Granisetron in the control of radiotherapy-induced nausea and vomiting: a comparison with other antiemetic therapies

Pyrazole-containing pharmaceuticals: target, pharmacological activity, and their SAR studies

Pyrazole is a five-membered heterocycle bearing two adjacent nitrogen atoms. Both pharmaceutical agents and natural products with pyrazole as a nucleus have exhibited a broad spectrum of biological activities. In the last few decades, more than 40 pyrazole-containing drugs have been approved by the FDA for the treatment of a broad range of clinical conditions including celecoxib (anti-inflammatory), CDPPB (antipsychotic), difenamizole (analgesic), etc. Owing to the unique physicochemical properties of the pyrazole core, pyrazole-containing drugs may exert better pharmacokinetics and pharmacological effects compared with drugs containing similar heterocyclic rings. The purpose of this paper is to provide an overview of all the existing drugs bearing a pyrazole nucleus that have been approved or in clinical trials, involving their pharmacological activities and SAR studies.

An Overview of Radiation-Induced Nausea and Vomiting

BACKGROUND

Radiation-induced nausea and vomiting (RINV) is common occurrence in cancer patients treated with radiotherapy. When radiation is prescribed to certain sites, it can lead to retching, vomiting, and nausea that can lead to impairments on quality of life and even effect adherence to treatment regimes. The present study reports select literature examining RINV phenomena and reviews mechanisms of RINV as well as current management strategies.

METHODS

A literature search was conducted on PubMed using search strategies such as "radiation-induced nausea vomiting," "RINV," and "radiation and antiemetics." The search was limited to articles published from January 2000 to April 2016 and those that involved humans and were published in English. Information regarding emetic risk of each treatment and management strategies used were extracted from each article.

RESULTS

A total of 25 articles were included in this select review. The current evidence regarding the standard antiemetics for RIINV are discussed, as well as upcoming therapies and future potential endeavors.

CONCLUSIONS

Cancer patients treated with emetogenic radiotherapy are at risk of experiencing RINV. RINV has the potential to impact patient quality of life and treatment delivery and optimal prophylactic strategies should be implemented, particularly in radiation naïve patients. More awareness on these topics is warranted, so that standard antiemetic regimens can be used in both the prophylactic and rescue settings.

Formulation of Convenient, Easily Scalable, and Efficient Granisetron HCl Intranasal Droppable Gels

Deacetylated gellan gum and two sodium alginate polymer types were used each at three concentrations in the suitable range for their sol-gel transition. The prepared nine droppable gels were evaluated in vitro, ex vivo through sheep nasal mucosa, as well as in vivo in comparison to drug solution given intravenously and orally at the same dose. The prepared formulas gelled instantaneously in simulated nasal fluid and the obtained gels sustained their shear thinning and thixotropic behavior up to 48 h. Polymer type and concentration had significant effects on the apparent viscosities and the in vitro release profile of granisetron from the prepared gels. The drug release data best fitted a modified Higuchi equation with initial burst and followed Fickian diffusion mechanism. A 0.5% gellan-gum-based formula sustained the in vitro drug release up to 3 h and enhanced the drug permeation without need for an enhancer. The histopatholgical study revealed the safety of the tested formula. Intranasal delivery recorded double the drug bioavailabilty in comparison to the oral route. It had an absolute bioavailability of 0.6539 and the maximum plasma drug concentration reached after 1.5 h. The developed formula could be promising for the management of chemotherapy-induced nausea and vomiting regarding its improved bioavailability, patient acceptability, and ease of production.

Moderate to severe nausea in radioactive iodine (RAI) therapy is associated with the RAI dose per body weight and was not prevented by ramosetron

To retrospectively analyze the individual risk factors for radioactive iodine (RAI)-associated nausea and vomiting, and to examine the anti-emetic effect of ramosetron (5-hydroxytryptamine-3 receptor antagonist) in RAI therapy. Patients with differentiated thyroid carcinoma who underwent first-time RAI therapy at Nagasaki University Hospital between January 2009 and 2013 were included (N = 81). As a routine treatment, all patients were administered 30 mg of domperidone per day. Patients who underwent RAI therapy between April 2011 and January 2013 were also administered 0.1 mg of ramosetron per day in addition to domperidone. Nausea and vomiting were evaluated based on Common Terminology Criteria for Adverse Events version 4.0. RAI-associated nausea and vomiting of any grade were seen in 37.0 and 6.2 % of patients in total, respectively. Moderate to severe nausea (grade 2–3) was seen in 22.2 % of patients and associated with the dose of RAI per body weight (odds ratio = 1.046, p = 0.013), but not with the use of ramosetron, in multivariate logistic regression analysis. We have identified the dose of RAI per body weight to be an individual risk factor associated with moderate to severe RAI-associated nausea. This study failed to show that the combined use of ramosetron and domperidone reduced the frequency of RAI-associated nausea and vomiting.

Study on the interactions of antiemetic drugs and 12-tungstophosphoric acid by absorption and resonance Rayleigh scattering spectra and their analytical applications

In 0.1 mol L(-1) HCl medium, antiemetic drugs (ATM), such as granisetron hydrochloride (GS) and tropisetron hydrochloride (TS), reacted with H(3)PW(12)O(40)·nH(2)O and formed 3:1 ion-association complex of [(ATM)(3)PW(12)O(40)], then self-aggregated into nanoparticles-[(ATM)(3)PW(12)O(40)](n) with an average size of 100 nm. The reaction resulted in the enhancement of resonance Rayleigh scattering (RRS) and the absorption spectra. The increments of scattering intensity (ΔI(RRS)) and the change of absorbance (ΔA) were both directly proportional to the concentrations of ATM in certain ranges. Accordingly, two new RRS and spectrophotometric methods were proposed for ATM detection. The detection limits (3σ) of GS and TS were 3.2 ng mL(-1) and 4.0 ng mL(-1)(RRS method), 112.5 ng mL(-1) and 100.0 ng mL(-1)(spectrophotometric method). These two methods were applied to determine GS in orally disintegrating tablets and the results were in good agreement with the official method. The ground-state geometries and electronic structures of GS and TS were optimized by the hybrid density functional theory (DFT) method and the shape of [(ATM)(3)PW(12)O(40)](n) was characterized by atomic force microscopy (AFM). Take the RRS method with higher sensitivity as an example, the reaction mechanism and the reasons for enhancement of scattering were discussed.