Bioavailability of gatifloxacin by gastric tube administration with and without concomitant enteral feeding in critically ill patients

Bioavailability of Orally Administered Drugs in Critically Ill Patients

Critically ill patients managed in the Intensive Care Unit (ICU) suffer from several pathophysiological alterations due to critical illness resulting in potential changes in the pharmacokinetics of drugs including systemic absorption. Nevertheless, these patients are still given some medications in unadjusted doses thereby putting the patients at a risk for therapy failure. The objective for this study was to summarize the available evidence regarding oral drug absorption in the ICU. A literature search of the databases MEDLINE, EMBASE, and PubMed was conducted on (February 24, 2020). Articles discussing the rate and/or extent of orally administered drugs in critically ill patients were included. A total of 58 studies were found: 17 interventional studies, 33 observational studies (30 prospective, 3 retrospective) and 8 case reports. A total of 43 articles reported altered drug absorption in critically ill patients suggesting the need for alternative measures to facilitate treatment success. The absorption of orally administered drugs may be altered in critically ill patients. Measures for altered drug absorption in critically ill patients were suggested such as holding tube feeding before and after medication administration, increasing doses of orally administrated drugs and using alternate routes of administration.

Pharmacokinetics of omega-3 fatty acids in patients with severe sepsis compared with healthy volunteers: A prospective cohort study

BACKGROUND

Pharmacokinetics (PK) of pharmaceuticals and pharmaconutrients are poorly understood in critically ill patients, and dosing is often based on healthy subject data. This might be particularly problematic with enteral medications due to metabolic abnormalities and impaired gastrointestinal tract absorption common in critically ill patients. Utilizing enteral fish oil, this study was undertaken to better understand and define PK of enteral omega-3 fatty acids (eicospentaenoic acid [EPA] and docosahexaenoic acid [DHA]) in critically ill patients with severe sepsis.

MATERIALS AND METHODS

Healthy volunteers (n = 15) and mechanically ventilated (MV) adults with severe sepsis (n = 10) were recruited and received 9.75 g EPA and 6.75 g DHA daily in two divided enteral doses of fish oil for 7 days. Volunteers continued their normal diet without other sources of fish oil, and sepsis patients received standard enteral feeding. Blood was collected at frequent intervals during the 14-day study period. Peripheral blood mononuclear cells (PMBCs) and neutrophils were isolated and analyzed for membrane fatty acid (FA) content. Mixed linear models and t-tests were used to analyze changes in FA levels over time and FA levels at individual time points, respectively. PK parameters were obtained based on single compartment models of EPA and DHA kinetics.

RESULTS

Healthy volunteers were 41.1 ± 10.3 years; 67% were women. In patients with severe sepsis (55.6 ± 13.4 years, 50% women), acute physiologic and chronic health evaluation (APACHE) II score was 27.2 ± 8.8 at ICU admission and median MV duration was 10.5 days. Serum EPA and DHA were significantly lower in sepsis vs. healthy subjects over time. PBMC EPA concentrations were generally not different between groups over time, while PBMC DHA was higher in sepsis patients. Neutrophil EPA and DHA concentrations were similar between groups. The half-life of EPA in serum and neutrophils was significantly shorter in sepsis patients, whereas other half-life parameters did not vary significantly between healthy volunteers and sepsis patients.

CONCLUSIONS

While incorporation of n-3 FAs into PBMC and neutrophil membranes was relatively similar between healthy volunteers and sepsis patients receiving identical high doses of fish oil for one week, serum EPA and DHA were significantly lower in sepsis patients. These findings imply that serum concentrations and EPA and DHA may not be the dominant driver of leukocyte membrane incorporation of EPA and DHA. Furthermore, lower serum EPA and DHA concentrations suggest that either these n-3 FAs were being metabolized rapidly in sepsis patients or that absorption of enteral medications and pharmaconutrients, including fish oil, may be impaired in sepsis patients. If enteral absorption is impaired, doses of enteral medications administered to critically ill patients may be suboptimal.

Simo decoction versus domperidone suspension for post-pyloric spiral nasoenteric tube placement: A multicenter, randomized, non-inferiority trial

BACKGROUND & AIMS

Leveraging prokinetics to facilitate trans-pyloric migration is a conventional strategy. However, due to restrictions on the use of domperidone suspension, oral prokinetics is relatively modest. The study aims to assess the effectiveness of simo decoction as an alternative to domperidone suspension in facilitating post-pyloric placement of spiral nasoenteric tubes.

METHODS

A prospective, open-label, parallel, and non-inferiority randomized controlled trial was performed involving critically ill adults in 6 university hospitals in China between September 2017 and May 2019. Patients were randomly assigned to receive either simo decoction 20 ml q8h, or domperidone suspension 20 mg/20 ml q6h for 24 h. The primary outcome was procedure success defined as post-pyloric placement (spiral nasoenteric tubes reached the first portion of the duodenum or beyond confirmed by abdominal X-ray 24 h after tube insertion).

RESULTS

Of 268 patients assessed for eligibility, 224 patients were enrolled and randomly assigned to the simo decoction group or the domperidone suspension group (n = 112 per group). The success rate of post-pyloric placement was 41.1% (46/112) in the simo decoction group, as compared with 47.3% (53/112) in the domperidone suspension group (a risk difference of -6.3%, 95% CI, -19.2% to 6.7%, adjusted risk difference -3.7%, 95% CI -16.3% to 9.0%), in the intention-to-treat analysis, crossing the prespecified margin of -10% for non-inferiority. There were no differences between groups in the success rates of post-D1 (reaching the second portion of the duodenum or beyond), post-D2 (reaching the third portion of the duodenum or beyond), post-D3 (reaching the fourth portion of the duodenum or beyond) and proximal jejunum placement, the incidences of any adverse events, length of ICU stay or mortality in ICU.

CONCLUSIONS

Non-inferiority of simo decoction to domperidone suspension was not confirmed in facilitating post-pyloric placement of spiral nasoenteric tubes. Registration: The trial was registered with the Chinese Clinical Trial Registry at http://www.chictr.org.cn (registration number ChiCTR-INR-17011311).

Drug absorption, distribution, metabolism and excretion considerations in critically ill adults

INTRODUCTION

All critically ill patients require medication to treat organ dysfunction. However, the pharmacokinetics of drugs used to treat these patients is complex due to frequent alterations in drug absorption, distribution, metabolism, and excretion (ADME).

AREAS COVERED

This review examines pharmacokinetic aspects of drug administration for adult intensive care unit (ICU) patients. Specifically, the authors examine the ADME changes that occur and which should be considered by clinicians when delivering drug therapy to critically ill patients.

EXPERT OPINION

Dosage pharmacokinetics determined from single-dose or limited-duration administration studies in healthy volunteers may not apply to critically ill patients. Organ dysfunction among these patients may be due to pre-existing disease or the effects of a systemic or locoregional inflammatory response precipitated by their illness. Alterations in pharmacokinetics observed among the critically ill include altered bioavailability after enteral administration, increased volume of distribution and blood-brain barrier permeability and changes in P-glycoprotein and cytochrome P450 enzyme function. However, the effect of these changes on clinically important outcomes remains uncertain and poorly studied. Future investigations should examine not only pharmacokinetic changes among the critically ill, but also whether recognition of these changes and alterations in drug therapy directed as a consequence of their observation alters patient outcomes.

Drug-nutrient interactions in the intensive care unit: literature review and current recommendations

OBJECTIVE

To describe the interactions between drugs and nutrients and their frequency in the intensive care unit and to assess the professional team's awareness regarding this subject.

METHODS

The keywords "drug interactions" and "nutrition therapy" were searched in the PubMed (specifically MeSH) electronic database. The studies were systematically reviewed for descriptions of the types of interactions between drugs and nutrients, including their frequency and consequences.

RESULTS

Sixty-seven articles were found. Among these, 20 articles were appropriate for the methodology adopted and accomplished the objectives of the study. Of these 20 articles, 14 articles described interactions between drugs and enteral nutrition, three described interactions between drugs and parenteral nutrition, and three described the importance and care required to avoid such interactions.

CONCLUSIONS

The literature about drug and nutrient interactions is limited and suggests the inability of health care teams to recognize the potential for these interactions. Possibly, the elaboration of a protocol to evaluate drug-nutrient interactions will increase the safety and efficacy of therapeutics.

Clinical Equivalency of Ciprofloxacin 750 mg Enterally and 400 mg Intravenously for Patients Receiving Enteral Feeding: Systematic Review

BACKGROUND

Concomitant enteral administration of ciprofloxacin with products containing magnesium, aluminum, and calcium (e.g., as enteral feeds) decreases the oral bioavailability of this antibiotic. The manufacturer currently recommends holding enteral feeds for a total of 8 h after ciprofloxacin is given, but this is not feasible for patients who are receiving continuous enteral feeding. A previous study demonstrated that a higher dose of oral ciprofloxacin (750 mg BID) may compensate for the reduced bioavailability associated with this drug-food interaction, allowing adequate concentrations for effective bactericidal activity.

OBJECTIVE

To evaluate whether ciprofloxacin 750 mg administered enterally is a clinically feasible alternative to ciprofloxacin 400 mg administered intravenously for adults receiving enteral feeds.

METHODS

A literature search was conducted in EMBASE (January 1980 to April 2008) and MEDLINE (January 1949 to April 2008), with no language restrictions, using the key words "ciprofloxacin", "fluoroquinolone", "tube feed", and "enteral". For trials that remained after screening of the abstract, the full text was reviewed and the reference lists were hand-searched to identify additional trials. The following outcomes were prespecified: death, serious adverse events, clinical cure, microbiological cure, re-infection, total adverse events, ratio of area under the curve (AUC, in microgram-hours per millilitre) to minimum inhibitory concentration (MIC, in micrograms per millilitre), ratio of maximum serum concentration (C(max), in micrograms per millilitre) to MIC, and C(max).

RESULTS

The search identified 121 potentially eligible studies, which were screened on the basis of information provided in the abstract. From this initial screening, it was clear that 113 studies did not meet the inclusion criteria. The remaining 8 studies were subjected to a full-text review, which revealed that only 1 study met the inclusion criteria. In that study, ciprofloxacin 750 mg given enterally yielded an AUC similar to that achieved with 400 mg given parentally, but the C(max) was lower. No clinical outcomes were reported.

CONCLUSIONS

There is insufficient evidence from this systematic review to determine whether patients receiving enteral feeds concomitantly with enteral ciprofloxacin 750 mg BID will achieve clinical outcomes similar to those receiving parenteral ciprofloxacin 400 mg BID.

Parenteral to oral conversion of fluoroquinolones: low-hanging fruit for antimicrobial stewardship programs?

OBJECTIVE

To estimate avoidable intravenous (IV) fluoroquinolone use in Veterans Affairs (VA) hospitals.

DESIGN

A retrospective analysis of bar code medication administration (BCMA) data.

SETTING

Acute care wards of 128 VA hospitals throughout the United States.

METHODS

Data were analyzed for all medications administered on acute care wards between January 1, 2006, and December 31, 2010. Patient-days receiving therapy were expressed as fluoroquinolone-days (FD) and divided into intravenous (IV; all doses administered intravenously) and oral (PO; at least one dose administered per os) FD. We assumed IV fluoroquinolone use to be potentially avoidable on a given IV FD when there was at least 1 other medication administered via the enteral route.

RESULTS

Over the entire study period, 884,740 IV and 830,572 PO FD were administered. Overall, avoidable IV fluoroquinolone use accounted for 46.8% of all FD and 90.9% of IV FD. Excluding the first 2 days of all IV fluoroquinolone courses and limiting the analysis to the non-ICU setting yielded more conservative estimates of avoidable IV use: 20.9% of all FD and 45.9% of IV FD. Avoidable IV use was more common for levofloxacin and more frequent in the ICU setting. There was a moderate correlation between avoidable IV FD and total systemic antibiotic use (r = 0.32).

CONCLUSIONS

Unnecessary IV fluoroquinolone use seems to be common in the VA system, but important variations exist between facilities. Antibiotic stewardship programs could focus on this patient safety issue as a "low-hanging fruit" to increase awareness of appropriate antibiotic use.

Pharmacokinetic drug interactions of antimicrobial drugs: a systematic review on oxazolidinones, rifamycines, macrolides, fluoroquinolones, and Beta-lactams

Like any other drug, antimicrobial drugs are prone to pharmacokinetic drug interactions. These drug interactions are a major concern in clinical practice as they may have an effect on efficacy and toxicity. This article provides an overview of all published pharmacokinetic studies on drug interactions of the commonly prescribed antimicrobial drugs oxazolidinones, rifamycines, macrolides, fluoroquinolones, and beta-lactams, focusing on systematic research. We describe drug-food and drug-drug interaction studies in humans, affecting antimicrobial drugs as well as concomitantly administered drugs. Since knowledge about mechanisms is of paramount importance for adequate management of drug interactions, the most plausible underlying mechanism of the drug interaction is provided when available. This overview can be used in daily practice to support the management of pharmacokinetic drug interactions of antimicrobial drugs.

Comparison of the enteral and intravenous lansoprazole pharmacodynamic responses in critically ill patients

BACKGROUND

While proton pump inhibitors are frequently administered in the intensive care unit, the pharmacodynamic response of acid suppression between the enteral and intravenous (IV) route is unknown.

AIM

To compare the pharmacodynamic response between enteral and IV lansoprazole in intensive care unit patients requiring stress ulcer prophylaxis therapy.

METHODS

Adult mechanically ventilated patients were randomized to receive 72 h of daily enteral [lansoprazole oral disintegrating tablet (LODT) 30 mg mixed in 10 mL of water via a nasal gastric tube] or IV lansoprazole (30 mg over 30 min) therapy. Serial blood samples were collected after the first and third dose and analysed for pharmacokinetic parameters. Pharmacodynamic determination of intragastric pHmetry began prior to the first dose and continued for 72 h using a single channel pH microelectrode.

RESULTS

Nineteen intensive care unit patients were randomized [LODT (n = 10); IV-L (n = 9)]. LODT bioavailability was 76%. LODT maintained gastric pH > 4 longer than IV-L at both 24 h (7.4 vs. 5.9 h; P = 0.039) and 72 h (10.4 and 8.9 h; P = 0.046) and resulted in a greater average pH over the first 24 h (3.67 vs. 2.89; P = 0.03).

CONCLUSION

Despite a lower bioavailability, enteral lansoprazole suppresses acid in intensive care unit patients to a greater extent than IV lansoprazole.

Selected pharmacokinetic issues in patients with chronic kidney disease

Pharmacotherapy plays an important role in the care of a chronic kidney disease (CKD) patient but delivering this therapy can be challenging. Besides alterations in the pharmacokinetic parameters of absorption, distribution, metabolism and elimination, the average CKD patient must take multiple medications each day. The likelihood of an adverse drug reaction increases with each medication added to these patients' daily regimen. In this article we discuss selected pharmacokinetic issues unique to CKD patients.

Estudio de la actividad comparada de varias fluoroquinolonas frente a Pseudomonas aeruginosa mediante la determinación de la concentración preventiva de mutantes

INTRODUCTION

The objective of this study was to compare the activity of ciprofloxacin, levofloxacin, moxifloxacin, gatifloxacin and ofloxacin against Pseudomonas aeruginosa by determining the mutant prevention concentration (MPC).

METHODS

Thirty-four clinical isolates of Pseudomonas aeruginosa causing nosocomial infection were studied. MPC values were determined using an inoculum of 10(10) cfu/mL on Mueller-Hinton plates with serial dilutions of the antibiotics. The microorganisms were classified according to whether the patients had been previously treated with fluoroquinolones or not.

RESULTS

The fluoroquinolone with the lowest MPC values was ciprofloxacin, followed by levofloxacin. Analysis of strains from patients previously treated with fluoroquinolones showed persistent susceptibility according to the CLSI criteria, but with lower activity of all the drugs.

CONCLUSIONS

Although the microorganism remained susceptible to fluoroquinolones according to classical methods, the suitability of using these drugs in patients with severe infection and a history of fluoroquinolone use should be evaluated.

Approaches to treatment of community-acquired pneumonia in the emergency department and the appropriate role of fluoroquinolones

The Emergency Department is a critical point of care for patients presenting with signs and symptoms of community-acquired pneumonia (CAP). The initial diagnosis, the decision to admit or discharge, the timing of initiating treatment, and appropriateness of the empirical therapy are key factors in successful management. Rising resistance rates to commonly used CAP antibiotics has complicated empirical treatment. Respiratory fluoroquinolones represent an important therapeutic option for patients with co-morbidities and risk factors for penicillin-, macrolide-, and multi-drug-resistant S. pneumoniae infections. Ensuring appropriate use is required to maintain their high level of effectiveness in key respiratory pathogens. Treatment guidelines from the Infectious Diseases Society of America, American Thoracic Society, and Centers for Disease Control and Prevention are available to assist emergency physicians in developing clinical pathways to ensure appropriate use of available therapies.

Effect of Ensure on the Oral Bioavailability of Gatifloxacin in Healthy Volunteers

STUDY OBJECTIVE

To determine the effect of Ensure on the relative oral bioavailability of gatifloxacin in healthy volunteers.

DESIGN

Single-dose, randomized, crossover study.

SETTING

University-affiliated research center.

SUBJECTS

Twelve healthy volunteers (six men, six women) aged 18 years or older with no clinically significant abnormal findings on physical examination or in medical history. Intervention. Subjects consumed 120 ml of study liquid-water or Ensure-every 30 minutes for five doses. With the second dose, subjects ingested a single gatifloxacin 400-mg tablet that had been uniformly crushed and mixed into the study liquid.

MEASUREMENTS AND MAIN RESULTS

Serial blood samples were collected for 48 hours, and gatifloxacin concentrations were determined by high-performance liquid chromatography. Pharmacokinetic data were analyzed by using noncompartmental methods. Maximum serum concentration (Cmax) and area under the serum concentration-time curve from zero to infinity (AUC0-infinity) were tested for bioequivalence after log-transformation of the data. Comparison of parameters for gatifloxacin administered with water versus those with Ensure showed that Cmax (4.35 +/- 0.90 vs 2.41 +/- 0.58 mug/ml, p<0.0001) and AUC(0-infinity) (42.4 +/- 10.1 vs 31.3 +/- 8.3 mg*hr/L, p<0.0001) were significantly decreased with Ensure, and bioequivalence was not achieved for either parameter. The geometric least squares mean ratio was 0.553 (90% confidence interval [CI] 0.501-0.611) for Cmax and 0.730 (90% CI 0.664-0.802) for AUC0-infinity. The median time to reach Cmax was significantly prolonged when gatifloxacin was administered with Ensure versus that with water (2.5 hrs vs 1.0 hr, p=0.006).

CONCLUSIONS

The Cmax and AUC0-infinity of gatifloxacin were significantly decreased when the drug was administered with Ensure. The clinical significance of these findings will depend on the offending pathogen and its susceptibility to gatifloxacin.