Barbiturates
Barbiturates/Nutrient Depletion:
BiotinBiotin: Based on human study, phenobarbital may reduce biotin levels through an elevated excretion of certain organic acids (6500847).
CalciumCalcium: In a retrospective study, based on a biochemical survey of people aged 65 and over in a general practice, subjects taking a barbiturate preparation for indications other than epilepsy had a lower serum calcium concentration than did those taking nitrazepam or diazepam due to an altered vitamin D metabolism and hence a reduced serum calcium absorption (323838).
CarnitineCarnitine: Based on human studies, phenobarbital may reduce free and total carnitine levels (9853647, 1941389, 9013816). According to secondary sources, phenobarbital may reduce carnitine levels possibly due to decreased synthesis of carnitine.
DibencozideDibencozide: According to secondary sources, phenobarbital may reduce dibencozide absorption.
Folic acidFolic acid: A report suggests that megaloblastic anemia may have been caused by folic acid deficiency during treatment with barbiturates (601569).
RiboflavinRiboflavin: Based on animal and in vitro research, long-term use of phenobarbital may increase destruction of riboflavin by liver enzymes, increasing the risk of deficiency (1213747, 1205492, 4152603, 4147670).
ThiaminThiamin: Based on secondary sources, barbiturates may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
Vitamin B6/pyridoxineVitamin B6/pyridoxine: According to secondary sources, barbiturates may decrease levels of vitamin B6.
Vitamin B12Vitamin B12: According to secondary sources, barbiturates may decrease levels of vitamin B12.
Vitamin C/ascorbic acidVitamin C/ascorbic acid: Based on secondary sources, the effects of vitamin C may be decreased by barbiturates including phenobarbital (Luminal?, Donnatal?), pentobarbital (Nembutal?), or secobarbital (Seconal?).
Vitamin DVitamin D: In a retrospective study, based on a biochemical survey of people aged 65 and over in a general practice, subjects taking a barbiturate preparation for indications other than epilepsy had a lower serum calcium concentration due to an altered vitamin D metabolism than did those taking nitrazepam or diazepam (323838).
Vitamin EVitamin E: Based on animal study, long-term administration of phenobarbital may reduce vitamin E levels by interfering with vitamin E metabolism (3737267). Based on human study, phenobarbital may reduce serum vitamin E levels and supplementation with vitamin E may be recommended (6213919).
Vitamin KVitamin K: Based on animal study, phenobarbital may reduce vitamin Kand the 2,3-epoxide in the systemic blood concentration through a greater hepatic elimination (6704138). There is conflicting evidence that an extra vitamin K administration may reduce the frequency of symptoms of vitamin K deficiency in pregnant women on a regimen of enzyme-inducing anticonvulsant therapy (8456897, 8456903, 15118607, 16846083, 16812962, 11865131).