Topical Fixed-Dose Combinations: A Way of Progress for Pain Management?

Phytochemistry and Biological Profile of Gaultheria procumbens L. and Wintergreen Essential Oil: From Traditional Application to Molecular Mechanisms and Therapeutic Targets

Gaultheria procumbens L. is a medicinal plant whose aerial parts (leaves, stems, and fruits) and methyl salicylate-rich essential oil (wintergreen oil) are used in phytotherapy to treat inflammation, muscular pain, and infection-related disorders. This overview summarises the current knowledge about ethnobotany, phytochemistry, pharmacology, molecular mechanisms, biocompatibility, and traditional use of G. procumbens and the wintergreen oil distilled from different plant organs. Over 70 hydrophilic compounds, including methyl salicylate glycosides, flavonoids, procyanidins, free catechins, caffeoylquinic acids, and simple phenolic acids, have been identified in G. procumbens plant parts. Moreover, aliphatic compounds, triterpene acids, and sterols have been revealed in lipophilic fractions. Furthermore, over 130 volatile compounds have been detected in wintergreen oil with dominating methyl salicylate (96.9-100%). The accumulated research indicates that mainly hydrophilic non-volatiles are responsible for the pharmacological effects of G. procumbens, primarily its potent anti-inflammatory, antioxidant, and photoprotective activity, with mechanisms verified in vitro and ex vivo in cellular and cell-free assays. The biological effectiveness of the dominant methyl salicylate glycoside-gaultherin-has also been confirmed in animals. Wintergreen oil is reported as a potent anti-inflammatory agent exhibiting moderate antioxidant and antimicrobial activity in vitro and significant insecticidal and larvicidal capacity. Together, G. procumbens accumulate a diverse fraction of polyphenols, triterpenes, and volatiles with validated in vitro and ex vivo biological activity but with the absence of in vivo studies, especially clinical trials concerning effective dose determination and toxicological verification and technological research, including drug formulation.

Pharmacokinetic and Pharmacodynamic Drug-Drug Interactions: Research Methods and Applications

Because of the high research and development cost of new drugs, the long development process of new drugs, and the high failure rate at later stages, combining past drugs has gradually become a more economical and attractive alternative. However, the ensuing problem of drug-drug interactions (DDIs) urgently need to be solved, and combination has attracted a lot of attention from pharmaceutical researchers. At present, DDI is often evaluated and investigated from two perspectives: pharmacodynamics and pharmacokinetics. However, in some special cases, DDI cannot be accurately evaluated from a single perspective. Therefore, this review describes and compares the current DDI evaluation methods based on two aspects: pharmacokinetic interaction and pharmacodynamic interaction. The methods summarized in this paper mainly include probe drug cocktail methods, liver microsome and hepatocyte models, static models, physiologically based pharmacokinetic models, machine learning models, in vivo comparative efficacy studies, and in vitro static and dynamic tests. This review aims to serve as a useful guide for interested researchers to promote more scientific accuracy and clinical practical use of DDI studies.

Topical Fixed-Dose Combinations: Current in vitro methodologies for pre-clinical development

The combination of two or more active pharmaceutical ingredients in the same dosage form - fixed-dose combination products - for topical administration represents a promising therapeutic approach for treating several pathologies, including pain. The pre-clinical development of fixed-dose combination products aims to characterize the interactions between the different APIs and ensure that the final medicinal product has the required safety characteristics. To this end, there are several regulatory accepted in vitro tests to assess the safety of medicinal products intended for cutaneous administration. In turn, the evaluation of anti-inflammatory activity should be based on models described in the scientific literature, as there are no models fully validated by competent entities. Therefore, the present work presents the information regarding accepted in vitro tests to assess the safety of topical products and the most used methods to assess anti-inflammatory activity. Additionally, a new approach to select a fixed-dose combination product with the potential to enhance the therapeutic effects of the individual active pharmaceutical ingredients is rationalized by integrating the overall effects on several targets relevant for inflammation and pain management in one numeric index.

Student nurses' pain knowledge and attitudes towards pain management over the last 20 years: A systematic review

OBJECTIVE

To discover if nursing students have improved their level of pain knowledge and their attitudes towards pain management over the last 20 years.

DESIGN

Systematic review utilising the Kable, Pich, and Maslin-Prothero 12 step approach to document a search strategy.

DATA SOURCES

A search was conducted from 2000 to 2020 using CINAHL, PubMed, Embase and ProQuest.

REVIEW METHODS

Studies exploring the level of pain management knowledge and attitudes of nursing students were included. The Critical Review Form - Quantitative Studies provided the appraisal framework (Law et al., 1998). A narrative synthesis of eligible studies was undertaken.

RESULTS

Six studies with a total of 1454 participants were included. The studies demonstrated that nursing students have not improved their level of pain knowledge and attitudes towards pain management in the last 20 years. Whilst many nursing students thought they possessed adequate pain knowledge, the studies all demonstrated that their pain knowledge is lacking and that they do not have appropriate attitudes towards pain. Students did not recognise the patient who was not grimacing as being in pain despite the patient report of pain.

CONCLUSIONS

These findings support the notion that nursing education does not include sufficient focus on pain identification and management. Alignment of nursing pain education with the curriculum developed in 1993 by the International Association for the Study of Pain is needed to ensure nurses have appropriate knowledge so that patients can receive effective pain management.

Topical Lidocaine plus Diclofenac as a Local Anesthetic Agent in Central Venous Catheterization; a Randomized Controlled Clinical Trial

Introduction:

Various methods of analgesia can be used to reduce or prevent procedural pain in emergency department (ED). This study aimed to evaluate the effectiveness of topical lidocaine-diclofenac combination compared to lidocaine-prilocaine combination (Xyla-P) in reduction of the pain during central venous catheter (CVC) insertion.

Methods:

In this randomized clinical trial, 100 adult patients requiring CVC insertion in the ED were enrolled. These patients were randomly divided into two groups. The site of CVC insertion was covered with 2 g of topical Xyla-P cream in the first group, and 2 g of topical lidocaine-diclofenac cream in the second group. The primary outcome was the pain during CVC implantation. The secondary outcomes were physician satisfaction and the incidence of side effects.

Results:

 On the visual analog scale (VAS), the pain score during CVC insertion was significantly lower in the second group (p = 0.027). However, there was no difference in pain scores during lidocaine injection between the two groups (p = 0.386). Also, there was no significant difference in the rate of side effects between the two groups (p = 1.0). The physician’s satisfaction with the first group was significantly lower than the second group (p = 0.042).

Conclusion:

Although the CVC insertion pain was significantly lower in patients who received the topical combination of Lidocaine plus Diclofenac, there was no clinically important difference between the two groups and both topical anesthetics were effective and safe in reducing pain intensity. Also, lidocaine-diclofenac combination cream was more cost-effective than Xyla-P cream.