Current Drug Targets - Volume 19, Issue 12, 2018

Sexual dysfunctions are commonly seen in women on selective serotonin reuptake inhibitors (SSRIs). The complexities of female sexual functioning are reflected through modulation of inter- playing factors like the neuropsychophysiological factors, inter-personal and relationship issue, psychiatric co-morbidities and physical disorder. The incidence of SSRIs-induced FSD is difficult to estimate because of the potential confounding effects of SSRIs, presence of polypharmacy, marital effect, socio-cultural factors and due to the design and assessment problems in majority of the studies. The exact mechanism of FSD-induced SSRIs is unknown. It has been postulated that although SSRIs may modulate other neurotransmitter system such as nitric oxide (NO), noradrenergic and dopamine in inducing FSD. In the present review, we highlight current evidence regarding potential mechanism of SSRIs in causing FSD, which include low sexual desire (low libido), arousal difficulties (lack of lubrication), and anorgasmia. The specific association of FSD to SSRI use, has not been ellucidated. The relationship is dose-dependent, and may vary among the groups with respect to mechanism of serotonin and dopamine reuptake, induction of release of prolactin from the pituitary gland, anticholinergic side-effects, inhibition of NO synthesis and emotional-memory circuit encryption for sexual experiences. Various interventional strategies exist regarding the treatment of SSRI-induced FSD and this includes tolerance, titration dosage, substitution to another antidepressant drug and psychotherapy. There is a need of better understanding of SSRIs-induced FSD for better treatment outcome.

Mitragyna speciosa is a tropical plant with narcotic effects. The antinociceptive effects of its crude extracts, bioactive compounds and structurally modified derivatives have been examined in rodent models. This review aims to summarize the evidence on the antinociceptive effects of M. speciosa and its derivatives and explore whether they can offer an alternative to morphine in pain management. Methanolic and alkaloid extracts of M. speciosa were shown to attenuate the nociceptive response in rodents. Mitragynine and 7-hydroxymitragynine offered better antinociceptive effects than crude extracts. Structurally modified derivatives of 7-hydroxymitragynine, such as MGM-9, MGM- 15, MGM-16, demonstrated superior antinociceptive effects compared to morphine. M. speciosa and its derivatives mainly act on the opioid receptor, but receptor subtypes specificity differs between each compound. The tolerance and adverse side effects of M. speciosa and its derivatives are similar with morphine. The affinity of MGM-9 on kappa-opioid receptor could potentially limit the effects of drug dependence. In conclusion, M speciosa derivatives can offer alternatives to morphine in controlling chronic pain. Structural modification of mitragynine and 7-hydroxymitragynine can generate compounds with higher potency and lesser side-effects. Human clinical trials are required to validate the use of these compounds in clinical setting.

Erectile function (EF) is a prerequisite for satisfactory sexual intercourse (SI) and central to male sexual functioning. Satisfactory SI eventually initiates orgasm – a biopsychophysiological state of euphoria – leading to a sense of bliss, enjoyment and positive mental well being. For a psychiatrist, treating ED is self-propelled to harmonize these pleasurable experiences alongside with encouragement of physical wellness and sensuality. Hence, the role of PDE-5i is pivotal in this context and constitutes a therapeutic challenge. PDE-5i work via the dopaminergic-oxytocin-nitric oxide pathway by increasing the availability of endothelial's guanosine monophosphate (GMP), immediately causing relaxation of the penile smooth muscle and an erection. The PDE-5i, like sildenafil, vardenafil and tadalafil, are effective in the treatment of ED with some benefits/ flexibilities and disadvantages compared to other treatment modalities. Prescribed PDE-5i exclusively improve EF, fostering male's self-confidence and self-esteem. Treatment failures are associated with factors such as absent (or insufficient) sexual stimulation, psychosexual conflicts and the co-existence of medical disorders. Managing ED requires dealing with underlying medical diseases, addressing other co-morbid sexual dysfunctions like premature ejaculation (PE), and educating the patient on healthy life-styles. Furthermore, by dealing with interpersonal dynamics within the couple and embracing adequate lifestyles (managing stress and revising one's sexual scripts), PDE-5i treatment benefits may be enhanced. In this review, we propose a holistic conceptual framework approach for psychiatric management of patients with ED.

In the past two decades, the search for novel pharmacotherapies to treat alcohol addiction has been a global endeavor. This has resulted in several drugs that have been approved and successfully marketed for public use while some are still in the testing phase. These pharmacological agents, though effective for the treatment of alcoholism, are not without shortcomings; such as abuse potential, serious mental and physical adverse effects, interaction with alcohol and also poor metabolism and excretion. As more is being understood about the neurobiology of alcohol addiction as well as the unique pharmacological action of these drugs, new agents are evaluated for potential benefits when used as an adjunct in combination therapy. This review article summarizes the novel pharmacotherapeutic approaches used in the treatment of alcohol addiction by focusing on the drugs, which include neramexane, gabapentin, baclofen, aripiprazole, nalmafene, and quetiapine.

Hypersexuality refers to abnormally increased or extreme involvement in any sexual activity. It is clinically challenging, presents trans-diagnostically and there is extensive medical literature addressing the nosology, pathogenesis and neuropsychiatric aspects in this clinical syndrome. Classification includes deviant behaviours, diagnosable entities related to impulsivity, and obsessional phenomena. Some clinicians view an increase in sexual desire as ‘normal’ i.e. psychodynamic theorists consider it as egodefensive at times alleviating unconscious anxiety rooted in intrapsychic conflicts. We highlight hypersexuality as multi-dimensional involving an increase in sexual activity that is associated with distress and functional impairment. The aetiology of hypersexuality is multi-factorial with differential diagnoses that include major psychiatric disorders (e.g. bipolar disorder), adverse effects of treatments (e.g. levodopatreatment), substance-induced disorders (e.g. amphetamine substance use), neuropathological disorders (e.g. frontal lobe syndrome), among others. Numerous neurotransmitters are implicated in its pathogenesis, with dopamine and noradrenaline playing a crucial role in the neural reward pathways and emotionally- regulated limbic system neural circuits. The management of hypersexuality is determined by the principle of de causa effectu evanescent, if the causes are treated, the effect may disappear. We aim to review the role of pharmacological agents causing hypersexuality and centrally acting agents treating the associated underlying medical conditions. Bio-psycho-social determinants are pivotal in embracing the understanding and guiding management of this complex and multi-determined clinical syndrome.

Sexuality is an important dimension in human beings as a form of expression of individuality. For many decades, sexual functioning has been a neglected area among patients suffering from schizophrenia. It was a presumption that patients with schizophrenia could be asexual and this could be secondary to overwhelming situations of delusion, hallucination, hostility and negative symptoms among others. The deficient in sexual functioning are due to innate factors, i.e. negative symptoms (apathy, avolition and amotivation) and also as a result of prefrontal dysfunction, i.e. inability to plan and execute meaningful relationship. Adverse effects of the psychopharmacological agents, especially the typical antipsychotics, e.g. dystonia, excessive sedation and hyperprolactinemia may interfere with patients' sexual activity. In this review, we highlight the neurobiology of schizophrenia in the context of understanding sexual functioning and to integrate the knowledge of dopamine-serotonin neurotransmitter's interaction and the receptors' target. Interventional approaches consist of psychopharmacological and psychosocial interventions. In the perspective of sexuality, we recommend atypical antipsychotic should be placed as the first line treatment for both drug naïve patients and also to patients who are already receiving psychopharmacological agents in consideration for a drug-switch from typical to atypical antipsychotics. Aripiprazole, clozapine, olanzapine and quetiapine exert benefits in terms of sexual functioning recovery due to their atypical mechanism of action. However, the potential adverse effect like metabolic syndrome should be adequately managed to prevent negative consequences. Psychosocial interventions, i.e. psychoeducation, destigmatization, supportive psychotherapy and psychiatric rehabilitation also play a crucial role in the management. In conclusion, restoration of sexual function is an achievable recovery target in patients with schizophrenia through these biopsycho- social interventions.

Background: Vortioxetine is a multimodal antidepressant that has been developed for the treatment of major depressive and anxiety disorders. The aim of this review is to quantitatively synthesize all data of the efficacy, safety and tolerability of Vortioxetine in treating anxiety disorder. Method: Terms of “Vortioxetine” OR “LuAA21004” AND “anxiety” OR “fear” OR “panic” OR “phobia” were searched. A total of two phase II and five phase III clinical trials were found. Results: Vortioxetine was overall superior to placebo in terms of the mean change from baseline in HAM-A total score at week 8 with the pool effect size of -2.95, 95% CIs, -4.37 to -1.53, p<0.01. The patients who received 5 mg of Vortioxetine had higher response rate when compared to placebo (pooled odds ratio=1.4, 95% CI = 1.08 to 1.82, p=0.01). However, the pooled odds ratio of the HAMA remission rate was not statistically significant for both Vortioxetine and placebo (pooled odds ratio= 1.06, 95% CI = 0.86 to 1.30, p=0.62). Although the discontinuation due to adverse effects was higher in Vortioxetine than placebo group (pooled OR= 1.55, 95% CI = 1.04 to 2.31, P= 0.037), the lack of efficacy (pooled OR= 0.39, 95% CI = 0.27 to 0.57, P<0.01) was higher in placebo than Vortioxetine group. Most of the adverse effects were mild and moderate. Overall, Vortioxetine displayed a good safety and tolerability profile. Conclusion: This review supports the use of Vortioxetine for anxiety disorder. However, further longterm placebo-control observational study or a post market survey would help in strengthening the evidence for this treatment modality.

Nicotine is one of the most abused substances worldwide and can cause several harmful effects on health. One of the harmful effects, which is often ignored, is osteoporosis. Smoking has been shown to cause a decrease in bone mineral density in humans. Animal studies have proven that nicotine exerts negative effects on bone. The number of people who smoke increases each day. Those who smoke start at a very young age and they usually smoke for years. This will increase the risk of developing osteoporosis. As the prevalence of osteoporosis increases, the risk of fractures also increases. The major concerns are disability following fractures, mortality due to complications after fractures and the increasing cost of management and therapy. This paper will review the effects of nicotine on bone and the potential natural products which can be used as treatment for nicotine-induced osteoporosis.

Cancer patients are commonly associated with various physical and psychological symptoms. In palliative setting, the aims are to relieve those symptoms, improve quality of life, and increase medication adherence among cancer patients. Antidepressants are generally accepted for the treatment of depression among patients with or without cancer. Some other potential benefits of the antidepressants have been reported in cancer patients. Objective: This study aims to review the use of antidepressants for physical and psychological symptoms in cancer patients. Results: Our findings showed the mixed result of positive and negative findings in various symptoms associated with cancer patients. These studies are categorised according to the hierarchy of evidence from high to low level, namely randomised controlled trials, cohort studies, case-control studies, case series, case reports, as well as other type of publications. The majority of antidepressants used in cancer patients seem to be beneficial for the treatment of depression, anxiety, hot flashes and other symptoms such as sexual dysfunction, fatigue, nicotine dependence, vasomotor symptoms, executive functions, sleep problems, pruritus, as well as for hypochondriasis. While fluoxetine was found to be associated with the reduction of antiemetic property in ondansetron, mirtazapine was identified to be a good alternative in treating nausea and cachexia among cancer patients. Conclusion: More research studies with adequate statistical power are warranted to validate the use of antidepressants among cancer patients in treating these physical and psychological symptoms.

Background: Scientific reports had shown that stress is related to numerous pathological changes in the body. These pathological changes can bring about numerous diseases and can significantly cause negative effects in an individual. These include gastric ulcer, liver pathology and neurobehavioral changes. A common pathogenesis in many diseases related to stress involves oxidative damage. Therefore, the administration of antioxidants such as vitamin E is a reasonable therapeutic approach. However, there is conflicting evidence about antioxidant supplementation. Objective: The aim of this work was to summarize documented reports on the effects of tocopherol and tocotrienol on various pathological changes induced by stress. Results and Conclusion: This review will reveal the scientific evidence of enteral supplementation of vitamin E in the forms of tocotrienol and tocopherol in animal models of stress. These models mimic the stress endured by critically ill patients in a clinical setting and psychological stress in individuals. Positive outcomes from enteral feeding of vitamin E in reducing the occurrence of stress-induced pathological changes are discussed in this review. These positive findings include their ability to reduced stress-induced gastric ulcers, elevated liver enzymes and improved locomotors activity. Evidences showing tocotrienol and tocopherol effects are not just related to its ability to reduce oxidative stress but also acting on other mechanism, are discussed.