Treatment failures secondary to drug interactions with divalent cations and fluoroquinolone

Effects of Magnesium, Calcium, and Aluminum Chelation on Fluoroquinolone Absorption Rate and Bioavailability: A Computational Study

Fluoroquinolones (FQs) are a widespread class of broad-spectrum antibiotics prescribed as a first line of defense, and, in some cases, as the only treatment against bacterial infection. However, when administered orally, reduced absorption and bioavailability can occur due to chelation in the gastrointestinal tract (GIT) with multivalent metal cations acquired from diet, coadministered compounds (sucralfate, didanosine), or drug formulation. Predicting the extent to which this interaction reduces in vivo antibiotic absorption and systemic exposure remains desirable yet challenging. In this study, we focus on quinolone interactions with magnesium, calcium and aluminum as found in dietary supplements, antacids (Maalox) orally administered therapies (sucralfate, didanosine). The effect of FQ-metal complexation on absorption rate was investigated through a combined molecular and pharmacokinetic (PK) modeling study. Quantum mechanical calculations elucidated FQ-metal binding energies, which were leveraged to predict the magnitude of reduced bioavailability via a quantitative structure-property relationship (QSPR). This work will help inform clinical FQ formulation design, alert to possible dietary effects, and shed light on drug-drug interactions resulting from coadministration at an earlier stage in the drug development pipeline.

Drug-related problems among older patients: Analysis of 8 years of pharmacist's interventions

OBJECTIVES

To analyse the most frequent DRP over time and pharmacists' interventions made among older patients aged over 75 years old. DRP between older patients and younger patients aged 18 to 74 years and between older patients treated in geriatric wards or not were also compared.

METHODS

A cross-sectional observational study conducted on DRP detected by pharmacists at the university hospital centre of Lyon and prospectively recorded in the Act-IP© database from January 2008 to December 2015.

RESULTS

A total of 56,223 DRP were investigated - 19,056 in older patients and 37,167 in younger patients. A supratherapeutic dosage was mainly reported (22.4% in older patients vs. 19.0% in younger patient) and pharmacists made interventions mostly to adjust dosage (27.3% vs. 24.2%). Physicians' acceptance was significantly lower in older patients (57.1% vs. 64.3%). DRP associated to a drug included a supratherapeutic use of acetaminophen (5.2% vs. 3.8%) and hypnotics (4.0% vs. 1.4%), medication in cardiology used without indication (1.4% vs. 0.2%) and underuse of vitamin D (1.2% vs. 0.1%). Supratherapeutic dosages were more significantly detected with a lower overall physicians' acceptance in older patients treated in general wards.

CONCLUSIONS

This study highlights the specificity of DRP among older patients and encourages health care professionals to remain especially alert regarding older patients treated in general wards. These findings can contribute to define or adjust training needs and quality indicators to improve the daily practices of health care professionals.

Revisiting Oral Fluoroquinolone and Multivalent Cation Drug-Drug Interactions: Are They Still Relevant?

Fluoroquinolones are a widely-prescribed, broad-spectrum class of antibiotics with several oral formulations notable for their high bioavailability. For certain infections, fluoroquinolones are the first line or only treatment choice. When administered orally, fluoroquinolones require proper administration to ensure adequate systemic absorption and, thereby, protect patients from treatment failure. Oral drug preparations that contain multivalent cations are well known to chelate with fluoroquinolones in the gastrointestinal tract; co-administration may lead to clinically significant decreases in oral fluoroquinolone bioavailability and an overall increase in fluoroquinolone-resistant bacteria. Based on a search and evaluation of the literature, this focused review describes oral fluoroquinolone-multivalent cation drug-drug interactions and their magnitude and offers several clinical management strategies for these potentially clinically significant interactions.

Oral Fluoroquinolone Administration and Interacting Substances: The Pediatric Diet Dilemma

Concomitant administration of enteral fluoroquinolones (FQs) with divalent or trivalent cation-containing compounds results in a reduction in FQ bioavailability. A review of enteral FQ administration with regards to the timing of divalent or trivalent cation-containing compounds in pediatric patients revealed a high number of inappropriately administered FQs. Suggestions for reducing the number of inappropriately timed FQ administrations are presented here.

Deep learning improves prediction of drug-drug and drug-food interactions

Drug interactions, including drug-drug interactions (DDIs) and drug-food constituent interactions (DFIs), can trigger unexpected pharmacological effects, including adverse drug events (ADEs), with causal mechanisms often unknown. Several computational methods have been developed to better understand drug interactions, especially for DDIs. However, these methods do not provide sufficient details beyond the chance of DDI occurrence, or require detailed drug information often unavailable for DDI prediction. Here, we report development of a computational framework DeepDDI that uses names of drug-drug or drug-food constituent pairs and their structural information as inputs to accurately generate 86 important DDI types as outputs of human-readable sentences. DeepDDI uses deep neural network with its optimized prediction performance and predicts 86 DDI types with a mean accuracy of 92.4% using the DrugBank gold standard DDI dataset covering 192,284 DDIs contributed by 191,878 drug pairs. DeepDDI is used to suggest potential causal mechanisms for the reported ADEs of 9,284 drug pairs, and also predict alternative drug candidates for 62,707 drug pairs having negative health effects. Furthermore, DeepDDI is applied to 3,288,157 drug-food constituent pairs (2,159 approved drugs and 1,523 well-characterized food constituents) to predict DFIs. The effects of 256 food constituents on pharmacological effects of interacting drugs and bioactivities of 149 food constituents are predicted. These results suggest that DeepDDI can provide important information on drug prescription and even dietary suggestions while taking certain drugs and also guidelines during drug development.

Impact of Educational Interventions to Prevent Drug Interactions between Oral Fluoroquinolone or Tetracycline Antibiotics with Polyvalent-Cation Supplements

Purpose

Fluoroquinolone and tetracycline antibiotics are routinely used for the treatment of a variety of bacterial infections. A disadvantage with their oral administration is the potential for a drug interaction leading to decreased absorption when coadministered with oral supplements containing polyvalent cations. The objective of this study was to evaluate the impact of several inservices aimed at educating nursing staff on reducing this drug interaction.

Methods

To assess the impact of the educational interventions, a retrospective chart review was conducted in two phases to determine the incidence of the drug interaction. Phase 1 was conducted before implementation of the educational inservices. Following the educational inservices, phase 2 was conducted to determine their impact on reducing coadministration.

Results

This interaction occurs frequently in hospitals; we found that these antibiotics were given within 2 hours of polyvalent-cation containing supplements in 72.5% of patients before inservices. An inservice involving multiple approaches significantly reduced the frequency of the drug interaction to 10%; P < 0.001.

Conclusion

Educational inservices directed toward nursing staff were successful in significantly reducing the incidence of this drug interaction.

Prescriptions analysis by clinical pharmacists in the post-operative period: a 4-year prospective study

BACKGROUND

Clinical pharmacists can help prevent medication errors. However, data are scarce on their role in preventing medication prescription errors in the post-operative period, a high-risk period, as at least two prescribers can intervene, the surgeon and the anesthetist. We aimed to describe and quantify clinical pharmacist' intervention (PIs) during validation of drug prescriptions on a computerized physician order entry system in a post-surgical and post-transplantation ward. We illustrate these interventions, focusing on one clearly identified recurrent problem.

METHODS

In a prospective study lasting 4 years, we recorded drug-related problems (DRPs) detected by pharmacists and whether the physician accepted the PI when prescription modification was suggested.

RESULTS

Among 7005 orders, 1975 DRPs were detected. The frequency of PIs remained constant throughout the study period, with 921 PIs (47%) accepted, 383 (19%) refused and 671 (34%) not assessable. The most frequent DRP concerned improper administration mode (26%), drug interactions (21%) and overdosage (20%). These resulted in a change in the method of administration (25%), dose adjustment (24%) and drug discontinuation (23%) with 307 drugs being concerned by at least one PI. Paracetamol was involved in 26% of overdosage PIs. Erythromycin as prokinetic agent, presented a recurrent risk of potentially severe drug-drug interactions especially with other QT interval-prolonging drugs. Following an educational seminar targeting this problem, the rate of acceptation of PI concerning this DRP increased.

CONCLUSION

Pharmacists detected many prescription errors that may have clinical implications and could be the basis for educational measures.