiamin in blood and cerebrospinal fluid have been reported in individuals taking phenytoin (Dilantin®) for extended periods of time. Antacids may lower thiamin levels in the body by decreasing absorption and increasing excretion or metabolism. Barbiturates may lower thiamin levels in the body by decreasing absorption and increasing excretion or metabolism. Loop diuretics, particularly furosemide (Lasix®), have been associated with decreased thiamin levels in the body by increasing urinary excretion (and possibly by decreasing absorption and increasing metabolism). Examples of other loop diuretics include bumetanide (Bumex®), ethacrynic acid (Edecrine®), and torsemide (Demadex®). Theoretically, this effect may also occur with other types of diuretics, including thiazide diuretics such as chlorothiazide (Diuril®), chlorthalidone (Hygroton®, Thalidone®), hydrochlorothiazide (HCTZ, Esidrix®, HydroDIURIL®, Ortec®, Microzide®), indapamide (Lozol®), and metolazone (Zaroxoly
