Ex vivo 12 h bactericidal activity of oral co-amoxiclav (1.125 g) against beta-lactamase-producing Haemophilus influenzae

Does adjuvant antibiotic treatment after drainage of anorectal abscess prevent development of anal fistulas? A randomized, placebo-controlled, double-blind, multicenter study

BACKGROUND

The risk of fistula formation is a major concern after incision and drainage of an anorectal abscess.

OBJECTIVE

Our objective was to the test the effects of antibiotic treatment on fistula formation after incision and drainage of anorectal abscesses.

DESIGN

Randomized, placebo-controlled, double-blind study.

SETTING

Multicenter trial at 3 teaching hospitals in Turkey.

PATIENTS

Patients who underwent abscess drainage between September 2005 and January 2008 were evaluated for eligibility. Exclusion criteria included penicillin allergy, antimicrobial agent usage before enrolment, other infection, previous anorectal surgery, inflammatory bowel disease, suspicion of Fournier gangrene, secondary and recurrent anorectal abscesses, anal fistula at time of the surgery, immune compromised states, and pregnancy.

INTERVENTION

Patients were randomly assigned to receive placebo or amoxicillin-clavulanic acid combination treatment for 10 days after abscess drainage.

MAIN OUTCOME MEASURES

The primary end point was rate of anorectal fistula formation at 1-year follow-up.

RESULTS

: Of 334 patients assessed for eligibility, 183 entered the study (placebo, 92; antibiotics, 91). Data were available for per-protocol analysis from 151 patients (placebo, 76; antibiotics, 75) with a mean age of 37.6 years; 118 patients (78.1%) were men. Overall, 45 patients (29.8%) developed anal fistulas during 1-year follow-up. Fistula formation occurred in 17 patients (22.4%) in the placebo group and in 28 patients (37.3%) in the antibiotic group (P = .044). Risk of fistula formation was increased in patients with ischiorectal abscess (odds ratio, 7.82) or intersphincteric abscess (odds ratio, 3.35) compared with perianal abscess.

CONCLUSION

Antibiotic treatment following the drainage of an anorectal abscess has no protective effect regarding risk of fistula formation.

A physiological model to evaluate drug kinetics in patients with hemorrhagic shock followed by fluid resuscitation. Application to amoxicillin-clavulanate

PURPOSE

To build a physiologically based pharmacokinetic model describing drug kinetics in interstitial fluid in case of hemorrhagic shock, and to propose a simple method to determine the subset of influential parameters that may be estimated with the data at hand.

METHODS

The model, which accounts for alterations of regional blood flows and body water distribution, was fitted to amoxicillin and clavulanate kinetic data, assessed in 12 trauma patients with hemorrhagic shock by comparison with 12 healthy volunteers. The predictions were the free concentrations of amoxicillin and clavulanate in 14 organs.

RESULTS

In all tissues of trauma patients, the rate of distribution was lower, but the steady-state level was higher than those in healthy participants. Blood volume was reduced by 25% and blood flow in organs other than lung, brain, and heart were reduced by 18%. Compared with healthy subjects, the time that free amoxicillin concentration remained above 8 mg/L in the interstitial fluid of trauma patients was higher in blood and muscles, and lower in the tendon compartment.

CONCLUSIONS

The results and predictions were consistent with the knowledge in this field. The model may be useful to optimize clinical trial designs and drug dosing regimens.

A new amoxicillin/clavulanate therapeutic system: Preparation, in vitro and pharmacokinetic evaluation

A new peroral amoxicillin/clavulanate therapeutic system composed of immediate release tablet and controlled release floating capsule was developed and evaluated by in vivo bioavailability study. Pharmacokinetic (PK) parameters for amoxicillin and clavulanic acid of the new therapeutic systems: AUCt, AUCi, (AUCt/AUCi), Cmax, Tmax, kel, T(1/2) and additionally for amoxicillin T(4) and T(2) were calculated from the plasma levels. The study confirmed enhanced pharmacokinetic parameters of a newly developed therapeutic system containing 1500 mg of amoxicillin and 125 mg of clavulanic acid. Prolonged time over MIC of amoxicillin in relation to a regular immediate release amoxicillin/clavulanate formulation was confirmed.

Prevention of Surgical Site Infection After Open Prosthetic Inguinal Hernia Repair: Efficacy of Parenteral Versus Oral Prophylaxis with Amoxicillin-Clavulanic Acid in a Randomized Clinical Trial

The aim of this prospective study was to compare the efficacy of oral versus parenteral prophylactic amoxicillin-clavulanic acid for preventing surgical site infection after open prosthetic mesh repair of inguinal hernia. A total of 480 inguinal-hernia patients were randomly assigned to two groups. Group I (n = 240) received 1.313 g oral amoxicillin-clavulanic acid 2 hours before operation, and group II (n = 240) received 1.2 g of the same drug combination intravenously approximately 30 minutes before surgery. Patients were examined four times during 1 year of follow-up (at 7-10 days, 4-6 weeks, 6 months, and 12 months postoperation), and data related to surgical site infections were collected. Seventy-two patients were excluded due to confounding factors during and after the operation. There were no statistically significant differences between group I (final n = 208) and group II (final n = 200) with respect to age, sex distribution, body mass index, American Anesthesiology Association grade, frequencies of different hernia types, duration of surgery, and the experience levels of the principal surgeon in the operations. One of the 208 (0.5%) patients in group I and 3 of the 200 (1.5%) patients in group II developed superficial surgical site infections (p > 0.05). None of the infections required mesh removal. There were no deep surgical site infections in either group, and there was one case of hernia recurrence in each group. For patients undergoing open prosthetic repair of inguinal hernia, oral amoxicillin-clavulanic acid is safe, significantly less costly, and equally effective in preventing surgical site infection as the same dose given parenterally.