Obesity surgery is acknowledged as a highly effective therapy for morbidly obese patients.
Beneficial short-term effects on common comorbidities are practically undisputed.
However, a growing data pool from long-term follow-up reveals increasing evidence of potentially severe nutritional and pharmacological consequences.
Dr Stein and colleagues from Germany assessed the prevalence, causes and symptoms of complications after obesity surgery, and compared therapy recommendations for macro- and micronutrient deficiencies.
The team explored surgically-induced effects on drug absorption and bioavailability, discussing ramifications for long-term therapy and prophylaxis.
|Complications are associated with pre-operative and/or post-operative malnutrition |
|Alimentary Pharmacology & Therapeutics|
PubMed, Embase and MEDLINE were searched using terms including, but not limited to, bariatric surgery, gastric bypass, obesity surgery and Roux-en-Y, coupled with secondary search terms, e.g. anaemia, micronutrients, vitamin deficiency, bacterial overgrowth, drug absorption, pharmacokinetics, undernutrition.
All studies in English, French or German published 1980 through 2014 were included.
The team observed that macro- and micronutrient deficiencies are common after obesity surgery.
The research team noted that the most critical, depending on surgical technique, are hypoalbuminemia, and deficiencies of vitamins B1, B12 and D, iron and zinc.
Many drugs commonly administered to obese patients are subject to post-operative and/or PPI-associated changes affecting bioavailability and absorption.
Dr Stein's team commented, "Complications are associated with pre-operative and/or post-operative malnutrition or procedure-related changes in intake, absorption and drug bioavailability."
"The high prevalence of nutrient deficiencies after obesity surgery makes life-long nutritional monitoring and supplementation essential."
"Post-operative changes to drug absorption and bioavailability in bariatric patients cast doubt on the validity of standard drug dosage and administration recommendations."