Effect of timing of food on absorption of cefpodoxime proxetil

Clinical pharmacokinetics of cefpodoxime: a systematic review

INTRODUCTION

Cefpodoxime, a third-generation cephalosporin, is a broad-spectrum antibiotic widely used to treat acute upper respiratory tract infections (RTI). This systematic review aims to present a comprehensive view of all the available pharmacokinetics (PK) data associated with the pharmacodynamics (PD) parameters of cefpodoxime in humans.

AREAS COVERED

The PubMed, Google Scholar, Cochrane Library, and Science Direct, were systematically searched to identify studies on the PK of cefpodoxime. Out of 746 papers, 26 articles meeting the eligibility criteria were included that have reported the PK data. The drug exposure for the patients undergoing hemodialysis was 50% lower than healthy participants. The renal clearance was almost 27% less in pediatric patients than in adults. The plasma concentrations of cefpodoxime exceeded the minimum inhibitory concentration (MIC) for 90% of skin pathogens, including Streptococcus species and Staphylococcus species (i.e.) < 1 μg/mL and 2-4 μg/mL respectively.

EXPERT OPINION

The current study includes detailed information on clinical PK of cefpodoxime in healthy, diseased, pediatric populations as well as drug-drug interactions and drug-food interactions. Moreover, this systematic review also explicated PK/PD properties of drug with a specific impact on MIC of drug. The present review will also assist clinicians in the development of PK models for cefpodoxime.

Do dietary interventions exert clinically important effects on the bioavailability of β-lactam antibiotics? A systematic review with meta-analyses

BACKGROUND

Managing drug-food interactions may help to achieve the optimal action and safety profile of β-lactam antibiotics.

METHODS

We conducted a systematic review with meta-analyses in adherence to PRISMA guidelines for 32 β-lactams. We included 166 studies assessing the impact of food, beverages, antacids or mineral supplements on the pharmacokinetic (PK) parameters or PK/pharmacodynamic (PK/PD) indices.

RESULTS

Eighteen of 25 β-lactams for which data on food impact were available had clinically important interactions. We observed the highest negative influence of food (AUC or Cmax decreased by >40%) for ampicillin, cefaclor (immediate-release formulations), cefroxadine, cefradine, cloxacillin, oxacillin, penicillin V (liquid formulations and tablets) and sultamicillin, whereas the highest positive influence (AUC or Cmax increased by >45%) for cefditoren pivoxil, cefuroxime and tebipenem pivoxil (extended-release tablets). Significantly lower bioavailability in the presence of antacids or mineral supplements occurred for 4 of 13 analysed β-lactams, with the highest negative impact for cefdinir (with iron salts) and moderate for cefpodoxime proxetil (with antacids). Data on beverage impact were limited to 11 antibiotics. With milk, the extent of absorption was decreased by >40% for cefalexin, cefradine, penicillin G and penicillin V, whereas it was moderately increased for cefuroxime. No significant interaction occurred with cranberry juice for two tested drugs (amoxicillin and cefaclor).

CONCLUSIONS

Factors such as physicochemical features of antibiotics, drug formulation, type of intervention, and patient's health state may influence interactions. Due to the poor actuality and diverse methodology of included studies and unproportionate data availability for individual drugs, we judged the quality of evidence as low.

Effect of time of meal consumption on bioavailability of a single oral 5 mg tacrolimus dose

Tacrolimus (FK506, Prograf) is marketed for the prophylaxis of organ rejection following allogenic liver or kidney transplantation. This study investigated the effect of timing of a standardized breakfast meal on both the rate and extent of tacrolimus absorption following a single 5 mg oral dose. The protocol used a randomized, open-label, four-period, four-treatment, four-sequence crossover design in 16 healthy, nonsmoking, drug-free male subjects between the ages of 22 and 45 years who were within 15% of their ideal body weight. The four treatments were the following: (A) fasting for 10 hours, (B) ingestion 1 hour before breakfast, (C) ingestion immediately following consumption of the breakfast, and (D) ingestion 1.5 hours after beginning consumption of the breakfast. The breakfast, which was consumed over 15 minutes, contained 848 kcal, with 30%, 16%, and 54% of calories derived from fat, protein, and carbohydrate, respectively. Tacrolimus absorption in the fasting state provided the greatest relative bioavailability (p < 0.05 compared with all other three treatments). AUC(0-infinity)) averaged 312, 276, 205, and 203 ng x h/mL for treatments A, B, C and D, respectively. In contradistinction to taking the drug 1 hour prior to a meal, which had a relatively minor impact on the relative extent of absorption (approximately 12%) compared to the fasting state, ingestion of tacrolimus immediately after a meal (treatment C) or 1.5 hours subsequent to a meal (treatment D) had a more pronounced influence. Mean AUC(0-infinity) ratios (fasting to either postmeal treatments) were approximately 1.5, indicating that absorption extent was considerably reduced by ingesting tacrolimus capsules immediately after eating or 1.5 hours thereafter. Absorption was also prolonged following drug ingestion after a meal, as indicated by a mean tmax value in the fasting state of 1.84 hours, relative to 3.41 hours (immediately aftermeal, p = 0.0035) and 3.22 hours (1.5 hours postmeal, p = 0.0094). The only discernable difference in parameters between treatments C and D was with Cmax, with values of 7.19 and 9.04 ng/mL, respectively, but was not statistically significantly different (p = 0.231). Based on these results and those from a prior study, it is recommended that under therapeutic conditions, oral tacrolimus be administered in a consistent manner, both with respect to the type of meal as well as timing of ingestion relative to consumption of the meal.

Cefpodoxime-proxetil hydrolysis and food effects in the intestinal lumen before absorption: in vitro comparison of rabbit and human material

The luminal and mucosal deesterification of the prodrug ester cefpodoxime-proxetil was studied in human duodenal washings in vitro. Enzymatic hydrolysis of the ester, releasing the active third generation cephalosporin, was observed in luminal washing in the same way as it had previously been observed in the rabbit. Eserine and PMSF and HgCl(2) were potent inhibitors of cefpodoxime-proxetil hydrolysis in luminal washing, suggesting the participation of a cholinesterase in the hydrolysis of cefpodoxime-proxetil. These results are in agreement with our previous findings performed in the rabbit. Moreover, cefpodoxime-proxetil directly decreases the acetylcholinesterase activity when tested by a specific enzymatic method. These observations support the hypothesis that the partial oral bioavailability of cefpodoxime-proxetil results from hydrolysis by luminal cholinesterases. In vitro experiments run with rabbit duodenal washing with food components were compared with the pharmacokinetics of cefpodoxime-proxetil in humans. Amino acids, trace elements and vitamins were potent inhibitors for cefpodoxime-proxetil hydrolysis in duodenal washings. Otherwise, lipids (LTC and mixed LCT/MCT) did not interact. In the human, cefpodoxime-proxetil bioavailability is significantly enhanced when tablets are administered with food. The correlation found between animal results and human results in vitro for prospective investigation of a new prodrug ester could be very useful. An in vitro hydrolysis in intestinal animal washings could allow the potentially degraded condition and the food effect of the luminal tract to be assessed before absorption.