Three Part Question
In [thiamine deficient patients without Wernickes encephalopathy] is [parental delivery of thiamine better than the oral route] at[achieving bioavailability without side effects]?
A 56 year old male attends the emergency department with cellulitis in his left leg. He is unkempt and drinks heavily. The cellulitis can be treated as an out patient with oral antibiotics, but you suspect he is thiamine deficient as a result of chronic alcohol abuse. You are therefore about to prescibe an intravenous infusion of thiamine as you have always given it this way. This will comit you to an inpatient admission and beds are at a premium.You wonder whether there is any basis for your prescribing practice - perhaps oral thiamine would be just as effective.
Medline 1966-03/04 using the Ovid interface.
[(exp thiamine OR thiamine.af OR (vitamin adj5 b1).af) AND (exp infusions, intravenous/ OR exp injections, intravenous OR intravenous.af OR exp infusions, parenteral OR parenteral.af) AND (exp administration, oral OR oral.af OR exp tablets OR tablet.af OR po.af)] LIMIT to human AND English Language.
Altogether 25 papers found of which 2 were relevant to the three part question
|Author, date and country
||Study type (level of evidence)
|Tallaksen CME et al,|
|6 healthy volunteers
IV v oral bolus 50mg doses||Crossover study||Mean total increase in blood thiamine diphosphate||IV mean 55.5 (sd 23.0)%|
oral 1.8x baseline
Inconsistencies in calculations as shown
Statistical significance not assessed
Reporting appears biased|
|Baines M et al,|
|25 healthy alcoholics
250 mg thiamine daily IM vs oral||Controlled trial||Thiamin diphosphate levels at 1 day||Increase in both groups. Only statistically significant in IM group|
|Thiamin diphosphate levels at 5 days||Statistically significant and identicalincrease in both groups|
Clearly concordance with treatment also has to be considered. This has not been considered at all in the papers found.
Clinical Bottom Line
Oral thiamine administration is as effective as parenteral administration after 5 days. In compliant alcoholics without encephalopathy oral administration is the route of choice.
- Tallaksen CME, Sande A, Bohmer T, et al. Kinetics of thiamin and thiamin esters in human blood, plasma and urine after 50mg intravenously or orally. Eur J Clin Pharmacol 1993;44:73-78.
- Baines M, Bligh JG, Madden JS Tissue thiamin levels of hospitalised alcoholics before and after oral or parenteral vitamins. Alcohol Alcohol 1988;(23)1:49-82.