Tizanidine (Zanaflex): a muscle relaxant that may prolong the QT interval by blocking IKr

Nanomaterials in Drug Delivery: Strengths and Opportunities in Medicine

There is a myriad of diseases that plague the world ranging from infectious, cancer and other chronic diseases with varying interventions. However, the dynamism of causative agents of infectious diseases and incessant mutations accompanying other forms of chronic diseases like cancer, have worsened the treatment outcomes. These factors often lead to treatment failure via different drug resistance mechanisms. More so, the cost of developing newer drugs is huge. This underscores the need for a paradigm shift in the drug delivery approach in order to achieve desired treatment outcomes. There is intensified research in nanomedicine, which has shown promises in improving the therapeutic outcome of drugs at preclinical stages with increased efficacy and reduced toxicity. Regardless of the huge benefits of nanotechnology in drug delivery, challenges such as regulatory approval, scalability, cost implication and potential toxicity must be addressed via streamlining of regulatory hurdles and increased research funding. In conclusion, the idea of nanotechnology in drug delivery holds immense promise for optimizing therapeutic outcomes. This work presents opportunities to revolutionize treatment strategies, providing expert opinions on translating the huge amount of research in nanomedicine into clinical benefits for patients with resistant infections and cancer.

Nanomedicine-based commercial formulations: current developments and future prospects

Background

In recent decades, there has been a considerable increase in the number of nanomedicine-based formulations, and their advantages, including controlled/targeted drug delivery with increased efficacy and reduced toxicity, make them ideal candidates for therapeutic delivery in the treatment of complex and difficult-to-treat diseases, such as cancer.

Areas covered

This review focuses on nanomedicine-based formulation development, approved and marketed nanomedicines, and the challenges faced in nanomedicine development as well as their future prospects.

Expert opinion

To date, the Food and Drug Administration and the European Medicines Agency have approved several nanomedicines, which are now commercially available. However, several critical challenges, including reproducibility, proper characterization, and biological evaluation, e.g., via assays, are still associated with their use. Therefore, rigorous studies alongside stringent guidelines for effective and safe nanomedicine development and use are still warranted. In this study, we provide an overview of currently available nanomedicine-based formulations. Thus, the findings here reported may serve as a basis for further studies regarding the use of these formulations for therapeutic purposes in near future.

Intrathecal and Oral Baclofen Use in Adults With Spinal Cord Injury: A Systematic Review of Efficacy in Spasticity Reduction, Functional Changes, Dosing, and Adverse Events

OBJECTIVE

To examine the efficacy, dosing, and safety profiles of intrathecal and oral baclofen in treating spasticity after spinal cord injury (SCI).

DATA SOURCES

PubMed and Cochrane Databases were searched from 1970-2018 with keywords baclofen, spinal cord injury, and efficacy.

STUDY SELECTION

The database search yielded 588 sources and 10 additional relevant publications. After removal of duplicates, 398 publications were screened.

DATA EXTRACTION

Data were extracted using the following population, intervention, comparator, outcomes, and study designs criteria: studies including adult patients with SCI with spasticity; the intervention could be oral or intrathecal administration of baclofen; selection was inclusive for control groups, surgical management, rehabilitation, and alternative pharmaceutical agents; outcomes were efficacy, dosing, and adverse events. Randomized controlled trials, observational studies, and case reports were included. Meta-analyses and systematic reviews were excluded.

DATA SYNTHESIS

A total of 98 studies were included with 1943 patients. Only 4 randomized, double-blinded, and placebo-controlled trials were reported. Thirty-nine studies examined changes in the Modified Ashworth Scale (MAS; 34 studies) and Penn Spasm scores (Penn Spasm Frequency; 19 studies), with average reductions of 1.7±1.3 and 1.6±1.4 in individuals with SCI, respectively. Of these data, a total of 6 of the 34 studies (MAS) and 2 of the 19 studies (Penn Spasm Frequency) analyzed oral baclofen. Forty-three studies addressed adverse events with muscle weakness and fatigue frequently reported.

CONCLUSIONS

Baclofen is the most commonly-prescribed antispasmodic after SCI. Surprisingly, there remains a significant lack of large, placebo-controlled, double-blinded clinical trials, with most efficacy data arising from small studies examining treatment across different etiologies. In the studies reviewed, baclofen effectively improved spasticity outcome measures, with increased efficacy through intrathecal administration. Few studies assessed how reduced neural excitability affected residual motor function and activities of daily living. A host of adverse events were reported that may negatively affect quality of life. Comparative randomized controlled trials of baclofen and alternative treatments are warranted because these have demonstrated promise in relieving spasticity with reduced adverse events and without negatively affecting residual motor function.

Signals of Muscle Relaxant Drug Interactions Associated with Unintentional Traumatic Injury: A Population-Based Screening Study

BACKGROUND

Use of muscle relaxants is rapidly increasing in the USA. Little is understood about the role of drug interactions in the known association between muscle relaxants and unintentional traumatic injury, a clinically important endpoint causing substantial morbidity, disability, and death.

OBJECTIVE

We examined potential associations between concomitant drugs (i.e., precipitants) taken with muscle relaxants (affected drugs, i.e., objects) and hospital presentation for unintentional traumatic injury.

METHODS

In a series of self-controlled case series studies, we screened to identify drug interaction signals for muscle relaxant + precipitant pairs and unintentional traumatic injury. We used Optum's de-identified Clinformatics^® Data Mart Database, 2000-2019. We included new users of a muscle relaxant, aged 16-90 years, who were dispensed at least one precipitant drug and experienced an unintentional traumatic injury during the observation period. We classified each observation day as precipitant exposed or precipitant unexposed. The outcome was an emergency department or inpatient discharge diagnosis for unintentional traumatic injury. We used conditional Poisson regression to estimate rate ratios adjusting for time-varying confounders and then accounted for multiple estimation via semi-Bayes shrinkage.

RESULTS

We identified 74,657 people who initiated muscle relaxants and experienced an unintentional traumatic injury, in whom we studied concomitant use of 2543 muscle relaxant + precipitant pairs. After adjusting for time-varying confounders, 16 (0.6%) pairs were statistically significantly and positively associated with injury, and therefore deemed signals of a potential drug interaction. Among signals, semi-Bayes shrunk, confounder-adjusted rate ratios ranged from 1.29 (95% confidence interval 1.04-1.62) for baclofen + sertraline to 2.28 (95% confidence interval 1.14-4.55) for methocarbamol + lamotrigine.

CONCLUSIONS

Using real-world data, we identified several new signals of potential muscle relaxant drug interactions associated with unintentional traumatic injury. Only one among 16 signals is currently reported in a major drug interaction knowledge base. Future studies should seek to confirm or refute these signals.

Development of Pharmaceutical Nanomedicines: From the Bench to the Market

Nanotechnology plays a significant role in the field of medicine and in drug delivery, mainly due to the major limitations affecting the conventional pharmaceutical agents, and older formulations and delivery systems. The effect of nanotechnology on healthcare is already being felt, as various nanotechnology applications have been developed, and several nanotechnology-based medicines are now on the market. Across many parts of the world, nanotechnology draws increasing investment from public authorities and the private sector. Most conventional drug-delivery systems (CDDSs) have an immediate, high drug release after administration, leading to increased administration frequency. Thus, many studies have been carried out worldwide focusing on the development of pharmaceutical nanomedicines for translation into products manufactured by local pharmaceutical companies. Pharmaceutical nanomedicine products are projected to play a major role in the global pharmaceutical market and healthcare system. Our objectives were to examine the nanomedicines approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in the global market, to briefly cover the challenges faced during their development, and to look at future perspectives. Additionally, the importance of nanotechnology in developing pharmaceutical products, the ideal properties of nanocarriers, the reasons behind the failure of some nanomedicines, and the important considerations in the development of nanomedicines will be discussed in brief.

Nanopharmaceutical-based regenerative medicine: a promising therapeutic strategy for spinal cord injury

Spinal cord injury (SCI) is a neurological disorder that can lead to loss of perceptive and athletic function due to the severe nerve damage. To date, pieces of evidence detailing the precise pathological mechanisms in SCI are still unclear. Therefore, drug therapy cannot effectively alleviate the SCI symptoms and faces the limitations of systemic administration with large side effects. Thus, the development of SCI treatment strategies is urgent and valuable. Due to the application of nanotechnology in pharmaceutical research, nanopharmaceutical-based regenerative medicine will bring colossal development space for clinical medicine. These nanopharmaceuticals (i.e. nanocrystalline drugs and nanocarrier drugs) are designed using different types of materials or bioactive molecules, so as to improve the therapeutic effects, reduce side effects, and subtly deliver drugs, etc. Currently, an increasing number of nanopharmaceutical products have been approved by drug regulatory agencies, which has also prompted more researchers to focus on the potential treatment strategies of SCI. Therefore, the purpose of this review is to summarize and elaborate the research progress as well as the challenges and future of nanopharmaceuticals in the treatment of SCI, aiming to promote further research of nanopharmaceuticals in SCI.

Tizanidine hydrochloride exhibits a cytotoxic effect on osteosarcoma cells through the PI3K/AKT signaling pathway

Objectives

α2-adrenergic receptors are reportedly involved in cancer cell proliferation, invasion, and apoptosis through regulation of diverse molecules, which implies that it contributes to tumor progression. However, the functional significance of α2-adrenergic receptors in osteosarcoma (OS) is unclear. Tizanidine hydrochloride (THC), an α2-adrenergic receptor agonist, is often used to alleviate symptoms of spasticity. This study investigated the functional implications of THC treatment on human OS cells and the underlying mechanisms of resulting changes.

Methods

The proliferation of U2 OS cells was assessed by Cell Counting Kit-8; the migration and invasion capacities of U2 OS cells were then analyzed by transwell assay. Moreover, apoptosis in U2 OS cells was evaluated by flow cytometry and western blot analyses. Additionally, expression levels of key proteins in the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway were measured.

Results

THC inhibited the proliferation, migration, and invasion of U2 OS cells, but promoted apoptosis within these cells. Expression levels of p-AKT, p-mTOR, and p-P70S6K were reduced by exposure to THC, suggesting involvement of PI3K/AKT signaling in THC-induced cytotoxicity within OS cells.

Conclusions

THC may play a novel role in OS cell cytotoxicity, and these findings suggest a potent therapeutic strategy for OS treatment.

Pain medication and long QT syndrome

Long QT syndrome is a cardiac repolarization disorder and is associated with an increased risk of torsades de pointes. The acquired form is most often attributable to administration of specific medications and/or electrolyte imbalance. This review provides insights into the risk for QT prolongation associated with drugs frequently used in the treatment of chronic pain. In the field of pain medicine all the major drug classes (i.e. NSAIDs, opioids, anticonvulsive and antidepressant drugs, cannabinoids, muscle relaxants) contain agents that increase the risk of QT prolongation. Other substances, not used in the treatment of pain, such as proton pump inhibitors, antiemetics, and diuretics are also associated with long QT syndrome. When the possible benefits of therapy outweigh the associated risks, slow dose titration and electrocardiography monitoring are recommended.

Serum concentration of eperisone hydrochloride correlates with QT interval

BACKGROUND

Eperisone hydrochloride is a centrally acting muscle relaxant prescribed for muscle stiffness that acts by depressing the activities of α and γ efferent neurons in the spinal cord and supraspinal structures. Although a case of eperisone-induced severe QT prolongation had been reported, the relationship between serum eperisone concentration and QT interval remains obscure.

OBJECTIVE

The aim of this study was to investigate the relationship between serum eperisone concentration and QT interval.

METHODS

Four patients who overdosed on eperisone were admitted to our hospital between January 2010 and December 2011. We took simultaneous serial measurements of serum eperisone concentration and QT interval in the intensive care unit. In total, 22 measurement points were plotted for these patients. We analyzed the correlation between the serum eperisone concentration and corrected QT (QTc) interval.

RESULTS

Three men and one woman (mean age, 50 years) overdosed on eperisone with an average dose of 3087.5 mg (therapeutic dose, 150 mg/day). The mean QTc interval at arrival was 592 ms (range, 444-825 ms), and the mean serum eperisone concentration at arrival was 1257.5 ng/mL (range, 14.5-4120.0 ng/mL). The correlation coefficient was 0.833 between serum eperisone concentration and QTc interval (P < .001).

CONCLUSION

Serum eperisone concentration correlates with QTc interval in patients who overdose on eperisone.

Azithromycin, cardiovascular risks, QTc interval prolongation, torsade de pointes, and regulatory issues: A narrative review based on the study of case reports

Over the past year, three articles have appeared in the New England Journal of Medicine describing conflicting findings about azithromycin and cardiac safety, particular azithromycin-induced QTc interval prolongation and torsade de pointes. The FDA wants healthcare providers to consider azithromycin-induced fatal cardiac arrhythmias for patients already at risk for cardiac death and other potentially arrhythmogenic cardiovascular conditions. In a systematic review of case reports we sought to determine factors that link to azithromycin-induced/associated QTc interval prolongation and torsade de pointes. We found 12 cases: seven female and five male. Of the nine adults with reported azithromycin doses, concurrent QTc interval measurement, and without congenital long QT syndrome, we found no significant relationship between dose and QTc interval duration. Additional risk factors were female sex, older age, heart disease, QTc interval prolonging drugs and metabolic inhibitors, hypokalemia, and bradycardia. All 12 subjects had at least two additional risk factors. Elderly women with heart disease appear to be at particularly risk for drug-related QTc interval prolongation and torsade de pointes.