Sunitinib inhibits postoperative adhesions in a rabbit model

Pharmacokinetic drug-drug interaction between erlotinib and paracetamol: A potential risk for clinical practice

BACKGROUND

Erlotinib is a tyrosine kinase inhibitor available for the treatment of non-small cell lung cancer. Paracetamol is an analgesic agent, commonly used in cancer patients. Because these drugs are often co-administered, there is an increasing issue of interaction between them.

OBJECTIVE

The aim of the study was to investigate the effect of paracetamol on the pharmacokinetic parameters of erlotinib, as well as the influence of erlotinib on the pharmacokinetics of paracetamol.

METHODS

The rabbits were divided into three groups: the rabbits receiving erlotinib (I_ER), the group receiving paracetamol (II_PR), and the rabbits receiving erlotinib+paracetamol (III_ER+PR). A single dose of erlotinib was administered orally (25mg) and was administered intravenously (35mg/kg). Plasma concentrations of erlotinib, its metabolite (OSI420), paracetamol and its metabolites - glucuronide and sulphate were measured with the validated method.

RESULTS

During paracetamol co-administration we observed increased erlotinib maximum concentration (C_max) and area under the plasma concentration-time curve from time zero to infinity (AUC_0-∞) by 87.7% and 31.1%, respectively. In turn, erlotinib lead to decreased paracetamol AUC_0-∞ by 35.5% and C_max by 18.9%. The mean values of paracetamol glucuronide/paracetamol ratios for C_max were 32.2% higher, whereas paracetamol sulphate/paracetamol ratios for C_max and AUC_0-∞ were 37.1% and 57.1% lower in the II_PR group, when compared to the III_ER+PR group.

CONCLUSIONS

Paracetamol had significant effect on the enhanced plasma exposure of erlotinib. Additionally, erlotinib contributed to the lower concentrations of paracetamol. Decreased glucuronidation and increased sulphation of paracetamol after co-administration of erlotinib were also observed.

Hemostatic sponge effect on adhesion prevention in a porcine model

BACKGROUND

In this work, we aimed to assess the preventive effect of an absorbable hemostatic collagen sponge (HCS) on the reduction of postsurgical gynecological adhesions in a porcine model.

MATERIALS AND METHODS

Forty female pigs were subjected to a right uterine horn myotomy and left uterine horn deserosation. They were randomly divided into two groups, HCS application and control, which were rearranged into laparotomy and laparoscopy groups. Resulting adhesions were macroscopically and microscopically semiquantitatively analyzed after a 5 mo follow-up.

RESULTS

The incidence of adhesion-free animals did not significantly differ between groups, although it increased when the HCS was placed in both laparotomy (from 10%-12.5%) and laparoscopy groups (from 20%-50%). On the contrary, a significant reduction was observed in adhesion severity when the HCS was applied in the laparotomy groups (P < 0.01). Regarding microscopic study, hemostatic sponge application significantly reduced the inflammation score in the laparoscopic approach (P < 0.01). Fibrosis, unlike inflammation, differs between both approaches. In the laparoscopic group, fibrosis was reduced with application of the HCS, whereas in the laparotomy group greater fibrosis was observed within the HCS group.

CONCLUSIONS

HCS has shown to be safe for gynecological use. Although number and extent of adhesions did not decrease with HCS, inflammation and adhesions' severity were reduced in the laparoscopic and laparotomy approaches, respectively.

The effect of sunitinib on the plasma exposure of intravenous paracetamol and its major metabolite: paracetamol glucuronide

The study aimed to examine the effect of sunitinib on the plasma exposure of intravenous paracetamol and its major metabolite, paracetamol glucuronide. Both drugs share metabolic pathways in the liver, and the drug interactions between sunitinib and paracetamol administered in higher doses were reported. These interactions resulted in hepatotoxicity. The adult New Zealand male rabbits were divided into three groups (6 animals each): rabbits receiving sunitinib and paracetamol (SUN + PC), rabbits receiving sunitinib (SUN), and a control group receiving paracetamol (PC). Sunitinib was administered orally (25 mg) and paracetamol was administrated intravenously (35 mg/kg). Blood samples for sunitinib and SU12662 assays were collected up to 96 h after drug administration and for paracetamol and paracetamol glucuronide up to 300 min after drug administration. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin were analysed before and after drug administration. A number of pharmacokinetic parameters were analysed. There were no differences in the levels of AST, ALT, and bilirubin among the groups at either time point. Significantly higher values of AUC_0–t, AUC_0–∞, and C_max and lower clearance and volume of distribution of paracetamol were observed in group PC vs. group SUN + PC (p < 0.01). The maximum plasma concentration of paracetamol glucuronide tended to be higher in group PC 213.27 μg/mL (90 % CI 1.06, 1.25; p = 0.0267). Statistically significant differences were revealed for paracetamol glucuronide mean residence time (MRT); MRT was higher in group SUN + PC than in group PC (p = 0.0375). The mean t_max of paracetamol glucuronide was similar in both groups: SUN + PC and group PC (15 and 20 min, respectively). The mean t_max of sunitinib was different in groups SUN + PC and SUN (10.0 and 7.0, respectively; p = 0.0134). At the studied doses, neither of the drugs, whether administered alone or together, had hepatotoxic effects. The present study was not able to confirm that sunitinib, administered at low doses in conjunction with paracetamol, displays a hepatoprotective effect. Significant differences were observed in some pharmacokinetic parameters of paracetamol.

A novel adenosine precursor 2',3'-cyclic adenosine monophosphate inhibits formation of post-surgical adhesions

BACKGROUND

Intraperitoneal adenosine reduces abdominal adhesions. However, because of the ultra-short half-life and low solubility of adenosine, optimal efficacy requires multiple dosing.

AIM

Here, we compared the ability of potential adenosine prodrugs to inhibit post-surgical abdominal adhesions after a single intraperitoneal dose.

METHODS

Abdominal adhesions were induced in mice using an electric toothbrush to damage the cecum. Also, 20 μL of 95 % ethanol was applied to the cecum to cause chemically induced injury. After injury, mice received intraperitoneally either saline (n = 18) or near-solubility limit of adenosine (23 mmol/L; n = 12); 5'-adenosine monophosphate (75 mmol/L; n = 11); 3'-adenosine monophosphate (75 mmol/L; n = 12); 2'-adenosine monophosphate (75 mmol/L; n = 12); 3',5'-cyclic adenosine monophosphate (75 mmol/L; n = 19); or 2',3'-cyclic adenosine monophosphate (75 mmol/L; n = 20). After 2 weeks, adhesion formation was scored by an observer blinded to the treatments. In a second study, intraperitoneal adenosine levels were measured using tandem mass spectrometry for 3 h after instillation of 2',3'-cyclic adenosine monophosphate (75 mmol/L) into the abdomen.

RESULTS

The order of efficacy for attenuating adhesion formation was: 2',3'-cyclic adenosine monophosphate > 3',5'-cyclic adenosine monophosphate ≈ adenosine > 5'-adenosine monophosphate ≈ 3'-adenosine monophosphate ≈ 2'-adenosine monophosphate. The groups were compared using a one-factor analysis of variance, and the overall p value for differences between groups was p < 0.000001. Intraperitoneal administration of 2',3'-cAMP yielded pharmacologically relevant levels of adenosine in the abdominal cavity for >3 h.

CONCLUSION

Administration of 2',3'-cyclic adenosine monophosphate into the surgical field is a unique, convenient and effective method of preventing post-surgical adhesions by acting as an adenosine prodrug.

Mechanism for reduced pericardial adhesion formation in hypercholesterolemic swine supplemented with alcohol

OBJECTIVE

Previous experiments in Yorkshire swine demonstrated significantly fewer pericardial adhesions and intramyocardial collagen deposition at reoperative sternotomy in animals supplemented with vodka but not with red wine. The purpose of this experiment was to determine a mechanism for adhesion reduction.

METHODS

Twenty-seven male Yorkshire swine were fed a high-cholesterol diet to simulate conditions of coronary artery disease followed by the surgical placement of an ameroid constrictor to the left circumflex coronary artery to induce chronic ischaemia. Postoperatively, control pigs continued their high-fat/cholesterol diet alone, whereas the two experimental groups had diets supplemented with either red wine or vodka for 7 weeks followed by reoperative sternotomy and cardiac harvest.

RESULTS

The expression of related adhesion focal tyrosine kinase (RAFTK) and caspase 3 in the sodium dodecyl sulphate (SDS)-soluble myocardial fraction was significantly higher only in the vodka-supplemented group. In the more soluble fraction, the expression of caspase 3, cleaved caspase 3 and caspase 9 was lower in both the vodka and red wine treatment groups.

CONCLUSIONS

In the SDS-soluble lysate fraction, likely representing the transmembrane/cell-extracellular matrix (ECM), a significant increase in RAFTK and caspase 3 expression was seen only in the vodka-treated animals, which may explain why this group demonstrated significantly fewer pericardial adhesions. Caspase expression/signalling was not increased in the more soluble myocardial lysate, suggesting that the increased apoptotic signalling was specific to the epicardial-ECM.

Sunitinib reduces recurrent pelvic adhesions in a rabbit model

BACKGROUND

Adhesions represent a major problem after abdominal and pelvic procedures. The purpose of the present study was to determine the effect of sunitinib (Sutent, SU11248), a Food and Drug Administration-approved receptor tyrosine kinase inhibitor, on recurrent pelvic adhesion formation after pelvic adhesiolysis in a rabbit model.

MATERIALS AND METHODS

A total of 20 New Zealand white rabbits underwent a uterine abrasion procedure, followed by an adhesiolysis procedure 4 weeks later. Before adhesiolysis, the rabbits were randomized to sunitinib at 10 mg/kg/d or placebo. These were administered as 1 dose preoperatively followed by 10 doses postoperatively. The rabbits were killed 30 d after the adhesiolysis procedure. At death, the adhesions were scored, and a total adhesion score (presented as the median and interquartile range [IQR]) was calculated according to the percentage of uterine involvement and the tenacity of the adhesions.

RESULTS

All the rabbits survived the operative procedures without complications. The sunitinib-treated rabbits (n = 10) had a significantly lower uterine involvement score (median 2.0, IQR 1.0-3.0) than the placebo-treated rabbits (median 4.0, IQR 3.0-4.0; P = 0.02). The sunitinib-treated rabbits also had median tenacity score of 3.0 (IQR 3.0-4.0) compared with a median of 4.0 (IQR 4.0-4.0; P = 0.04) in the placebo-treated rabbits (n = 10). The median total score in the sunitinib-treated rabbits was 5.0 (IQR 4.0-6.25) compared with 8.0 (IQR 6.75, 8.0) in the placebo-treated rabbits (P = 0.01).

CONCLUSIONS

Sunitinib treatment might be an efficacious strategy to reduce recurrent adhesion formation after pelvic procedures.

In vivo evaluation of in situ polysaccharide based hydrogel for prevention of postoperative adhesion

In this paper, the carboxymethyl chitosan/oxidized dextran hydrogel was developed and its potency application in the prevention of postoperative adhesion was investigated. The developed hydrogel showed porous and interconnected interior structure with pore size about 250 μm, which was sensitive to lysozymic solution (1.5 μg/ml) with almost complete degradation after 4 weeks of in vitro incubation. In vivo study suggested that the developed hydrogel showed the great capacity on the prevention of postoperative adhesions in rat model. According to the result of histopathological examination, it clearly showed that the mesothelial cell layer of abdominal wall and cecum were completely recovered after 7 days of surgery in 3% carboxymethyl chitosan/oxidized dextran hydrogel group, while obvious adhesion between abdominal wall and cecum was observed as treatment with saline solution or 3% carboxymethyl chitosan solution after 1 day of surgery. All these results suggested that the developed biodegradable hydrogel might have potential application in the prevention of postoperative adhesion.

Effects of alcohol on pericardial adhesion formation in hypercholesterolemic swine

OBJECTIVE

Reoperative cardiac surgery is complicated in part because of extensive adhesions encountered during the second operation. The purpose of this study was to examine the effects of alcohol with and without resveratrol (red wine vs vodka) on postoperative pericardial adhesion formation in a porcine model of hypercholesterolemia and chronic myocardial ischemia.

METHODS

Male Yorkshire swine were fed a high-cholesterol diet to simulate conditions of coronary artery disease followed by surgical placement of an ameroid constrictor to induce chronic ischemia. Postoperatively, control pigs continued their high-cholesterol diet alone, whereas the 2 experimental groups had diets supplemented with red wine or vodka. Seven weeks after ameroid placement, all animals underwent reoperative sternotomy.

RESULTS

Compared with controls, pericardial adhesion grade was markedly reduced in the vodka group, whereas there was no difference in the wine group. Intramyocardial fibrosis was significantly reduced in the vodka group compared with controls. There was no difference in expression of proteins involved in focal adhesion formation between any groups (focal adhesion kinase, integrin alpha-5, integrin beta-1, paxillin, vinculin, protein tyrosine kinase 2, protein kinase C ε, and phosphorylated protein kinase C ε). The wine group exhibited elevated C-reactive protein levels versus the control and vodka groups.

CONCLUSIONS

Postoperative vodka consumption markedly reduced the formation of pericardial adhesions and intramyocardial fibrosis, whereas red wine had no effect. Analysis of protein expression did not reveal any obvious explanation for this phenomenon, suggesting a post-translational effect of alcohol on fibrous tissue deposition. The difference in adhesion formation in the vodka versus wine groups may be due to increased inflammation in the wine group.