Review of the Pharmacological Properties and Clinical Usefulness of Muscarinic Agonists for Xerostomia in Patients with Sjögren's Syndrome

Synthetic Routes to Approved Drugs Containing a Spirocycle

The use of spirocycles in drug discovery and medicinal chemistry has been booming in the last two decades. This has clearly translated into the landscape of approved drugs. Among two dozen clinically used medicines containing a spirocycle, 50% have been approved in the 21st century. The present review focuses on the notable synthetic routes to such drugs invented in industry and academia, and is intended to serve as a useful reference source of synthetic as well as general drug information for researchers engaging in the design of new spirocyclic scaffolds for medicinal use or embarking upon analog syntheses inspired by the existing approved drugs.

Salivary gland function, development, and regeneration

Salivary glands produce and secrete saliva, which is essential for maintaining oral health and overall health. Understanding both the unique structure and physiological function of salivary glands, as well as how they are affected by disease and injury, will direct the development of therapy to repair and regenerate them. Significant recent advances, particularly in the OMICS field, increase our understanding of how salivary glands develop at the cellular, molecular, and genetic levels: the signaling pathways involved, the dynamics of progenitor cell lineages in development, homeostasis, and regeneration, and the role of the extracellular matrix microenvironment. These provide a template for cell and gene therapies as well as bioengineering approaches to repair or regenerate salivary function.

Xerostomia: an immunotherapy-related adverse effect in cancer patients

PURPOSE

Xerostomia is an underrecognized adverse effect of immunotherapy (IO) that can significantly impact patients' quality of life by leading to poor nutritional status, dental caries, and oral candidiasis. The purpose of this case series was to describe the onset, severity, clinical course, and management of IO-induced xerostomia.

METHODS

This was a retrospective case series conducted at an outpatient cancer center. Data collection was conducted via chart review. The severity of dry mouth symptoms was graded using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

RESULTS

Six patients with advanced solid tumors who received a PD-1 inhibitor or PD-1/CTLA-4 inhibitor combination therapy were evaluated. The median time to onset of xerostomia was 4.5 months overall, though symptoms developed sooner in patients who received IO as subsequent-line therapy (median = 1.9 months). All patients developed other immune-related adverse events (IRAEs) such as hypothyroidism. Five patients (83%) had grade 2 dry mouth symptoms, and similarly, 5 patients eventually required prescription medications such as sialogogues and topical or systemic corticosteroids to alleviate symptoms. Two patients (33%) required interruptions in IO. All 3 patients who received cevimeline noticed improvement in symptoms, and one patient who received prednisone dosed at 1 mg/kg/day tapered over 5 weeks also experienced significant relief.

CONCLUSION

While the optimal management of IO-induced xerostomia has not yet been established by national guidelines, increased awareness can prompt faster initiation of supportive care measures that can prevent significant discomfort and poor oral intake. Thoughtful use of over-the-counter topical agents, sialogogues, corticosteroids, and treatment interruptions can help improve tolerability of this adverse effect.

Neuropharmacology of Cevimeline and Muscarinic Drugs-Focus on Cognition and Neurodegeneration

At present, Alzheimer’s disease (AD) and related dementias cannot be cured. Therefore, scientists all over the world are trying to find a new approach to prolong an active life of patients with initial dementia. Both pharmacological and non-pharmacological pathways are investigated to improve the key symptom of the disease, memory loss. In this respect, influencing the neuromodulator acetylcholine via muscarinic receptors, such as cevimeline, might be one of the therapeutic alternatives. The purpose of this study is to explore the potential of cevimeline on the cognitive functions of AD patients. The methodology is based on a systematic literature review of available studies found in Web of Science, PubMed, Springer, and Scopus on the research topic. The findings indicate that cevimeline has shown an improvement in experimentally induced cognitive deficits in animal models. Furthermore, it has demonstrated to positively influence tau pathology and reduce the levels of amyloid-β (Aβ) peptide in the cerebral spinal fluid of Alzheimer’s patients. Although this drug has not been approved by the FDA for its use among AD patients and there is a lack of clinical studies confirming and extending this finding, cevimeline might represent a breakthrough in the treatment of AD.

From Oxiranes to Oligomers: Architectures of U.S. FDA Approved Pharmaceuticals Containing Oxygen Heterocycles

Oxygen heterocycles are the second most common type of heterocycles that appear as structural components of U.S. Food and Drug Administration (FDA) approved pharmaceuticals. Analysis of our database of drugs approved through 2017 reveals 311 distinct pharmaceuticals containing at least one oxygen heterocycle. Most prevalent among these are pyranoses, with furanoses, macrolactones, morpholines, and dioxolanes rounding off the top five. The main body of this Perspective is organized according to ring size, commencing with three- and four-membered rings and ending with macrocycles, polymers, and unusual oxygen-containing heterocycles. For each section, all oxygen heterocycle-containing drugs are presented along with a brief discussion about structural and drug application patterns.

Oral chronic graft-versus-host disease: report from the International Consensus Conference on clinical practice in cGVHD

Chronic graft-versus-host disease (cGVHD) is a multi-organ disease that occurs post-hematopoietic stem cell transplantation, with the mouth being one of the most frequently affected organs. In 2009, the German-Austrian-Swiss working party on bone marrow and blood stem cell transplantation held a consensus conference to define clinical management of cGVHD. The consensus conference aimed to summarize the literature on diagnosis and topical treatment options for oral cGVHD and to provide recommendations for clinical practice, including routine dental and oral care as well as monitoring for secondary malignancies and bisphophonate-induced osteonecrosis of the jaw.

Cevimeline

Cevimeline is an orally administered muscarinic receptor agonist that is indicated for the treatment of symptoms of dry mouth in patients with Sjogren's syndrome. Several well designed placebo-controlled trials demonstrated that 4-12 weeks' therapy with cevimeline 30 mg three times daily improved symptoms of dry mouth in patients with Sjogren's syndrome. Other symptoms, such as dry eye symptoms and overall dryness, also improved to a significantly greater extent with cevimeline than with placebo. Moreover, cevimeline significantly improved the salivary flow rate in patients with Sjogren's syndrome. Increased salivary flow was maintained in the longer term with cevimeline in patients with Sjogren's syndrome and symptoms of dry mouth, according to the results of an open-label 52-week study. From week 20 onwards, rates of patient and investigator satisfaction with the cevimeline dosage were > or =88%. Oral cevimeline 30 mg three times daily was generally well tolerated in patients with Sjogren's syndrome, with many of the most commonly reported adverse events reflecting the pharmacological action of the drug.

Effect of a muscarinic M3 receptor agonist on gastric motility

Muscarinic M3 receptors exist in the gastrointestinal wall in humans and the muscarinic M3 agonist cevimeline hydrochloride (Evoxac) is a candidate therapeutic agent for the treatment of xerostomia in Sjögren's syndrome. However, M3 receptor agonists are not known to show efficacy for diseases associated with abnormal gastrointestinal motility. Herein the effects are reported of cevimeline on gastric motility in two patients with non-ulcer dyspepsia. The patients both received long-term proton pump inhibitor therapy for 6 months, but their symptoms persisted. Then cevimeline was administered orally for 8 weeks at 30 mg three times daily (90 mg/day) and their dyspepsia symptoms improved. Electrogastrography was performed to examine gastric motility before and after administration of the M3 agonist. The fasting or nocturnal wave rate was significantly increased after administration compared with before administration, but no significant postprandial changes were seen. No adverse effects of cevimeline were observed. This drug might be a candidate therapeutic agent for non-ulcer dyspepsia. Because its postprandial effects on gastrointestinal motility are unclear, a dose-finding clinical study should be performed in the future.

Salivary dysfunction associated with systemic diseases: systematic review and clinical management recommendations

OBJECTIVES

The objective of this study was to identify systemic diseases associated with hyposalivation and xerostomia and develop evidence-based management recommendations for hyposalivation/xerostomia.

STUDY DESIGN

Literature searches covered the English language medical literature from 1966 to 2005. An evidence-based review process was applied to management studies published from 2002 to 2005.

RESULTS

Several systemic diseases were identified. From studies published 2002 to 2005, 15 were identified as high-quality studies and were used to support management recommendations: pilocarpine and cevimeline are recommended for treating hyposalivation and xerostomia in primary and secondary Sjögren's syndrome (SS). IFN-alpha lozenges may enhance saliva flow in primary SS patients. Anti-TNF-alpha agents, such as infliximab or etanercept, are not recommended to treat hyposalivation in SS. Dehydroepiandrosterone is not recommended to relieve hyposalivation or xerostomia in primary SS. There was not enough evidence to support any recommendations for the use of local stimulants, lubricants, and protectants for hyposalivation/xerostomia. However, professional judgment and patient preferences may support the use of a specific product for an individual patient.

CONCLUSIONS

These evidence-based management recommendations should guide the clinician's management decisions for patients with salivary dysfunction related to systemic disease. Future treatment strategies may include new formulations of existing drugs, e.g., local application of pilocarpine. Recent discoveries on gene expression and a better understanding of the etiopathogenesis of SS may open new treatment options in the future.

Effect of cevimeline on salivary components in patients with Sjögren syndrome

The aim of this study is to clarify the effects of cevimeline on various components in human saliva, such as immunoglobulin A (IgA), lysozyme, alpha-amylase and squamous cell carcinoma (SCC) antigen. Twelve female patients with Sjögren syndrome (SS) and 14 healthy women were enrolled. After the first saliva collection, one capsule (30 mg) of cevimeline was administered to each subject. Saliva was collected again after 90 min. The salivary flow rate and concentration of each component were measured. In both groups the salivary flow rate and amylase concentration were significantly increased by cevimeline. The lysozyme and IgA concentrations did not change significantly in both groups. The SCC antigen concentration did not change significantly in the SS group, but it decreased significantly in the control group. The secretion rates of amylase and IgA showed significant increases in both groups. The secretion rate of lysozyme significantly increased only in the control group, while the secretion rate of SCC significantly increased only in the SS group. Cevimeline augments not only the salivary flow rate but also the secretion rate of some digestive and/or defense factors from infections. It may be beneficial for SS patients to continue taking cevimeline to prevent oral infections, and other serious sequelae.

How can oral health care providers determine if patients have dry mouth?

BACKGROUND

Dentists recognize the importance of saliva in maintaining oral health and often are familiar with the clinical effects an insufficient salivary flow can have on oral tissues. A variety of medical conditions and medications can alter salivary secretion and composition. Typically, diagnosis of hyposalivation is made only after damage has occurred to the oral tissues.

OVERVIEW

The author describes a series of clinical steps that, if followed properly, may help in the early detection of salivary gland hypofunction and prevention of its severe complications. This four-step approach includes identifying a patient's chief complaint and the symptoms and duration of illness that brought the patient to the dentist, as well as any approaches the patient took to relieve symptoms; obtaining a medical history that includes a review of the body systems; performing a clinical evaluation that notes the patient's overall condition in addition to the health and functioning of the salivary glands and oral soft and hard tissues; and, when needed, conducting further diagnostic evaluations.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Oral health care providers will continue to face the challenges of treating new and recurrent carious lesions if the profession's approach to salivary hypofunction remains reactive rather than proactive. The recommendations in this article may enhance clinicians' awareness of the objective methods used to identify patients with salivary gland hypofunction or those at risk of developing it. It is hoped that early identification of asymptomatic patients at risk of developing hyposalivation, as well as symptomatic patients will lower the incidence and prevalence of dental caries and fungal infection in this population and ultimately enhance their quality of life.