Pharmacokinetic interactions of cefprozil with food, propantheline, metoclopramide, and probenecid in healthy volunteers

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.

Development and Validation of an HPLC-MS/MS Method for Rapid Simultaneous Determination of Cefprozil Diastereomers in Human Plasma

Background

Both cis- and trans-cefprozil have antimicrobial activity, but their potencies are quite different. It is therefore necessary to develop a sensitive method to simultaneously determine both isomers for pharmacokinetic and bioequivalence studies.

Methods

An LC-MS/MS method, using stable isotope-labeled cefprozil as the internal standard, was developed and validated. The analytes were extracted from plasma by protein precipitation and separated on a reverse-phase C₁₈ column using a gradient program consisting of 0.5% formic acid and acetonitrile within 4 min. The mass spectrometry acquisition was performed with multiple reaction monitoring in positive ion mode using the respective [M+H]⁺ ions, m/z 391.2→114.0 for cefprozil and 395.0→114.5 for cefprozil-D4.

Results

The calibration curves were linear over the ranges of 0.025–15 μg/mL for cis-cefprozil and 0.014–1.67 μg/mL for trans-cefprozil. The accuracies for the cis and trans isomers of cefprozil were 93.1% and 103.0%, respectively. The intra- and interassay precisions for the QC samples of the isomers were < 14.3%. The intra- and interassay precisions at the LLOQ were < 16.5%.

Conclusions

The method was sensitive and reproducible and was applied in a pilot pharmacokinetic study of healthy volunteers.

Pharmacokinetics of an oral drug (acetaminophen) administered at various times relative to subcutaneous injection of pramlintide in subjects with type 2 diabetes

Pramlintide, an adjunct treatment to mealtime insulin for patients with type 2 and type 1 diabetes, aids glycemic control by suppressing postprandial glucagon secretion, slowing gastric emptying, and enhancing satiety. Because gastric emptying affects oral medication absorption, this placebo-controlled, single-blind, crossover study examined the absorption of 1000 mg of acetaminophen elixir administered -2, -1, 0, +1, and +2 hours relative to pramlintide (120 microg) or 0 hours relative to placebo in 24 patients with type 2 diabetes. When acetaminophen administration occurred 0, +1, or +2 hours relative to pramlintide, the maximum observed plasma concentration of acetaminophen decreased 14% to 29%, and time to maximum observed plasma concentration increased by 0.8 to 1.2 hours compared with administration 0 hours relative to placebo. Pramlintide treatment slowed but did not alter the extent of acetaminophen absorption (area under the concentration-time curve). No serious adverse events or withdrawals were reported. Oral agents should be administered at least 1 hour before or 2 hours after pramlintide injection if rapid onset of action is required for efficacy.

Effect of altered gastric emptying and gastrointestinal motility on metformin absorption

AIMS

The purpose of this in vivo human study was to assess the effect of altered gastric emptying and gastrointestinal motility on the absorption of metformin in healthy subjects.

METHODS

An open-label, three treatment, three period crossover study was conducted in 11 healthy volunteers. Each subject received 550 mg metformin hydrochloride in solution alone; 5 min after a 10 mg i.v. dose of metoclopramide; and 30 min after a 30 mg oral dose of propantheline. Metformin solution was radiolabeled by the addition of 99mTc-DTPA. The gastrointestinal transit of the solution was monitored by gamma scintigraphy and the pharmacokinetic data were correlated with the scintigraphic findings.

RESULTS

Scintigraphic data indicated that pretreatment with metoclopramide decreased gastric emptying time and increased gastrointestinal motility while pretreatment with propantheline had the opposite effect. The systemic disposition of metformin was not altered by pretreatment with metoclopramide and propantheline, as judged by unchanged renal clearance and elimination half-life of metformin. Extent of metformin absorption was essentially unchanged after pretreatment with metoclopramide. However, AUC(0,infinity) and % UR (percent dose excreted unchanged in urine) generally increased with increase in gastric emptying time and small intestinal transit times. GI overlay plots showed that the absorption phase of metformin plasma profile always coincided with gastric emptying and the beginning of decline of metformin plasma concentrations was usually associated with the colon arrival. Only in cases where the intestinal transit was drastically prolonged by propantheline pretreatment, was a decline in plasma levels observed prior to colon arrival.

CONCLUSIONS

Metformin is primarily absorbed from the small intestine. The extent of metformin absorption is improved when the gastrointestinal motility is slowed. These findings have significant implications in the design of a metformin modified release dosage form.

Effect of metoclopramide and loperamide on the pharmacokinetics of didanosine in HIV seropositive asymptomatic male and female patients

The pharmacokinetics of orally-administered didanosine were evaluated in 6 male and 6 female HIV seropositive patients to determine the effect of pretreatment with metoclopramide, an inducer of gastrointestinal motility, and loperamide, which retards motility. Using a randomized, balanced, crossover design, each patient received the following three treatments under fasting conditions: didanosine as a single agent, didanosine 5 min after a single 10 mg intravenous dose of metoclopramide, and didanosine 1 h after the final of 4 doses, 4 mg each, of loperamide. Serial blood and urine samples were collected for up to 12 h after each dose. Plasma and urine aliquots were analysed for intact didanosine using HPLC with UV detection. Pharmacokinetic parameter values were calculated using noncompartmental methods. The mean Cmax values were significantly greater for the didanosine single agent (2.04 micrograms.ml-1) and didanosine with metoclopramide (2.30 micrograms.ml-1) treatments than for the combination of didanosine with loperamide (1.57 microgram.ml-1). The t1/2 in males was significantly greater than in females for the didanosine (1.75 vs 1.12 h, respectively) and didanosine with metoclopramide treatments (1.74 vs 1.20 h, respectively). No significant treatment or gender effects were observed for AUC or UR (urinary recovery). The pharmacokinetics of didanosine were not altered appreciably by dosing with metoclopramide. Administration with loperamide affected the rate but not the extent of absorption. There were no clinically relevant differences between males and females in the disposition of didanosine.

Review of in vitro activity, pharmacokinetic characteristics, safety, and clinical efficacy of cefprozil, a new oral cephalosporin

OBJECTIVE

To review the pharmacokinetics, microbiology, clinical efficacy, safety, and tolerance of cefprozil, a new, broad-spectrum oral cephalosporin.

DATA SOURCES

Published clinical trials and microbiologic, pharmacokinetic, and safety data were identified by MEDLINE; additional references were derived from bibliographies of these articles; microbiologic data on file were provided by Bristol-Myers Squibb.

STUDY SELECTION

Only published comparative clinical trial reports are included in the review of clinical efficacy. Noncomparative clinical data pertaining to uses of cefprozil not approved by the Food and Drug Administration are not included.

DATA SYNTHESIS

Data are presented on the in vitro microbiologic activity of cefprozil against 10,152 bacterial isolates, including most of the clinically important streptococci (e.g., Streptococcus pyogenes, Streptococcus pneumoniae), beta-lactamase-positive and -negative Staphylococcus aureus and Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Proteus mirabilis, Clostridium difficile, and numerous other gram-negative aerobes and anaerobes. In clinical trials, cefprozil appears to be at least as effective as commonly used comparison agents such as cefaclor, cefixime, and amoxicillin/clavulanic acid. Additionally, cefprozil is better tolerated than the latter two agents, especially with regard to gastrointestinal adverse effects.

CONCLUSIONS

Cefprozil is a broad-spectrum cephalosporin that provides coverage against both gram-negative and -positive bacteria that may cause otitis media, pharyngitis/tonsillitis, skin and skin-structure infections, secondary bacterial infection of acute bronchitis, and acute bacterial exacerbations of chronic bronchitis. The beta-lactamase stability of cefprozil appears to exceed that of other oral cephalosporins for some important pathogens. Cefprozil is used primarily for second-line treatment as less-expensive, first-line generic alternatives generally are available. Cefprozil demonstrates clinical advantages over many other orally administered beta-lactam antibiotics in terms of antimicrobial spectrum, a once- or twice-daily dosing regimen, and/or reduced incidence of adverse effects.