Xylazine: A Drug Adulterant of Clinical Concern

PURPOSE OF REVIEW

The opioid epidemic has been responsible for significant morbidity and mortality in the USA and worldwide. As a result, it is essential to recognize the threat these potent drugs can cause when illicitly used. Specifically, introducing fentanyl as a drug adulterant has been shown to impact overdose rates drastically. In this regard, the Drug Enforcement Agency recently released a public safety alert announcing the new threat of a new adulterant called xylazine. Xylazine is a powerful animal sedative with a different mechanism of action when compared to illicit opioids such as heroin and fentanyl. Xylazine is typically injected intravenously via a syringe, often in combination with multiple other drugs. One of the most common drugs, xylazine, is taken in combination with fentanyl, with users of this drug combination describing xylazine as prolonging the euphoric sensation produced by fentanyl.

RECENT FINDINGS

Xylazine may cause adverse effects such as bradycardia, brief hypertension followed by hypotension, premature ventricular contractions, ataxia, slurred speech, sedation, and respiratory depression. Much of the recent literature on xylazine use in humans comes from case reports and review articles. Related to widespread use in veterinary medicine and increasing circulation in illicit drug markets, there is a critical need for public awareness and additional clinical-based studies to further increase understanding of mediated or modulated pharmacological effects of xylazine in humans. Further research is urgently needed to more clearly understand the implications of unregulated xylazine in the illicit drug market, to formulate public health interventions, and to implement harm reduction strategies.

The Effect of Cannabis Use on Depression

This article presents the case of a 21-year-old female with a psychiatric history of depression and a history of chronic cannabis use who presented to the emergency department after overdosing on ondansetron and was urine test positive for marijuana (tetrahydrocannabinol (THC)). The patient was later transferred to a psychiatric unit for further evaluation, and after six days of hospitalization and cessation of marijuana, the patient demonstrated gradual improvement in her mental status examination and was deemed fit for discharge with follow-up instructions. This case illustrates the effect of cannabis use and cannabis use disorder on those with major depressive disorder (MDD), the component of cannabis that worsens the symptoms of depression, the role of the endocannabinoid system (ECS) in depression, and available treatments.

Tianeptine, an Antidepressant with Opioid Agonist Effects: Pharmacology and Abuse Potential, a Narrative Review

Tianeptine is an antidepressant drug approved for the treatment of major depressive disorder in countries other than the US. It is classified as an atypical tricyclic antidepressant and has shown potential benefits in addressing anxiety and irritable bowel disease. However, it is important to note that tianeptine is not approved for any use by the United States Federal Drug Administration (FDA). Despite its lack of approval by the FDA, tianeptine has been distributed online and at small retail locations. The term "gas station drugs" refers to a wide range of substances typically available for purchase from gas stations, corner stores, bodegas, mini marts, smoke shops, and the Internet. These substances may be produced commercially by drug manufacturers or in clandestine laboratories to mimic the effects of more well-known illicit/controlled substances such as marijuana, cocaine, opioids, etc. Tianeptine has made its way to convenience stores and gas station shelves, branded as "Zaza" and "Tianna Red." It can also be obtained online from independent vendors without a prescription. Misuse of tianeptine can lead to euphoric, opioid-like highs with the potential for chronic users to develop dependence and tolerance. Overdose and use in suicide attempts have also been documented. This manuscript is a narrative review, highlighting the dangers of tianeptine and other gas station drugs and underscoring the urgent need to regulate these substances.

The Use of Oxytocin for the Treatment of Opioid Use Disorder

Nearly 27 million people have an opioid use disorder (OUD) according to the 2016 Global Burden of Disease study, most of which occur in the US where opioids are a common class of medication used to treat acute and chronic pain. In 2016 alone, more than 60 million patients had at least one prescription for opioids filled or refilled. Over the past decade, prescription rates have risen astronomically and have created an epidemic in the US dubbed the "opioid crisis." In this regard, there has been an increase in overdoses and OUD diagnoses. Several studies have found dysregulation of balance between several neurotransmitters involved in the neural circuitry that subserves several behavioral domains, such as reward recognition, motivation, learning, and memory, affect, stress, and executive function, that contribute to the manifestation of craving. On the horizon is a new treatment approach consisting of the neuropeptide oxytocin, which may be involved in the overlapping mechanisms of stable attachment formation and coping with stress. Through this mechanism, it can shift processing from novelty and reward-seeking to an appreciation of familiarity and thus reduce stress and increase resilience in the face of addiction. It has been hypothesized that there is a connection between the glutaminergic and oxytocinergic systems, making oxytocin a possible therapeutic agent in reducing drug-induced actions seen in OUD patients. This manuscript will review the potential and feasible use of oxytocin in treating OUD.

Ketamine Evolving Clinical Roles and Potential Effects with Cognitive, Motor and Driving Ability

While driving under the influence of drugs, drivers are more likely to be involved in and cause more accidents than drivers who do not drive under the influence. Ketamine is derived from phencyclidine and acts as a noncompetitive antagonist and allosteric modulator of N-methyl-D-aspartate receptors. Ketamine has been used to treat a variety of psychiatric disorders, with the most notable being treatment-resistant depression. With the rise of at-home ketamine treatment companies, the safety of unsupervised administration remains under evaluation. A study with ketamine and a ketamine-like medication, rapasitnel, showed that those who were given ketamine experienced more sleepiness and had decreased self-reported motivation and confidence in their driving abilities. Moreover, there seem to be significant differences in the acute versus persistent effects of ketamine, as well as the anesthetic versus subanesthetic doses, both in terms of effects and outcomes. These divergent effects complicate the clinical uses of ketamine, specifically involving driving, drowsiness, and cognitive abilities. This review aims to describe not only the various clinical uses of ketamine but also the potentially detrimental effects of driving under the influence, which should be understood to help with counseling the patients who use these substances, both for their well-being and to protect public safety.

Catalytic Reaction Model of Suicide

Suicide is a devastating outcome of unresolved issues that affect mental health, general wellbeing and socioeconomic stress. The biology of suicidal behavior is still poorly understood, although progress has been made. Suicidal behavior runs in families and genetic studies have provided initial glimpses into potential genes that contribute to suicide risk. Here, we attempt to unify the biology and behavioral dimensions into a model that can guide research in this area. The proposed model envisions suicidal behavior as a catalytic reaction that may result in suicide depending on the conditions, analogously to enzyme catalysis of chemical reactions. A wide array of substrates or reactants, such as hopelessness, depression, debilitating illnesses and diminished motivation can mobilize suicidal thoughts and behaviors (STBs), which can then catalyze the final step/act of suicide. Here, we focus on three biological substrates in particular: threat assessment, motivation to engage in life and impulsivity. Genetic risk factors can affect each of these processes and tilt the balance toward suicidal behavior when existential crises (real or perceived) emerge such as loss of a loved one, sudden changes in social status or serious health issues. Although suicide is a uniquely human behavior, many of the fundamental biological processes are evolutionarily conserved. Insights from animal models may help to shape our understanding of suicidal behavior in man. By examining counterparts of the major biological processes in other organisms, new ideas about the role of genetic risk factors may emerge along with possible therapeutic interventions or preventive measures.

Analysis of Major Depression Risk Genes Reveals Evolutionary Conservation, Shared Phenotypes, and Extensive Genetic Interactions

Major depressive disorder (MDD) affects around 15% of the population at some stage in their lifetime. It can be gravely disabling and it is associated with increased risk of suicide. Genetics play an important role; however, there are additional environmental contributions to the pathogenesis. A number of possible risk genes that increase liability for developing symptoms of MDD have been identified in genome-wide association studies (GWAS). The goal of this study was to characterize the MDD risk genes with respect to the degree of evolutionary conservation in simpler model organisms such as Caenorhabditis elegans and zebrafish, the phenotypes associated with variation in these genes and the extent of network connectivity. The MDD risk genes showed higher conservation in C. elegans and zebrafish than genome-to-genome comparisons. In addition, there were recurring themes among the phenotypes associated with variation of these risk genes in C. elegans. The phenotype analysis revealed enrichment for essential genes with pleiotropic effects. Moreover, the MDD risk genes participated in more interactions with each other than did randomly-selected genes from similar-sized gene sets. Syntenic blocks of risk genes with common functional activities were also identified. By characterizing evolutionarily-conserved counterparts to the MDD risk genes, we have gained new insights into pathogenetic processes relevant to the emergence of depressive symptoms in man.

Oxamniquine cures Schistosoma mansoni infection in a focus in which cure rates with praziquantel are unusually low

An outbreak of Schistosoma mansoni in northern Senegal was observed in 1988, and chemotherapy with praziquantel in this recently established focus resulted in very low parasitologic cure rates. Among other explanations, the emergence of a praziquantel-tolerant parasite strain was feared. To study this hypothesis further, 138 persons with endemic S. mansoni infection were randomly allocated to treatment with either 20 mg/kg oxamniquine or 40 mg/kg praziquantel. Parasitologic cure rates at 6 weeks were significantly higher in the oxamniquine group (79%) compared with those in the praziquantel group (36%; P = .0043). The reduction in egg counts was generally good, but 12% less reduced in the praziquantel group. These results confirm that cure rates with praziquantel were abnormally low, whereas oxamniquine performed satisfactorily, as in other areas in which S. mansoni is endemic. The possibility of a praziquantel-tolerant S. mansoni strain must therefore be studied carefully.

A comparison of medroxyprogesterone serum concentrations by the oral or intramuscular route in patients with persistent or recurrent endometrial carcinoma

A randomized study, comparing serum medroxyprogesterone concentrations by the oral and intramuscular routes, was performed on 22 patients with persistent or recurrent endometrial adenocarcinoma by six institutions of the Gynecologic Oncology Group. The oral group (11 patients) received cutaneous Provera (medroxyprogesterone), 50 mg three times a day, and the intramuscular group (11 patients) received 300 mg of Depo-Provera (medroxyprogesterone) weekly for at least 2 months. Serum levels were evaluated at 0, 2, 4, 6, 8, 10, and 12 hours after administration and every day for the first week and weekly thereafter for 8 weeks. The mean serum levels (nanograms per milliliter) of medroxyprogesterone in the oral group were consistently higher than the corresponding mean levels of the intramuscular group. In addition, from the first through eighth weeks, the measurements (medians) for the oral group were statistically higher than those for the intramuscular group. Although the study indicates a significant increase in serum levels achieved by the oral route, the follow-up period of patients under study is too early to evaluate its clinical effectiveness as compared to the intramuscular route.

Surgical treatment of stages IB and IIA invasive carcinoma of the cervix by radical abdominal hysterectomy

From 1963 to 1977, 349 radical abdominal hysterectomies with bilateral pelvic lymphadenectomy were performed for Stage IB (331 patients) and Stage IIA (18 patients) cervical cancer at the New York Medical College, with no operative deaths. Definitive diagnosis was obtained from the biopsy specimen in 281 patients. Twenty-nine patients were pregnant when the diagnosis was established. The average operating time was 4 hours and 48 minutes with an average blood loss of 900 ml. Eleven fistulas were noted: ureterovaginal, 7; vesicovaginal, 3; rectovaginal, 1. Since 1972, there have been no fistulas in 130 radical hysterectomies. Metastatic carcinoma of the regional lymph nodes was discovered in 27 patients for an incidence of 7.7%. Postoperative total pelvic external irradiation was utilized in 40 patients (27 with positive nodes, 10 with microscopic carcinoma in vascular channels, and an additional three patients with an inadequate vaginal extirpation margin). A total of 62% of those patients with poor prognostic criteria receiving postoperative irradiation are alive and well. Two hundred nineteen patients have been followed up for at least 5 years and the survival rate was 90%. Our data support the view that radical abdominal hysterectomy with bilateral pelvic lymphadenectomy is the treatment of choice for patients with Stages IB and IIA cervical cancer in the nonpregnant state, unless there are major medical contraindications.

Metastasis to the vagina from carcinoma of the breast

Carcinoma of the breast, metastatic to the ovary, is encountered frequently. The potential routes of dissemination include transcoelomic spread, lymphatic spread and vascular (arterial or venous) transportation. A case report of vaginal metastasis secondary to bilateral breast carcinoma is cited and the potential mechanisms for dissemination described.

Androstenedione metabolism in patients with endometrial cancer

The plasma concentration of androstenedione and the instantaneous conversion of androstenedione to estrone was increased in patients with endometrial cancer as compared to postmenopausal control subjects. Moreover, the per cent of estrone derived from androstenedione was increased in the cancer group.