Drug-induced malabsorption of vitamin B 12 . V. Intestinal pH and absorption of vitamin B 12 during treatment with para-aminosalicylic acid

Right Atrial Deformation Using Cardiovascular Magnetic Resonance Myocardial Feature Tracking Compared with Two-Dimensional Speckle Tracking Echocardiography in Healthy Volunteers

Speckle tracking echocardiography (STE), and more recently, cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) provides insight into all phases of atrial function. The aim of our study was to compare all phases of RA strain using CMR-FT and STE and also assess the relationship between RA and LA strain. A total of 61 healthy volunteers with mean age of 45 ± 13 years had adequate tracking for analysis on CMR-FT and 2D-STE. Females had larger RA reservoir strain (39 ± 15% vs. 32 ± 13%, p = 0.046) and conduit strain (26 ± 12% vs. 20 ± 9%, p = 0.03) when compared to males, but was not the case with booster strain (14 ± 7% vs. 12 ± 6%, p = 0.45). In comparison with STE derived strain, the RA reservoir and conduit strain were not significantly different between CMR-FT and the three echocardiography gating methods (p > 0.05 for all). Noticeably, there were no significant differences in strain and strain rate between RA and LA function using CMR-FT (p > 0.05 for all). RA strain and strain rate using CMR-FT had fair and good intra- and inter-observer reproducibility and had superior reproducibility compared to STE derived strain.

The Relevance of Vitamin and Iron Deficiency in Patients with Inflammatory Bowel Diseases in Patients of the Swiss IBD Cohort

BACKGROUND ANDAIMS

Vitamin and iron deficiencies are common in patients with inflammatory bowel disease (IBD) as a result of chronic intestinal inflammation, increase in demand, or dietary restrictions. Here, we assessed the frequency of complications in relation to deficiency of iron, folate acid, and vitamin B12 in patients enrolled in the nationwide Swiss Inflammatory Bowel Disease Cohort Study (SIBDCS).

METHODS

A total of 2666 patients were included in the study, 1558 with Crohn's disease (CD) and 1108 with ulcerative colitis (UC).

RESULTS

Iron deficiency anemia was detected in 19.6% of CD patients and 21.6% of UC patients. In CD patients low BMI and nonsmoker status were positively associated with anemia. In both CD and UC, malabsorption syndrome, defined as failure of the GI tract to absorb 1 or more substances from the diet, was found to be significantly associated with anemia (6.2% and 3.8%, respectively) and current steroid use (40% CD, 52.7% UC). In CD patients with ileal (31.7% vs 20%) and colonic (29.9% vs 25%) disease location folate deficiency was significantly higher than in patients with ileocolonic CD or upper GI involvement. In CD patients, vitamin B12 deficiency was associated with the onset of stenosis and intestinal surgery (42.9% vs 32.8% and 46% vs 33% for patients with versus without B12 deficiency).

CONCLUSION

Our data indicate that due to frequent occurrence of deficiency states, regular monitoring and substitution of vitamins and iron are mandatory and may prevent long-term intestinal and extraintestinal complications in IBD patients.

Interactions affecting drug absorption

The influence of drug-drug and drug-food interactions affecting the absorption of orally administered medication is reviewed. Drug-drug interactions can be classified in terms of indirect effects by one drug on gastrointestinal tract physiology influencing the absorption of other drugs, or direct interactions involving altered pH, adsorption, absorption, or chelation. Most, but not all, drug-drug interactions result in reduced or delayed systemic drug availability. Drug-food interactions may result in reduced, delayed, or increased systemic drug availability. The absorption of only a small number of drugs is unaffected by concomitant food intake. The degree of interaction and whether it positively or negatively affects drug absorption depends on a number of factors including the physical and chemical nature of the drug, the formulation, the type of meal, and the time interval between eating and dosing. Mechanisms of drug-food interactions are not well characterised. They clearly involve both direct and indirect factors in a similar fashion to drug-drug interactions, but indirect factors probably predominate. Reduced or delayed drug absorption is generally attributed, at least in part, to delayed stomach-emptying due to food. Increased absorption may also result from delayed stomach-emptying facilitating greater drug dissolution before it passes from the stomach into the small intestine. Increased bioavailability of some drugs, e.g. propranolol, metoprolol and labetalol, may be related to reduced presystemic clearance. The potential clinical implications of drug-drug and drug-food interactions must be taken into account with oral medications in order to minimise variations in systemic drug availability and hence in clinical efficacy.