Gabapentin for the treatment of hot flashes in women with natural or tamoxifen-induced menopause: A systematic review and meta-analysis

Evaluation and Comparison of Citalopram and Venlafaxine for Management of Hot Flashes in Women with Breast Cancer

BACKGROUND

Breast cancer is the most common cancer in women worldwide. Premature menopause and hot flashes are the main complications of breast cancer treatments. About 40 to 50 percent of breast cancer women who undergo chemotherapy are experiencing premature menopause symptoms, including hot flashes. Some endocrine therapies such as tamoxifen and aromatase inhibitors are associated with induction or aggravating hot flashes. Hot flashes are often debilitating and significantly impair daily functions. Therefore many therapeutic options have been studied so far for the management of this adverse effect. However, there are still some clinical challenges in managing hot flashes in patients with breast cancer.

OBJECTIVE

We aimed to evaluate and compare the efficacy of venlafaxine and citalopram on hot flashes in breast cancer women receiving tamoxifen.

DESIGN

We conducted a double-blind, placebo-controlled trial in forty-one, 35 to 65 years old female patients. The study lasted for four weeks, and the follow-up was for two months. Venlafaxine and citalopram treatments started with doses of 37.5 mg or 10 mg, respectively. Venlafaxine and citalopram dosages were increased in the second week to 75 and 20 mg, respectively. The study was conducted during the year 2017.

KEY RESULTS

The results indicated that the total efficacy was significantly different in groups receiving citalopram, venlafaxine, and placebo. Total efficacy in the placebo group, venlafaxine, and citalopram was 14.3, 53.8, and 64.3%, respectively (p=0.02). During the second week, the efficacy in groups receiving citalopram, venlafaxine, and placebo was 57.1, 53.8, and 14.3%, respectively (p=0.04). Generally, both citalopram and venlafaxine were well tolerated. The associated adverse effects were mild to moderate in both groups.

CONCLUSIONS

Although citalopram was associated with more adverse effects, including constipation, it was more effective in reducing the frequency of hot flashes when compared to venlafaxine or placebo.

Hormone Therapy in Menopause: Concepts, Controversies, and Approach to Treatment

Hormone therapy (HT) is an effective treatment for menopausal symptoms, including vasomotor symptoms and genitourinary syndrome of menopause. Randomized trials also demonstrate positive effects on bone health, and age-stratified analyses indicate more favorable effects on coronary heart disease and all-cause mortality in younger women (close proximity to menopause) than in women more than a decade past menopause. In the absence of contraindications or other major comorbidities, recently menopausal women with moderate or severe symptoms are appropriate candidates for HT. The Women's Health Initiative (WHI) hormone therapy trials-estrogen and progestin trial and the estrogen-alone trial-clarified the benefits and risks of HT, including how the results differed by age. A key lesson from the WHI trials, which was unfortunately lost in the posttrial cacophony, was that the risk:benefit ratio and safety profile of HT differed markedly by clinical characteristics of the participants, especially age, time since menopause, and comorbidity status. In the present review of the WHI and other recent HT trials, we aim to provide readers with an improved understanding of the importance of the timing of HT initiation, type and route of administration, and of patient-specific considerations that should be weighed when prescribing HT.

[Non-hormonal alternatives for the management of menopausal hot flushes. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

One of the major symptoms of climacteric syndrome is hot flushes (HF). They are most often experienced as very disabling. Estrogen therapy is the most effective treatment. However, it may be contraindicated in some women. The aim of this article is to provide a review of the scientific literature on pharmacological and non-pharmacological alternatives in this context. Only randomized trials and meta-analyses of randomized trials were considered. This review shows that some treatments usually used in non-gynecological or endocrinological disease have significant effect in reducing the frequency and/or severity of HF. Hence, some selective serotonin reuptake inhibitors (paroxetine, citalopram and escitalopram), serotonin and norepinephrine reuptake inhibitors (venlafaxine, desvenlafaxine) gabapentin, pregabalin and clonidine have a statistically effect as compared with placebo in reducing, the frequency and/or severity of HF. Some phytoestrogens, such as genistein, may also reduce the frequency of HF. Regarding non-pharmacological interventions, hypnosis, acupuncture or yoga have been analyzed with significant beneficial results, even if their evaluation is difficult by the absence of a good placebo group in most trials. By contrast, other approaches, both pharmacological or non-pharmacological, appear to be ineffective in the management of HT. These include homeopathy, vitamin E, alanine, omega 3, numerous phytoestrogens (red clover, black cohosh…), primrose oil, physical activity. In women suffering from breast cancer, several additional problems are added. On the one hand because all phytoestrogens are contraindicated and on the other hand, in patients using tamoxifen, because the molecules, that interact with CYP2D6, are to be formally avoided because of potential interaction with this anti-estrogen treatment. In conclusion, several pharmacological and non-pharmacological alternatives have significant efficacy in the management of severe HF.

Optimizing care for younger women with hormone receptor-positive, HER2-negative metastatic breast cancer

Treatment strategies for hormone receptor-positive (HR⁺ ), human epidermal growth factor receptor 2-negative (HER2^- ) metastatic breast cancer in young women (<40 years at diagnosis) have traditionally been extrapolated from data obtained from trials conducted either exclusively or predominantly in the postmenopausal setting. These young patients are usually treated with ovarian function suppression (OFS) + endocrine therapy (ET) ± targeted therapy, except if there is a concern about endocrine resistance or a need to gain rapid disease control due to the onset of visceral crisis. This review examines evidence that supports the use of a cyclin-dependent kinase 4/6 inhibitor, in combination with OFS and ET, when treating premenopausal or perimenopausal women with HR⁺ /HER2^- metastatic breast cancer. This includes data from the MONALEESA-7 study (treating only premenopausal/perimenopausal women in the first-line setting), and the results of subgroup analyses from the PALOMA-3 and MONARCH-2 trials. We also consider a number of age-specific challenges that younger breast cancer patients can face, highlighting the importance of a multidisciplinary approach to ongoing care.

Efficacy and safety of gabapentin and pregabalin in patients with vasomotor symptoms: a systematic review and meta-analysis

OBJECTIVE

Vasomotor symptoms are common among postmenopausal women and patients receiving hormone deprivation therapies, and emerging studies are exploring gabapentin's and pregabalin's effects as nonhormonal treatment options. We aimed to assess the efficacy and safety of these 2 drugs.

DATA SOURCES

Based on a preregistered protocol (Prospective Register of Systematic Reviews -CRD42019133650), we searched 10 databases (PubMed, Embase, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Chinese Biological Medical Literature, Chinese National Knowledge Infrastructure, Chinese Journals Full-text Database [VIP], and Wanfang) as well as the World Health Organization international clinical trials registry platform and reference lists of related literatures.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials and randomized crossover studies exploring gabapentin and pregabalin among women patients with vasomotor symptoms were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement was followed. Two reviewers independently selected studies, assessed bias, and extracted data. Mean difference and standardized mean difference with 95% confidence intervals were assessed by random-effects models. Heterogeneities were assessed by I² statistics, and the quality of evidence was evaluated by the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Nineteen randomized controlled trials and 2 randomized crossover trials reporting results from 3519 participants were included. Gabapentin could reduce hot flash frequency (mean difference, -1.62, 95% confidence interval, -1.98 to -1.26 after 4 weeks; mean difference, -2.77, 95% confidence interval, -4.29 to -1.24 after 12 weeks) and composite score (standardized mean difference, -0.47, 95% confidence interval, -0.71 to -0.23 after 4 weeks; standardized mean difference, -0.77, 95% confidence interval, -1.15 to -0.40 after 12 weeks) compared with placebo. Both menopausal participants and patients with breast cancer benefited from treatment. Higher risks of dizziness and somnolence were found in the gabapentin group than in the control group (risk ratio, 4.45, 95% confidence interval, 2.50-7.94; risk ratio, 3.29, 95% confidence interval, 1.97-5.48, respectively). Estrogen was more effective in reducing hot flash frequency than gabapentin. No statistically significant difference in reduction of hot flash severity score was found between gabapentin and antidepressants. The trials comparing gabapentin or pregabalin with the other interventions were too limited to make a conclusion.

CONCLUSION

Favorable effects of gabapentin in relieving vasomotor symptoms were observed, compared with controls, but were less effective than those of estrogen. Evidence supporting the therapeutic effect of pregabalin is still lacking.

Gabapentin for the treatment of hot flushes in menopause: a meta-analysis

OBJECTIVE

Gabapentin is used to treat vasomotor symptoms (VMS) in postmenopausal women with contraindications to hormonal therapy or who prefer alternatives. We investigated the efficacy and tolerability of gabapentin for treating menopausal hot flushes via a meta-analysis.

METHODS

We searched the PubMed, MEDLINE, EMBASE, and CENTRAL databases for English-language articles published until June, 2018. The following search terms were used: "menopause," "hot flushes," "vasomotor symptoms," "gabapentin," and "non-hormonal therapy." Primary outcomes were frequency, duration, and composite score of hot flushes. Secondary outcomes were adverse effects and dropout rate. We estimated the standardized mean difference (SMD) and combined odds ratio (OR) using fixed or random-effects models, depending on study heterogeneity. Subgroup and meta-regression analyses of gabapentin dosage were performed.

RESULTS

We included seven randomized controlled trials that compared single-agent gabapentin with placebo for treating hot flushes in the meta-analysis. Women who received gabapentin reported a significantly greater reduction in the frequency (SMD 2.99 [95% confidence interval 2.01-3.98], P < 0.001), duration (0.89 [0.49-1.30], P < 0.001), and composite score (2.31 [1.50-3.11], P < 0.001) of hot flushes. Adverse events were significantly more frequent among those taking gabapentin than among those taking the placebo (OR 1.58 [0.98-2.18], P < 0.001; and 1.19 [0.43-1.95], P = 0.002 for dizziness and unsteadiness, respectively).

CONCLUSIONS

Gabapentin could be used to treat VMS in postmenopausal women with contraindications to hormonal therapy. Future studies should investigate the lowest effective dose of gabapentin to minimize adverse effects. : Video Summary:http://links.lww.com/MENO/A521.

Comparative effectiveness of electro-acupuncture versus gabapentin for sleep disturbances in breast cancer survivors with hot flashes: a randomized trial

OBJECTIVE

Sleep disturbance is a major consequence of hot flashes among breast cancer survivors. This study evaluated the effects of electro-acupuncture (EA) versus gabapentin (GP) for sleep disturbances among breast cancer survivors experiencing daily hot flashes.

METHODS

We analyzed data from a randomized controlled trial involving 58 breast cancer survivors experiencing bothersome hot flashes at least two times per day. Participants were randomly assigned to receive 8 weeks of EA or daily GP (total dose of 900 mg/d). The primary outcome was change in the total Pittsburgh Sleep Quality Index (PSQI) score between groups at week 8. Secondary outcomes include specific PSQI domains.

RESULTS

By the end of treatment at week 8, the mean reduction in PSQI total score was significantly greater in the EA group than the GP group (-2.6 vs -0.8, P = 0.044). The EA also had improved sleep latency (-0.5 vs 0.1, P = 0.041) and sleep efficiency (-0.6 vs 0.0, P = 0.05) compared with the GP group. By week 8, the EA group had improved sleep duration, less sleep disturbance, shorter sleep latency, decreased daytime dysfunction, improved sleep efficiency, and better sleep quality (P < 0.05 for all) compared with baseline, whereas the GP group improved in duration and sleep quality only (P < 0.05).

CONCLUSIONS

Among women experiencing hot flashes, the effects of EA are comparable with GP for improving sleep quality, specifically in the areas of sleep latency and efficiency. Larger randomized controlled trials with longer follow-ups are needed to confirm this preliminary finding.

Alpha2delta ligands, gabapentin, pregabalin and mirogabalin: a review of their clinical pharmacology and therapeutic use

INTRODUCTION

The first two alpha₂delta ligands - gabapentin (GBP) and pregabalin (PGB) - were initially synthesized as antiepileptics; however, they were later also found to be useful for the treatment of additional conditions. Areas covered: Relevant publications describing potential underlying mechanisms, clinical pharmacokinetics/pharmacokinetics, and clinical efficacy and safety of these drugs in various disease conditions were searched in PubMed and Scopus and included in this review. Expert commentary: GBP and PGB are effective for the treatment neuropathic pain, fibromyalgia and epilepsy; in addition, they may be useful for the reduction of postoperative pain. PGB is also effective for the treatment of generalized anxiety disorder and GBP for the treatment of restless legs syndrome. GBP may be considered a treatment option for pain associated with Guillain-Barré Syndrome and phantom limb and for the management of uremic pruritus. Mirogabalin (MGB), recently developed, is being investigated for the treatment of peripheral neuropathic pain and fibromyalgia, showing promising results in patients with diabetic peripheral neuropathy. Their most frequent adverse reactions are of neuropsychiatric nature and include fatigue, dizziness, sedation, somnolence, and ataxia; peripheral edema and weight gain are also frequently described. Pharmacokinetic interactions are scarce; however, pharmacodynamic interactions have been described in association with drugs with CNS-depressant effects.

ENDOCRINE DILEMMA: Managing menopausal symptoms after breast cancer

Managing the symptoms of menopause after a diagnosis of breast cancer offers some unique clinical challenges. For some women, vasomotor symptoms can be severe and debilitating, and hormone therapy is at least relatively contraindicated. Non-oestrogen therapies for hot flushes include SSRIs, clonidine, gabapentin and perhaps black cohosh extracts. Vulvovaginal atrophy can usually be alleviated by simple moisturizers, although some may need specialized physiotherapy such as vaginal dilators. In a small number, topical oestrogens may be the only treatment that works. The CO2 laser may be a novel, non-oestrogen therapy to alleviate this unpleasant symptom. Bone loss can be accelerated in some patients on AIs or those who had early menopause induced by chemotherapy.

Tomato juice intake increases resting energy expenditure and improves hypertriglyceridemia in middle-aged women: an open-label, single-arm study

Background

Tomato-based food products have health-promoting and disease-preventing effects. Some tomato juice ingredients may have health benefits for middle-aged women, including women with menopausal symptoms and cardiovascular diseases. We investigated the net effect of tomato juice intake on several health parameters in women in this age group.

Methods

An open-label, single-arm study was conducted, involving 95 women (40-60-years-old) who had at least one menopausal symptom. The participants refrained from foods and drinks rich in tomato and tomato-based products for 2 weeks prior to the study and during the 8 weeks of tomato juice consumption. After the run-in period, the women were asked to consume 200 mL of unsalted tomato juice, twice daily for 8 weeks. Their menopausal symptoms were evaluated using the Menopausal Symptom Scale (MSS), Hospital Anxiety and Depression Scale (HADS), and Athens Insomnia Scale (AIS) before the study, and at 4 and 8 weeks after study commencement. At the same times, body composition; blood pressure; heart rate; resting energy expenditures (REEs); and serum levels of triglyceride (TG), cholesterol, glucose, and hemoglobin A1c were measured.

Results

Ninety-three women (98%) completed the study. The following parameters showed significant changes, compared with baseline, at study weeks 4 and 8 (mean ± standard deviation at baseline, week 4, and week 8): (1) the MSS score improved (9.9 ± 5.2, 8.5 ± 5.0, 8.3 ± 5.0; P < 0.0001, repeated measures analysis of variance(ANOVA)), (2) the HADS-anxiety subscale score improved (5.3 ± 2.7, 4.8 ± 2.4, 4.9 ± 2.9; P = 0.041, Friedman test), (3) heart rate increased (62.6 ± 9.4 bpm, 64.4 ± 8.6 bpm, 63.8 ± 8.2 bpm; P = 0.028, Friedman test), (4) REE increased (1980 ± 368 kcal/day, 2108 ± 440 kcal/day, 2149 ± 470 kcal/day; P = 0.0030, repeated measures ANOVA), (5) serum TG level decreased in the subgroup of women (n = 22) who had high TG (150 mg/dL or higher) at baseline (237.8 ± 88.9 mg/dL, 166.7 ± 86.1 mg/dL, 170.9 ± 109.7 mg/dL; P = 0.0002, Friedman test).

Conclusions

Tomato juice intake alleviated menopausal symptoms, including anxiety, increased REEs and heart rate, and lowered high baseline serum TG levels in middle-aged women.

Trial registration

UMIN-CTRUMIN000011877.

In the clinic. Perimenopause

This issue provides a clinical overview of Perimenopause focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic.

[Factors influencing quality of life in patients with breast cancer on hormone therapy]

PURPOSE

The purpose of the study was to identify degrees of pain, menopause symptoms, and quality of life, and to identify factors influencing quality of life of patients with breast cancer who were on hormone therapy.

METHODS

A cross-sectional survey design was utilized. Data were collected using questionnaires from 110 patients with breast cancer who had been on hormone therapy for 3 months or more and were being treated at a university hospital in Seoul. Data were analyzed using χ²-test, t-test, ANOVA, Pearson correlation coefficient and multiple linear regression.

RESULTS

Mean age of the participants was 53.56 (SD=6.67) and 54 (51.4%) had stage 0 or I at the time of diagnosis. Most of the participants reported having pain and menopause symptoms (88.2% and 95.5% respectively). The mean score for quality of life was 87.84±21.17. Pain, menopause symptoms and quality of life had strong correlations with each other (p<.005). Quality of life was explained by menopause symptoms (β=-.71), economic status (β=.20) and occupation (β=.16).

CONCLUSION

The results of the study suggest that menopause symptoms should be incorporated into oncologic nursing care to improve quality of life of patients with breast cancer on hormone therapy.

Is desvenlafaxine effective and safe in the treatment of menopausal vasomotor symptoms? A meta-analysis and meta-regression of randomized double-blind controlled studies

BACKGROUND

During perimenopause, vasomotor symptoms are known to have a detrimental effect on women's functional ability and quality of life. For symptomatic women not eligible for hormonal therapy, desvenlafaxine is an option, but its safety margin and tolerability are not yet determined.

METHODS

A computer-based literature search was done in the databases of MEDLINE, Cochrane library, and HINARI (Health InterNetwork Access to Research Initiative). Meta-analysis was conducted by including double-blind randomized controlled studies on the effectiveness and safety of desvenlafaxine in the treatment of hot flashes. The effectiveness, safety and tolerability of desvenlafaxine were determined by standardized mean differences (SMDs) and Mantel-Haenszel odds ratio. Subgroup analysis based on doses of desvenlafaxine and linear meta-regression analyses were performed for several covariates. Heterogeneity testing, the risk of bias assessment and sensitivity analyses were done.

RESULTS

Desvenlafaxine was associated with a statistically significant reduction in the number and severity of daily moderate to severe hot flashes. The number of nighttime awakenings because of hot flashes was also significantly decreased. However, the rate of desvenlafaxine treatment discontinuation because of adverse events was a significantly higher than placebo treated women and the risk ratios of adverse events like asthenia, hypertension, anorexia, constipation, diarrhea, dry mouth, nausea, dizziness, insomnia, somnolence and mydriasis were very high.

CONCLUSION

Desvenlafaxine is effective in the treatment of hot flashes but it is strongly associated with several adverse events and treatment discontinuation. Further clinical trials focusing only on desvenlafaxine related adverse events are highly warranted before it is approved for public use.

Menopausal hormone therapy and menopausal symptoms

A majority of women will experience bothersome symptoms related to declining and/or fluctuating levels of estrogen during their menopausal transition. Vasomotor symptoms, vaginal dryness, poor sleep, and depressed mood have all been found to worsen during the menopausal transition. While vasomotor symptoms gradually improve after menopause, the time course can be many years. Vaginal dryness does not improve without treatment, while the long-term course of sleep and mood deterioration is not clearly defined at this time. A small minority of women have vasomotor symptoms that persist throughout the remainder of their lives. These common menopausal symptoms all improve with estrogen treatment. Over the last 10 years, we have witnessed a dramatic reduction in enthusiasm for menopausal hormone therapy, despite its high efficacy relative to other treatments. We have also seen the emergence of sound, evidence-based clinical trials of non-hormonal alternatives that can control the common menopausal symptoms. Understanding the natural history of menopausal symptoms, and the risks and benefits of both hormonal and non-hormonal alternatives, helps the clinician individualize management plans to improve quality of life.

The effect of gabapentin on intensity and duration of hot flashes in postmenopausal women: a randomized controlled trial

Background:

Menopause is the stage of time in which the menstruation stops following the loss of ovarian activity. The purpose of this study was to find out the effectiveness of gabapentin on hot flashes in postmenopausal women.

Materials and Methods:

A randomized controlled trial from Feb 2010 to 2011 was conducted. Sixty postmenopausal women who were referred to obstetrics and gynecology ward of two educational hospitals were recruited and divided into two groups (intervention and control). Intervention group received 300 mg gabapentin three times a day for three months, while control group received placebo. The Intensity and duration of hot flashes in women scored and recorded using visual analog scale. Independent, Paired t-test and chi-square test were used for analyzing data.

Results:

Intensity of hot flashes in the beginning of research in the intervention group was significantly different with the first, second and third follow-up visit (P<0.05). Also at the end of intervention a significant difference between intervention and control groups were observed regarding the intensity, frequency and duration of hot flashes (P<0.05 and P=0.01 respectively).

Conclusion:

According to the findings of this study; it appears that the use of gabapentin could decrease the intensity, duration and frequency of hot flashes in postmenopausal women. For postmenopausal women who hormone therapy is contraindicated, gabapentine could be an acceptable alternative.

Postmenopausal hormone therapy: risks and benefits

Postmenopausal hormone therapy (PMHT) is used for the relief of menopausal symptoms, but the dosage has varied greatly throughout its existence. By the end of the 1990s, PMHT was mainly used to prevent chronic diseases such as osteoporosis, coronary heart disease and dementia, and large prevention trials were undertaken in this context. Following the initial negative reports of these trials, use of PMHT dramatically decreased. These reports noted surprisingly increased risks, notably of coronary heart disease, stroke and breast cancer, in people who used PMHT. Nowadays, considering the currently available data, it seems that an important distinction should be made between the treatment of climacteric symptoms in young, generally healthy, postmenopausal women and the prevention of chronic diseases in elderly women. PMHT seems to be beneficial and safe for postmenopausal symptomatic women aged <60 years. Treatments with a high safety profile should be the preferred option, including low-dose PMHT, oestrogen-only therapy in women who have had a hysterectomy, and vaginal oestrogen therapy for women with atrophic vaginitis. Nonandrogenic progestin might have a reduced thrombotic and breast cancer risk, and transdermal oestrogen could have a reduced thrombotic risk. Nevertheless, PMHT should not be used for the prevention of chronic diseases in the elderly (>70 years old) owing to the increased risk of stroke and breast cancer in these patients.

Comparison of Gabapentin with Estrogen for treatment of hot flashes in post-menopausal women

OBJECTIVE

Various non-hormonal agents have been used for the treatment of hot flashes in women with menopause. Some studies have reported that gabapentin appears to be an effective and well-tolerated treatment modality. The aim of this study was to evaluate whether the treatment with gabapentin is effective in reducing hot flash frequency and severity and also to compare gabapentin 100 mg/day, 300 mg/day and conjugated estrogen in this regards.

METHODS

In this comparative clinical trial, 100 post-menopausal women attending outpatient clinics of Isfahan University hospitals were included from April 2008 to February 2009. Participants randomly received gabapentin 300 mg/day, gabapentin 100 mg/day, or conjugated estrogen 0.625 mg/day for 12 weeks. Frequency and severity of hot flashes and adverse effects were compared among the three groups.

FINDINGS

From all, 16 participants dropped out. There were no significant differences among the groups before intervention in terms of age, body mass index and baseline hot flash frequency and severity. Hot flash diaries were used to record the frequency and severity of hot flashes. After the treatment period, there was a significant decrease in both severity and frequency of hot flashes in all three groups. Post-hoc analyses showed that the frequency and severity of hot flashes were significantly lower in those who received gabapentin 300 mg/day or estrogen 0.625 mg/day compared to those who received gabapentin 100 mg/day. There was not statistically significant difference between those who received gabapentin 300 mg/day and those who received estrogen. Very few adverse effects, mostly gastrointestinal discomfort were observed in both gabapentin groups (8%).

CONCLUSION

Gabapentin 300 mg/day could be useful to relieve hot flashes in women for whom hormone therapy is not suitable or when hot flashes do not respond to other therapies. Further researches are needed to determine the efficacy of gabapentin use for longer periods or at higher doses.

Non-estrogen conventional and phytochemical treatments for vasomotor symptoms: what needs to be known for practice

OBJECTIVE

Non-hormonal treatment for menopausal vasomotor symptoms (VMS) is needed in women in whom there are medical or personal concerns on the use of hormone therapy. This paper reviews conventional and phytochemical therapies available for the relief of VMS, on their mechanisms of action, their efficacy and safety concerns.

METHODS

Medline was searched through Pubmed on the names of the diverse therapies analyzed, up to June 2011. The Cochrane Controlled Clinical Trials Register Database was searched for relevant trials that provided data on treatment of menopausal hot flushes.

RESULTS

All non-estrogen treatments for VMS are less efficacious than estrogen treatment. Randomized trials with neuroendocrine agents show globally modest to moderate reduction of VMS and frequent bothersome adverse events. The variability of effects makes it possible to undergo treatment in search for individual response where estrogen treatment is contraindicated. The antidepressants that interact with cytochrome P450, inhibiting tamoxifen metabolism to endoxifen, interfere with tamoxifen therapy in breast cancer patients. Otherwise, botanical products containing isoflavones from soy bean or red clover have great variability in bioavailability, have a broader spectrum of action than estradiol, and have predominant estrogen receptor-b activity. The efficacy of phytoestrogens on VMS is similar to placebo. They should be avoided in women with breast cancer and, in particular, in women being treated with tamoxifen or aromatase inhibitors due to possible antagonism. Cimicifuga racemosa is not a phytoestrogen, has partial serotonin agonist action and has a modest effect on VMS.

CONCLUSIONS

There are safe non-hormonal conventional treatments for menopausal VMS, although they are less efficacious than estrogens. The indication of phytochemicals is for women who make this choice on personal beliefs; long-term studies of larger groups of patients are needed to assess safety.

Primary menopausal insomnia: definition, review, and practical approach

OBJECTIVE

To present a case of primary menopausal insomnia with hot flashes to introduce recent changes in technology and nomenclature of sleep medicine and to review presentation, diagnosis, and therapies for menopausal insomnia.

METHODS

Clinical findings and results of sleep evaluation in the menopausal study patient are presented with details about polysomnography performed before and after therapy with pregabalin.

RESULTS

A 56.5-year-old female athlete with severe hot flashes and insomnia of 12 years' duration was treated with pregabalin, which ameliorated the hot flashes and sweats and improved sleep quality and architecture. Menopause is associated with hormonal and metabolic changes that disrupt sleep. Disruption of sleep can in turn lead to morbidity and metabolic sequelae. Hormonal treatment, although effective, carries risks unacceptable to many patients and physicians. To date, nonhormonal therapies of symptomatic menopause have not been objectively studied for effects on sleep efficiency and architecture. Primary menopausal insomnia is insomnia associated with menopause and not attributable to secondary causes. Polysomnographically, it seems characterized by a high percentage of slow-wave (N3) sleep, decreased rapid eye movement sleep, cyclic alternating pattern, and arousals.

CONCLUSIONS

Primary menopausal insomnia is probably mediated through a mechanism separate from hot flashes, and one can occur without the other. Thermal dys-regulation and sleep abnormalities of menopause are probably related to more general changes mediated through loss of estrogenic effects on neuronal modulation of energy metabolism, and more clinical direction is expected as this research field develops. Identification of sleep disorders in menopausal women is important, and polysomnographic evaluation is underused in both clinical and research evaluations of metabolic disturbances.

Non-hormonal treatment strategies for vasomotor symptoms: a critical review

Hot flashes (or flushes) are the most commonly reported symptoms during the menopause transition and early postmenopausal years, particularly in Western societies; they affect 60-90% of women and can lead to significant physical discomfort and functional impairment. The emergence of hot flashes and night sweats (also known as vasomotor symptoms [VMS]) coincide with a period in life that is also marked by dynamic changes in hormone and reproductive function that interconnect with the aging process, changes in metabolism, lifestyle behaviours and overall health. Estrogen-based therapies have long been the treatment of choice for women suffering from VMS. More recent concerns over long-term safety of menopausal hormone treatments, however, have led physicians and patients to pursue non-hormonal strategies to alleviate their symptoms. In this article, we review most of the efficacy and safety data on non-hormonal treatments for VMS published over the past 20 years. We discuss the evidence for treating symptomatic women in different clinical scenarios, e.g. VMS with and without concomitant depression or VMS following the use of anti-estrogen therapies. Overall, efficacy data support the use of some psychotropic medications, including selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors and gabapentin. Complementary and alternative methods for VMS also showed limited but promising results, although more definitive studies are warranted. Clinicians should therefore be able to tailor treatment strategies for those who are unable or unwilling to use hormones to alleviate VMS and improve overall functioning and quality of life.

Gabapentin and pregabalin in the treatment of fibromyalgia: a systematic review and a meta-analysis

WHAT IS KNOWN AND OBJECTIVES

Fibromyalgia (FBM) is a common chronic pain disorder affecting up to 2% of the general population. Current treatment options are mostly symptom-based and limited both in efficacy and number. Two promising alternatives are gabapentin (GP) and pregabalin (PB). We aimed to estimate the efficacy and safety/tolerability of the two compounds in FBM through a systematic review and a meta-analysis of relevant randomized double-blind placebo-controlled (RCT) were performed.

DATA SOURCES, EXTRACTION AND ANALYSIS

A literature search was conducted through MEDLINE, EMBASE, Cochrane CENTRAL and the reference lists of relevant studies. Responders to treatment (>30% reduction in mean pain score) and dropouts due to lack of efficacy were used as primary outcome measures. Dropout rates and incidence of common adverse outcomes were also investigated. Four RCTs, reporting data on 2040 patients, were reviewed and three of them using PG were included in the meta-analysis.

RESULTS

Pregabalin at a dose of 600, 450 and 300 mg per day is effective in FBM compared to placebo (NNT: 7, upper 95% CI: 12, 450 mg). A number of adverse events (AE), such as dizziness, somnolence, dry mouth, weight gain, peripheral oedema, is consistently associated with treatment at any dose and could lead one out of four patients to quit treatment (NNH: 6, lower 95% CI: 4, 600 mg). Indirect comparison meta-analysis suggests that PB at a dose of 450 mg per day could result in more responders than at 300 mg, but this result needs to be interpreted with caution as there were no significant differences between 600 and 300 mg or between 600 and 450 mg. Data on GP is limited.

WHAT IS NEW AND CONCLUSIONS

The analysis indicates that PB at a dose of 450 mg per day is most likely effective in treating FBM, although AE are not negligible. Further evidence is necessary for more conclusive inferences.

Medication Repurposing: New Uses for Old Drugs

Background:

Medication repurposing, the practice of using old drugs in new ways, is becoming more common. Old drugs that had previously fallen out of favor due to safety concerns, lack of efficacy, or development of more desirable therapeutic alternatives have been resurfacing in the literature and on pharmacy shelves. Developing new uses for old drugs may provide patients with access to helpful therapies but may also present challenges and risks.

Objective:

To explore the rationale for, and historical context of, the developing trend of recycling existing drugs for new, innovative uses, and to provide pharmacy practitioners with information about how to find clinical evidence regarding these new uses.

Data Synthesis:

The process of obtaining marketing approval for new drugs can take an average of over 10 years and exceed $1 billion. Repurposing old drugs (both approved and unapproved) for new uses requires considerably fewer resources since information about production needs, pharmacology, and pharmacokinetics is already known. Other advantages of using old drugs include faster availability for patient use and known safety concerns for the original indication. Disadvantages of new uses for old drugs may include lack of clinical evidence, unknown safety for the new clinical context, limited availability of information about new uses, and liability or legal concerns. Several methods of identifying potential new uses exist, including the observance of previously unknown desirable pharmacologic effects during clinical use, new knowledge of a mechanism of action leading to exploration of innovative therapeutic areas, or screening compound libraries for targeted clinical activity.

Conclusions:

There are many examples of recycling existing medications for new purposes. Pharmacy practitioners should be aware of this developing trend and know how to find information about utilizing old drugs in new ways.

Managing menopausal symptoms and depression in tamoxifen users: implications of drug and medicinal interactions

OBJECTIVE

Tamoxifen, a medication used in the treatment of breast cancer, often induces menopausal symptoms. Certain medications and natural supplements taken or prescribed to alleviate tamoxifen-induced hot flashes and depressive states in women with breast cancer interact with tamoxifen. This paper reviews potentially problematic interactions and offers treatment recommendations.

METHODS

Medline (1950-June 1, 2010), Embase Classic+Embase (1947-June 1, 2010) and PsycINFO (1967-June 1, 2010) were searched through Ovid. The word "tamoxifen" was searched with "depression" and then with "menopaus*" and "symptoms", with "treatment" as a limit. "Tamoxifen" was later searched with the MeSH terms "drug interaction" or "drug incompatibility".

RESULTS

Venlafaxine is efficacious for the treatment of hot flashes and depression and safe to use in combination with tamoxifen. Gabapentin is also efficacious in treating tamoxifen-induced hot flashes and, since it does not interact with cytochrome P450 system, is likely safe to use in patients using tamoxifen. Desvenlafaxine and pregabalin may be alternatives to venlafaxine and gabapentin, respectively, although desvenlafaxine has not yet been studied in this population. Paroxetine, fluoxetine and bupropion are strong CYP2D6 inhibitors which should be avoided in tamoxifen users. Fluvoxamine and nefazodone both inhibit CYP3A, which could potentially affect the metabolism of tamoxifen. Clonidine can be an alternative agent but may carry significant side effects. Evidence of medicinal products for the treatment of tamoxifen-induced hot flashes is equivocal at best.

CONCLUSIONS

Clinicians should remain cautious about using strong inhibitors and/or inducers of cytochrome 2D6 and 3A4 concomitantly with tamoxifen. Use of natural menopausal supplements and diets rich in isoflavones should not be encouraged in tamoxifen users until more data is available. There are however safe treatments for hot flashes and depression in tamoxifen users.