Excipients in medicinal products used in gastroenterology as a possible cause of side effects.

Although most adverse drug reactions are caused by the active substances, excipients may sometimes affect the safety profile of a medicinal product. The aim of this review is twofold: (1) To identify the excipients most frequently contained in oral medicinal products marketed in Italy for gastrointestinal indications, and to evaluate the main safety concerns, considering both intrinsic toxicity and patient-related risk factors. (2) To analyze possible differences with medicinal products marketed in the United Kingdom and USA in terms of excipients and relevant warnings reported in the label. We identified excipients with potential impact on safety profile and calculated frequency of use of each identified excipient in 98 selected medicinal products. We discussed possible safety concerns in clinical practice. We also analyzed US and UK Summary of Products Characteristics (SmPC) of oral gastrointestinal products by searching in appropriate collections of regulatory agencies. Eleven excipients with a safety impact were identified (sucrose, saccharin, aspartame, sorbitol, mannitol, lactose, ethanol, propylene glycol, parabens, menthol and silica) and no substantial differences were found between drugs marketed in the three countries concerning excipient content. Warnings were more detailed in the SmPC of UK or USA products rather than Italian products. Information about pharmaceutical excipients with known effects is important in clinical practice, but the frequent lack of details in the related section of the SmPCs makes it difficult for health professionals to provide relevant advice. The availability of alternative products of the same therapeutic class, but lacking specific excipient(s) should be considered in selected patients.

Proinflammatory role of vasopressin through V1b receptors in hapten-induced experimental colitis in rodents: implication in IBD.

Vasopressin and its receptors modulate several gut functions, but their role in intestinal inflammation is unknown. Our aims were to determine 1) the localization of V1b receptors in human and rodent colon, 2) the role of vasopressin and V1b receptors in experimental colitis using two approaches: V1b⁻(/)⁻ mice and a selective V1b receptor antagonist, SSR149415, and 3) the mechanisms involved. V1b receptors were localized in normal and inflamed colon from humans and rats. Experimental colitis was induced in rats and mice and some groups were treated before or after colitis induction with oral SSR149415 (3-30 mg/kg). Other groups of mice were submitted to dehydration to increase vasopressin plasma levels, prior to colitis induction. Body weight, damage scores, MPO, and TNF-α tissue levels were determined. Finally, colonic segments of wild-type (WT) and V1b⁻(/)⁻ mice were mounted in Ussing chambers and paracellular permeability in response to vasopressin was studied. V1b receptors were expressed in enterocytes and ganglia cells of the enteric nervous system of human and rat intestine. Expression levels were independent from inflammatory status. Colitis was less severe in rodents treated by either preventive or curative SSR149415 and in V1b⁻(/)⁻ mice. 2,4,6-Trinitrobenzene sulfonic acid induced a strong mortality in dehydrated animals that was reversed by preventive SSR149415 or mast cell stabilizer. Vasopressin significantly increased paracellular permeability in WT, but not in V1b⁻(/)⁻ mice. Preincubation of colon tissues with SSR149415 abolished the vasopressin effect. Similarly, vasopressin had no effect in colonic preparations from WT mice pretreated with mast cell stabilizers. Vasopressin, through V1b receptor interaction, has proinflammatory properties linked to mast cell activation and downstream alterations of the colonic epithelial barrier. These findings underline the potential interest of V1b receptor blockers in gut inflammatory diseases.

Non-peptidyl low molecular weight radical scavenger IAC attenuates DSS-induced colitis in rats.

AIM: To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate (IAC) in the dextran sodium sulphate (DSS) experimental model of ulcerative colitis. METHODS: Colitis was induced in Sprague Dawley male rats by administration of 5% DSS in drinking water. IAC (30 mg/kg, lipophilic or hydrophilic form) was administered daily (orally or ip) for 6 d until sacrifice. Colonic damage was assessed by means of indirect (Disease Activity Index score) and direct measures (macroscopic and microscopic scores) and myeloperoxidase (MPO) activity. Neutrophil infiltration within the tissue and glutathione S-transferase activity were also investigated. RESULTS: DSS-induced colitis impaired body weight gain and markedly increased all inflammatory parameters. Six-day treatment with lipophilic IAC significantly reduced intestinal damage caused by inflammation, induced a down-regulation in MPO activity (0.72 +/- 0.12 and 0.45 +/- 0.12 with lipophilic IAC po and ip, respectively, vs 1.10 +/- 0.27 in untreated DSS colitis animals) and minimized DSS-induced neutrophil infiltration, while hydrophilic IAC administered orally did not ameliorate DSS-induced damage. CONCLUSION: These results support the hypothesis that reactive oxygen metabolites contribute to inflammation and that the radical scavenger IAC has therapeutic potential in inflammatory bowel disease.

Anticancer drugs and cardiotoxicity: Insights and perspectives in the era of targeted therapy.

Drug-induced cardiotoxicity is emerging as an important issue among cancer survivors. For several decades, this topic was almost exclusively associated with anthracyclines, for which cumulative dose-related cardiac damage was the limiting step in their use. Although a number of efforts have been directed towards prediction of risk, so far no consensus exists on the strategies to prevent and monitor chemotherapy-related cardiotoxicity. Recently, a new dimension of the problem has emerged when drugs targeting the activity of certain tyrosine kinases or tumor receptors were recognized to carry an unwanted effect on the cardiovascular system. Moreover, the higher than expected incidence of cardiac dysfunction occurring in patients treated with a combination of old and new chemotherapeutics (e.g. anthracyclines and trastuzumab) prompted clinicians and researchers to find an effective approach to the problem. From the pharmacological standpoint, putative molecular mechanisms involved in chemotherapy-induced cardiotoxicity will be reviewed. From the clinical standpoint, current strategies to reduce cardiotoxicity will be critically addressed. In this perspective, the precise identification of the antitarget (i.e. the unwanted target causing heart damage) and the development of guidelines to monitor patients undergoing treatment with cardiotoxic agents appear to constitute the basis for the management of drug-induced cardiotoxicity.

The beta3-adrenoceptor as a therapeutic target: current perspectives.

beta(3)-Adrenoceptors (beta(3)-ARs) are located not only on the plasma membrane of both white and brown adipocytes, but also exist in human heart, gall bladder, gastrointestinal tract, prostate, urinary bladder detrusor, brain and in near-term myometrium. They are now recognized as an attractive target for drug discovery and several efforts have been made in this field to understand their function and regulation in different human tissues. The aim of this review is to highlight the functional role of beta(3)-ARs as well as to discuss their potential for drug development.

Effects of the non-peptidyl low molecular weight radical scavenger IAC in DNBS-induced colitis in rats.

Intestinal inflammation is accompanied by excessive production of reactive oxygen and nitrogen radical species because of the massive infiltration of polymorphonuclear and mononuclear leukocytes. Antioxidant compounds seem to protect against experimental colitis. Here we investigated the effects of the innovative non-peptidyl, low molecular weight radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate (IAC), which is highly reactive with most oxygen, nitrogen and carbon centred radicals and is easily distributed in cell membranes and intra-extra cellular compartments, in the DNBS model of colitis. Colitis was induced in male SD rats by intrarectal administration of DNBS (15 mg/rat). IAC (30 mg/kg b.w., hydrophilic or lipophilic form) was administered daily (orally or i.p.) starting from the day before the induction of colitis for 7 days (n=6-8 per group). Colonic damage was assessed by means of macroscopic and histological scores, myeloperoxidase activity (MPO) and TNF-alpha tissue levels. Colitis impaired body weight gain and markedly increased all inflammatory parameters. IAC significantly counteracted the reduction in body weight gain, decreased colonic damage and inflammation and TNF-alpha levels in DNBS-colitis. The antioxidant IAC significantly ameliorates experimental colitis in rats. This strengthens the notion that antioxidant compounds may have therapeutic potential in inflammatory bowel disease.

Protection from DNBS-induced colitis by the tachykinin NK(1) receptor antagonist SR140333 in rats.

Inflammation is known to be associated with changes in tachykinin expression both in human and animal models: substance P and NK(1) receptor expression are increased in patients with inflammatory bowel disease, and similar changes are reported in experimental models of inflammation. We investigated the effect of the tachykinin NK(1) receptor antagonist SR140333 (10 mg/kg orally) on 2,4-dinitrobenzene sulfonic acid (DNBS)-induced colitis in rats. Colonic damage was assessed by means of macroscopic and microscopic scores, myeloperoxidase activity (MPO) and TNF-alpha tissue levels on day 6 after induction of colitis. An enzyme immunoassay technique was used to measure colonic substance P levels. DNBS administration impaired body weight gain and markedly increased all inflammatory parameters as well as colonic tissue levels of substance P. Treatment with SR140333 significantly counteracted the impairment in body weight gain, decreased macroscopic and histological scores and reduced colonic myeloperoxidase activity and TNF-alpha tissue levels. Colonic tissue levels of substance P were also reduced by SR140333, although this effect did not reach statistical significance. In conclusion, treatment with SR140333 protects from DNBS-induced colitis in rats. These results suggest a role for NK(1) receptors and substance P in the development of intestinal inflammation and indicate tachykinin receptors as a potential pharmacological target in the treatment of inflammatory bowel disease.