Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fibromyalgia syndrome

Advances in the Microbial Synthesis of 5-Hydroxytryptophan

5-Hydroxytryptophan (5-HTP) plays an important role in the regulation of emotion, behavior, sleep, pain, body temperature, and other physiological functions. It is used in the treatment of depression, insomnia, migraine, and other diseases. Due to a lack of effective biosynthesis methods, 5-HTP is mainly obtained by natural extraction, which has been unable to meet the needs of the market. Through the directed evolution of enzymes and the introduction of substrate supply pathways, 5-HTP biosynthesis and yield increase have been realized. This review provides examples that illustrate the production mode of 5-HTP and the latest progress in microbial synthesis.

Gut bacteria-derived 5-hydroxyindole is a potent stimulant of intestinal motility via its action on L-type calcium channels

Microbial conversion of dietary or drug substrates into small bioactive molecules represents a regulatory mechanism by which the gut microbiota alters intestinal physiology. Here, we show that a wide variety of gut bacteria can metabolize the dietary supplement and antidepressant 5-hydroxytryptophan (5-HTP) to 5-hydroxyindole (5-HI) via the tryptophanase (TnaA) enzyme. Oral administration of 5-HTP results in detection of 5-HI in fecal samples of healthy volunteers with interindividual variation. The production of 5-HI is inhibited upon pH reduction in in vitro studies. When administered orally in rats, 5-HI significantly accelerates the total gut transit time (TGTT). Deciphering the underlying mechanisms of action reveals that 5-HI accelerates gut contractility via activation of L-type calcium channels located on the colonic smooth muscle cells. Moreover, 5-HI stimulation of a cell line model of intestinal enterochromaffin cells results in significant increase in serotonin production. Together, our findings support a role for bacterial metabolism in altering gut motility and lay the foundation for microbiota-targeted interventions.

5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology

L-5-hydroxytryptophan (5-HTP) is both a drug and a natural component of some dietary supplements. 5-HTP is produced from tryptophan by tryptophan hydroxylase (TPH), which is present in two isoforms (TPH1 and TPH2). Decarboxylation of 5-HTP yields serotonin (5-hydroxytryptamine, 5-HT) that is further transformed to melatonin (N-acetyl-5-methoxytryptamine). 5-HTP plays a major role both in neurologic and metabolic diseases and its synthesis from tryptophan represents the limiting step in serotonin and melatonin biosynthesis. In this review, after an look at the main natural sources of 5-HTP, the chemical analysis and synthesis, biosynthesis and microbial production of 5-HTP by molecular engineering will be described. The physiological effects of 5-HTP are discussed in both animal studies and human clinical trials. The physiological role of 5-HTP in the treatment of depression, anxiety, panic, sleep disorders, obesity, myoclonus and serotonin syndrome are also discussed. 5-HTP toxicity and the occurrence of toxic impurities present in tryptophan and 5-HTP preparations are also discussed.

PK/PD modeling of 5-hydroxytryptophan (5-HTP) challenge test with cortisol measurement in serum and saliva

This research was planned to build a Pharmacokinetic/Pharmacodynamic (PK/PD) model of 5‐hydroxytryptophan (5‐HTP) challenge study including a circadian rhythm component of cortisol and to predict serum cortisol based on saliva cortisol. Data from three 5‐HTP challenge studies in healthy volunteers were collected. Serum 5‐HTP, saliva, and serum cortisol were sampled as PK and PD marker. The population PK/PD modeling approach was applied. A baseline model of serum cortisol was built to assess the circadian rhythm before a pharmacodynamic model was used to evaluate the drug effect of the 5‐HTP on cortisol. Finally, linear and power function relationships were tested to predict serum cortisol based on saliva cortisol. The PK of 5‐HTP could be described using a one‐compartment model with a transit compartment. The typical value for clearance was 20.40 L h⁻¹ and showed inter‐study variability. A cosine function was chosen and properly described the circadian rhythm of serum cortisol. A linear approximation model was applied to fit the 5‐HTP PD effect on cortisol data with a slope of 4.16 ng mL⁻¹ h. A power function provided a better description than a linear function to relate the saliva and serum cortisol. In conclusion, a circadian rhythm component was built in the PK/PD model of the 5‐HTP challenge test which could better improve the understanding of the stimulating effect on HPA with cortisol change. After the 5‐HTP challenge, saliva cortisol correlated well with serum cortisol and was predictable by a population PK‐PD model.

Slow-release delivery enhances the pharmacological properties of oral 5-hydroxytryptophan: mouse proof-of-concept

5-hydroxytryptophan (5-HTP) has shown therapeutic promise in a range of human CNS disorders. But native 5-HTP immediate release (IR) is poorly druggable, as rapid absorption causes rapid onset of adverse events, and rapid elimination causes fluctuating exposure. Recently, we reported that 5-HTP delivered as slow-release (SR) in mice augmented the brain pro-serotonergic effect of selective serotonin reuptake inhibitors (SSRIs), without the usual adverse events associated with 5-HTP IR. However, our previous study entailed translational limitations, in terms of route, dose, and duration. Here we modeled oral 5-HTP SR in mice by administering 5-HTP via the food. We modeled oral SSRI treatment via fluoxetine in the water, in a regimen recapitulating clinical pharmacokinetics and pharmacodynamics. 5-HTP SR produced plasma 5-HTP levels well within the range enhancing brain 5-HT function in humans. 5-HTP SR robustly increased brain 5-HT synthesis and levels. When administered with an SSRI, 5-HTP SR enhanced 5-HT-sensitive behaviors and neurotrophic mRNA expression. 5-HTP SR's pro-serotonergic effects were stronger in mice with endogenous brain 5-HT deficiency. In a comprehensive screen, 5-HTP SR was devoid of overt toxicological effects. The present preclinical data, appreciated in the context of published 5-HTP clinical data, suggest that 5-HTP SR could represent a new therapeutic approach to the plethora of CNS disorders potentially treatable with a pro-serotonergic drug. 5-HTP SR might in particular be therapeutically relevant when brain 5-HT deficiency is pathogenic and as an adjunctive augmentation therapy to SSRI therapy.

A new oxidative stress indicator: Effect of 5-hydroxytryptophan on thiol-disulfide homeostasis in exercise

OBJECTIVES

The aim of the present study was to evaluate the relationship between exercise and both 5-hydroxytryptophan and oxidative stress using thiol-disulfide homeostasis via what is likely a novel biomarker.

METHODS

Male albino Wistar rats (n = 32) were randomly divided into four groups as follows: control, exercise group, 5-hydroxytryptophan group (5H), and 5-HTP + exercise group (5Hex). Exercise and 5-HTP administration (25mg/kg per d) were performed 5d/wk for 10 wk. After completion of the experimental protocol, to determine oxidative stress parameters, serum total thiol and native thiol concentrations were measured. Dynamic disulfide status, reduced thiol, oxidized thiol (OT), and thiol oxidation reduction percentage ratios were compared between the groups. The methods used in the present study to measure dynamic thiol-disulfide homeostasis as calorimetric and duplex quantities were developed in 2014. These new methods are simple, reliable, and sensitive, with both high linearity and repeatability.

RESULTS

Compared with the control group, serum dynamic disulfide levels were significantly lower in the 5H group and highest in the control group. The lowest OT and the highest reduced thiol rates were determined to be in the 5H group. The highest OT value was found in the 5Hex group. Thiol oxidation reduction values were found to be highest in the 5H group and lowest in the 5Hex group.

CONCLUSIONS

Both 5-HTP and moderate exercise seem to be significantly effective in inhibiting oxidative damage. In addition, the new oxidative stress measurement method used in this study is a promising practical and useful method to evaluate and improve the performance of athletes.

[Complementary and alternative therapies for fibromyalgia syndrome. Systematic review, meta-analysis and guideline]

BACKGROUND

The scheduled update to the German S3 guidelines on fibromyalgia syndrome (FMS) by the Association of the Scientific Medical Societies ("Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften", AWMF; registration number 041/004) was planned starting in March 2011.

MATERIALS AND METHODS

The development of the guidelines was coordinated by the German Interdisciplinary Association for Pain Therapy ("Deutsche Interdisziplinären Vereinigung für Schmerztherapie", DIVS), 9 scientific medical societies and 2 patient self-help organizations. Eight working groups with a total of 50 members were evenly balanced in terms of gender, medical field, potential conflicts of interest and hierarchical position in the medical and scientific fields. Literature searches were performed using the Medline, PsycInfo, Scopus and Cochrane Library databases (until December 2010). The grading of the strength of the evidence followed the scheme of the Oxford Centre for Evidence-Based Medicine. The recommendations were based on level of evidence, efficacy (meta-analysis of the outcomes pain, sleep, fatigue and health-related quality of life), acceptability (total dropout rate), risks (adverse events) and applicability of treatment modalities in the German health care system. The formulation and grading of recommendations was accomplished using a multi-step, formal consensus process. The guidelines were reviewed by the boards of the participating scientific medical societies.

RESULTS AND CONCLUSION

Meditative movement therapies (qi gong, tai chi, yoga) are strongly recommended. Acupuncture can be considered. Mindfulness-based stress reduction as monotherapy and dance therapy as monotherapy are not recommended. Homeopathy is not recommended. In a minority vote, homeopathy was rated as "can be considered". Nutritional supplements and reiki are not recommended. The English full-text version of this article is available at SpringerLink (under "Supplemental").

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.

Neurofeedback intervention in fibromyalgia syndrome; a randomized, controlled, rater blind clinical trial

We designed a randomized, rater blind study to assess the efficacy of EEG Biofeedback (Neurofeedback-NFB) in patients with fibromyalgia syndrome (FMS). Eighteen patients received twenty sessions of NFB-sensory motor rhythm (SMR) treatment (NFB group) during 4 weeks, and eighteen patients were given 10 mg per day escitalopram treatment (control group) for 8 weeks. Visual Analog Scales for pain and fatigue, Hamilton and Beck Depression and Anxiety Inventory Scales, Fibromyalgia Impact Questionnaire and Short Form 36 were used as outcome measures which were applied at baseline and 2nd, 4th, 8th, 16th, 24th weeks. Mean amplitudes of EEG rhythms (delta, theta, alpha, SMR, beta1 and beta2) and theta/SMR ratio were also measured in NFB group. All post-treatment measurements showed significant improvements in both of the groups (for all parameters p < 0.05). NFB group displayed greater benefits than controls (for all parameters p < 0.05). Therapeutic efficacy of NFB was found to begin at 2nd week and reached to a maximum effect at 4th week. On the other hand, the improvements in SSRI treatment were also detected to begin at 2nd week but reached to a maximum effect at 8th week. No statistically significant changes were noted regarding mean amplitudes of EEG rhythms (p > 0.05 for all). However, theta/SMR ratio showed a significant decrease at 4th week compared to baseline in the NFB group (p < 0.05). These data support the efficacy of NFB as a treatment for pain, psychological symptoms and impaired quality of life associated with fibromyalgia.

Alternative medical interventions used in the treatment and management of myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia

BACKGROUND

There have been several systematic reviews attempting to evaluate the efficacy of possible treatments for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia (FM). However, information regarding the efficacy of complementary and alternative medicine (CAM) has not been comprehensively or systematically covered in these reviews, despite its frequent use in the patient community.

PURPOSE

The purpose of this study was to systematically review and evaluate the current literature related to alternative and complementary treatments for ME/CFS and FM. It should be stressed that the treatments evaluated in this review do not reflect the clinical approach used by most practitioners to treat these illnesses, which include a mix of natural and unconventionally used medications and natural hormones tailored to each individual case. However, nearly all clinical research has focused on the utility of single CAM interventions, and thus is the primary focus of this review.

METHODS

Several databases (e.g., PubMed, MEDLINE,((R)) PsychInfo) were systematically searched for randomized and nonrandomized controlled trials of alternative treatments and nonpharmacological supplements. Included studies were checked for references and several experts were contacted for referred articles. Two leading subspecialty journals were also searched by hand. Data were then extracted from included studies and quality assessments were conducted using the Jadad scale.

RESULTS

Upon completion of the literature search and the exclusion of studies not meeting criterion, a total of 70 controlled clinical trials were included in the review. Sixty (60) of the 70 studies found at least one positive effect of the intervention (86%), and 52 studies also found improvement in an illness-specific symptom (74%). The methodological quality of reporting was generally poor.

CONCLUSIONS

Several types of alternative medicine have some potential for future clinical research. However, due to methodological inconsistencies across studies and the small body of evidence, no firm conclusions can be made at this time. Regarding alternative treatments, acupuncture and several types of meditative practice show the most promise for future scientific investigation. Likewise, magnesium, l-carnitine, and S-adenosylmethionine are nonpharmacological supplements with the most potential for further research. Individualized treatment plans that involve several pharmacological agents and natural remedies appear promising as well.

Pharmacological treatment of fibromyalgia syndrome: new developments

Fibromyalgia is a chronic pain disorder characterized by widespread pain, stiffness, insomnia, fatigue and distress. Several randomized controlled trials (RCTs) have shown moderate effectiveness of pharmacological therapies for fibromyalgia pain. Evidence from these trials suggests that pharmacological therapy can not only improve pain but also fatigue, function and well-being in patients with fibromyalgia. Duloxetine and milnacipran, two highly selective serotonin-norepinephrine (noradrenaline) reuptake inhibitors, and the alpha(2)delta agonist pregabalin have been approved by the US FDA for the treatment of fibromyalgia symptoms. In general, about half of all treated patients seem to experience a 30% reduction of symptoms, suggesting that many patients with fibromyalgia will require additional therapies. Thus, other forms of treatment, including exercise, cognitive behavioural therapies and self-management strategies, may be necessary to achieve satisfactory treatment outcomes. Despite promising results of pilot trials, RCTs with dopamine receptor agonists and sodium channel antagonists have so far been disappointing for patients with fibromyalgia. However, new pharmacological approaches for the treatment of fibromyalgia pain and insomnia using sodium oxybate appear to be promising.

[Alternative and complementary therapies in fibromyalgia syndrome]

INTRODUCTION

Interdisciplinary S3 level guidelines were devised in cooperation with 8 medical, 2 psychological and 2 patient support groups. Results were elaborated in a multilevel group process.

METHODS

On the bases of the "Cochrane Library" (1993-2006), "Medline" (1980-2006), "PsychInfo" (2006) and "Scopus" (2006) controlled studies and meta-analyses of controlled studies were analyzed.

RESULTS

Only few controlled studies were found supporting in part the effectiveness of CAM therapies in the treatment of fibromyalgia syndrome. Due to the lack of information on long term efficacy and cost-effectiveness, only limited recommendations for CAM therapies can be given.

CONCLUSION

Within a multicomponent therapy setting, selective CAM therapies (acupuncture, vegetarian diet, homeopathy, Tai Chi, Qi Gong, music-oriented and body-oriented therapies) can be recommended for a limited period of time.

Fibromyalgia syndrome: approach to management

The management of fibromyalgia syndrome (FMS) has traditionally been multimodal and multidisciplinary, including education, physical modalities, and medication. In this article, an acronym is offered to help the clinician remember the important components of management. An improved understanding of the pathogenesis of FMS has allowed substantial refinements in its treatment. This is particularly true for medications that target specific symptom domains, allowing individualization of therapy. Since all FMS patients experience pain, there has been emphasis on that domain although medications are now available to address two or more domains with monotherapy. In addition, a logical basis is provided to help the clinician design strategic polypharmacy..

Treatment of fibromyalgia and its symptoms

The main symptoms of fibromyalgia syndrome (FM) are pain, stiffness, subjective weakness and muscle fatigue. Pain in FM usually fluctuates, as well as being 'deep' and is always associated with local or generalized tenderness (hyperalgesia and allodynia). The pathogenesis of such peripheral and/or CNS changes in FM is unclear, but peripheral tissue changes, specifically in muscles, have been implicated. Indirect evidence from interventions that attenuate tonic peripheral impulse input in patients with FM suggest that overall FM pain is dependent on nociception. More importantly, FM-associated widespread mechanical hyperalgesia and allodynia can also be improved or abolished by removal of peripheral pain impulse input. In addition, FM patients show evidence of abnormal stress reactivity, including blunting of the hypothalamic-pituitary-adrenal axis and increased autonomic nervous system responsiveness. Thus, therapeutic interventions in FM should target not only pain reductions, but also improvements of peripheral/central sensitization and neuroendocrine/autonomic abnormalities. Despite the complexity of FM, there are pharmacologic and non-pharmacologic interventions that are available that have clinical benefit. Present evidence indicates efficacy of antidepressants, cardiovascular exercise and cognitive behavioral therapy. Based on this evidence, a stepwise program emphasizing education, medications, exercise and cognitive therapy can be recommended.

Pharmacological treatment of fibromyalgia and other chronic musculoskeletal pain

The pharmacologic management of fibromyalgia is based on the emerging evidence that pain in this disorder is primarily related to central pain sensitization. There is strong evidence that tricyclic antidepressants are effective, and moderate evidence for the effectiveness of serotonin reuptake inhibitors and dual serotonin-norepinephrine reuptake inhibitors. Recent work suggests that the anti-seizure medications pregabalin and gabepentin are also effective. The only analgesic demonstrated to be helpful is tramadol.

Pharmacologic treatment of fibromyalgia

Fibromyalgia is a syndrome of widespread pain, nonrestorative sleep, disturbed mood, and fatigue. Optimal treatment involves a multidisciplinary approach with a team of health care providers using pharmacologic and nonpharmacologic treatment. Because of the heterogeneity of the illness, management should be individualized for the patient. Pharmacologic treatment should address issues of pain control, sleep disturbance, fatigue, and any underlying coexisting mood disorder. Nonpharmacologic treatment should include patient education, a regular exercise and stretching program, and cognitive behavioral therapy. All of these are essential to improving functional capacity and quality of life. This review provides general guidelines in initiating a successful pharmacologic treatment program for patients with fibromyalgia.

Use of complementary and alternative medical therapies by patients referred to a fibromyalgia treatment program at a tertiary care center

OBJECTIVE

To evaluate the frequency and pattern of complementary and alternative medicine (CAM) use in patients referred to a fibromyalgia treatment program at a tertiary care center.

PATIENTS AND METHODS

Patients referred to the Mayo Fibromyalgia Treatment Program between February 2003 and July 2003 were invited on their initial visit to participate in a survey regarding CAM use during the previous 6 months. An 85-question survey that addressed different CAM domains was used.

RESULTS

Of the 304 patients invited to participate, 289 (95%) completed the survey (263 women and 26 men). Ninety-eight percent of the patients had used some type of CAM therapy during the previous 6 months. The 10 most frequently used CAM treatments were exercise for a specific medical problem (48%), spiritual healing (prayers) (45%), massage therapy (44%), chiropractic treatments (37%), vitamin C (35%), vitamin E (31%), magnesium (29%), vitamin B complex (25%), green tea (24%), and weight-loss programs (20%).

CONCLUSION

CAM use is common in patients referred to a fibromyalgia treatment program.

Safety of 5-hydroxy-L-tryptophan

5-Hydroxy-L-tryptophan (5-HTP) is the immediate precursor in the biosynthesis of 5-hydroxy-tryptamine (5-HT; serotonin) from the essential amino acid L-tryptophan (L-Trp). The use of L-Trp as a dietary supplement was discontinued in 1989 due to an outbreak of eosinophilia-myalgia syndrome (EMS) that was traced to a contaminated synthetic L-Trp from a single manufacturer. 5-HTP has since become a popular dietary supplement in lieu of the removal of L-Trp from the market. Because of its chemical and biochemical relationship to L-Trp, 5-HTP has been under vigilance by consumers, industry, academia and government for its safety. However, no definitive cases of toxicity have emerged despite the worldwide usage of 5-HTP for last 20 years, with the possible exception of one unresolved case of a Canadian woman. Extensive analyses of several sources of 5-HTP have shown no toxic contaminants similar to those associated with L-Trp, nor the presence of any other significant impurities. A minor chromatographic peak (peak X) reported in some 5-HTP samples lacks credibility due to chromatographic artifacts and infinitesimal concentrations, and has raised undue speculations concerning its chemistry and toxicity.

Treatment of fibromyalgia with cyclobenzaprine: A meta-analysis

OBJECTIVE

To systematically review the effectiveness of cyclobenzaprine in the treatment of fibromyalgia.

METHODS

Articles describing randomized, placebo-controlled trials of cyclobenzaprine in people with fibromyalgia were obtained from Medline, EMBase, Psyclit, the Cochrane Library, and Federal Research in Progress Database. Unpublished literature and bibliographies were also reviewed. Outcomes, including global improvement, treatment effects on pain, fatigue, sleep, and tender points over time, were abstracted.

RESULTS

Five randomized, placebo-controlled trials were identified. The odds ratio for global improvement with therapy was 3.0 (95% confidence interval [95% CI] 1.6-5.6) with a pooled risk difference of 0.21 (95% CI 0.09-0.34), which calculates to 4.8 (95% CI 3.0-11) individuals needing treatment for 1 patient to experience symptom improvement. Pain improved early on, but there was no improvement in fatigue or tender points at any time.

CONCLUSION

Cyclobenzaprine-treated patients were 3 times as likely to report overall improvement and to report moderate reductions in individual symptoms, particularly sleep.

Atypical depression spectrum disorder - neurobiology and treatment

Depressive syndromes are a group of heterogeneous disorders. Atypical depression (AD) with reversed vegetative signs, such as hyperphagia or hypersomnia, is traditionally neglected, demonstrated by the fact that in the most widely used depression scales, such as the Hamilton Depression Scale (HAMD), melancholic symptoms have a specific weight, while, by contrast, reversed vegetative signs are not included. However, epidemiologically and phenomenologically related disorders to AD do exist, such as somatoform disorders, neurasthenia (chronic fatigue syndrome) and fibromyalgia (FM). In this spectrum, here called the AD spectrum, instead a decrease in hypothalamus-pituitary-adrenocortical (HPA) axis activity seems to exist. This has similarities to Cushing's disease, where a suppression of central HPA system activity is accompanied by features of AD and somatization in a considerable number of patients. Opposite vegetative features might therefore be related to the opposite dysregulation of the HPA system. The psychopharmacological intervention in the AD spectrum should therefore differ from that used in typical major depression. MAO inhibitors, low-dose tricyclic antidepressants and 5-HT3 antagonists demonstrated therapeutic efficacy, but the existing studies focused on different aspects. Hypericum extracts might be an alternative pharmacological intervention, which demonstrated therapeutic efficacy in the symptom range of the spectrum.

Review of the implications of dietary tryptophan intake in patients with irritable bowel syndrome and psychiatric disorders

In this review, we address the possible role of the essential amino acid L-tryptophan or its metabolic derivative 5-hydroxytryptophan in the modulation of serotonin (5-hydroxytryptamine) synthesis and thereby in affecting the pathophysiology of central and peripheral nervous system disorders, including depression and irritable bowel syndrome. L-Tryptophan may represent a link between apparently disparate functional disorders and is of interest for general gastroenterologists, neurogastroenterologists, and neurologists. On the basis of estimates showing that approximately 20% of patients with functional bowel disorders seeking care in referral centres have psychiatric comorbidity, we attempt to provide a conceptual framework for defining the possible role of L-tryptophan in this population.

Tramadol and acetaminophen combination tablets in the treatment of fibromyalgia pain: a double-blind, randomized, placebo-controlled study

PURPOSE

To evaluate the efficacy and safety of a combination analgesic tablet (37.5 mg tramadol/325 mg acetaminophen) for the treatment of fibromyalgia pain.

METHODS

This 91-day, multicenter, double-blind, randomized, placebo-controlled study compared tramadol/acetaminophen combination tablets with placebo. The primary outcome variable was cumulative time to discontinuation (Kaplan-Meier analysis). Secondary measures at the end of the study included pain, pain relief, total tender points, myalgia, health status, and Fibromyalgia Impact Questionnaire scores.

RESULTS

Of the 315 subjects who were enrolled in the study, 313 (294 women [94%], mean [+/- SD] age, 50 +/- 10 years) completed at least one postrandomization efficacy assessment (tramadol/acetaminophen: n = 156; placebo: n = 157). Discontinuation of treatment for any reason was less common in those treated with tramadol/acetaminophen compared with placebo (48% vs. 62%, P = 0.004). Tramadol/acetaminophen-treated subjects also had significantly less pain at the end of the study (53 +/- 32 vs. 65 +/- 29 on a visual analog scale of 0 to 100, P <0.001), and better pain relief (1.7 +/- 1.4 vs. 0.8 +/- 1.3 on a scale of -1 to 4, P <0.001) and Fibromyalgia Impact Questionnaire scores (P = 0.008). Indexes of physical functioning, role-physical, body pain, health transition, and physical component summary all improved significantly in the tramadol/acetaminophen-treated subjects. Discontinuation due to adverse events occurred in 19% (n = 29) of tramadol/acetaminophen-treated subjects and 12% (n = 18) of placebo-treated subjects (P = 0.09). The mean dose of tramadol/acetaminophen was 4.0 +/- 1.8 tablets per day.

CONCLUSION

A tramadol/acetaminophen combination tablet was effective for the treatment of fibromyalgia pain without any serious adverse effects.

Management of sleep disorders in fibromyalgia

In summary, the treatment of patients with FM requires a proper assessment of the reason for the unrefreshing sleep, which is an important component of the FM syndrome. Sleep laboratory investigations provides a suitable rationale for management where a specific primary sleep disorder is determined. Nonspecific treatments include various behavioral approaches to improve sleep hygiene, fitness, and regular proper nutrition that serve to regularize disturbances in circadian sleep-wake rhythms. As yet, no medication is known to improve the EEG sleep arousal disorders that include phasic (alpha-delta), tonic alpha non-REM sleep disorders, or the periodic K alpha cycling alternating pattern disorder. Traditional hypnotic agents, while helpful in initiating and maintaining sleep and reducing daytime tiredness, do not provide restorative sleep or reduce pain. Tricyclic drugs, such as amitriptyline and cyclobenzaprine, may provide long term benefit for improving sleep but may not have a continuing benefit beyond one month for reducing pain. The use of a biologic agent that facilitates sleep-related neuroendocrine functions, for example growth hormone, is reported to improve symptoms but the need for injection and high cost restrict its use. No systematic studies have been reported on the use of remedial measures for the management of PLMS/restless legs syndrome and sleep apnea that occur in some patients with FM.

Treatment of fatigue in fibromyalgia

Clearly, fatigue is a large and challenging problem for those suffering from fibromyalgia. It adds greatly to the morbidity and disability associated with the disease. In the management of this specific symptom in fibromyalgia, attention should first be focused on identifying comorbidities that may be present and contribute to fatigue. As with other symptoms of fibromyalgia, education is a critical component of management. This can be done by the practitioner, with available free resources, or with specialized cognitive behavioral programs. This education process can be augmented with a variety of other nonpharmacologic therapies, especially very gradually increasing, low-impact, aerobic exercise programs. Numerous pharmacologic therapies may also be helpful as an adjunct to treatment. Classes of compounds that raise central levels of norepinephrine or dopamine appear to be the most specific for management of fatigue. There are also many medications used to combat fatigue in other disorders that have not yet been adequately explored as to the possible benefits in alleviating the fatigue of fibromyalgia. Advances in the management of fatigue in fibromyalgia are likely to come from a variety of directions. Easier access to well designed nonpharmacologic therapies is essential, because these treatments are underutilized in clinical practice at present. Improvements in pharmacologic therapies will come from new insights into mechanisms, especially those that might only be present in subsets of patients and would respond to more targeted therapies.

Rational and targeted pharmacologic treatment of fibromyalgia

Despite disappointing results when subjected to randomized clinical trials, pharmacologic agents remain an important component of FM management. Addressing the main symptoms of pain, disturbed sleep, mood disturbances, fatigue, and associated conditions is essential to improve patient functioning and enhanced quality of life. However, much work remains to design clinical trials which address the complexity of FM, while satisfying evidence based medicine paradigms.

Serotonergic agents in the treatment of fibromyalgia syndrome

OBJECTIVE

To evaluate literature that discusses the treatment of fibromyalgia syndrome (FMS) with agents that involve the neurotransmitter serotonin.

DATA SOURCES

Biomedical literature accessed through MEDLINE (1966-August 2001) and International Pharmaceutical Abstracts.

DATA SYNTHESIS

The cause and pathophysiology of FMS remain elusive, although abnormalities in the serotonin pathway have been implicated. Several serotonergic agents have been studied for use in FMS. Trials and case reports focusing on the use of newer agents: the selective serotonin reuptake inhibitors, venlafaxine and tramadol, were reviewed.

CONCLUSIONS

Current research suggests that the serotonergic agents may reduce at least some of the symptoms of FMS. However, medications that act on multiple neurotransmitters may prove to be more effective in symptom management. Additional long-term studies are required in order to validate these results.

Efficacy and tolerability of tropisetron in primary fibromyalgia--a highly selective and competitive 5-HT3 receptor antagonist. German Fibromyalgia Study Group

OBJECTIVE

Based on a potential role for serotonin receptors in fibromyalgia, we investigated the efficacy and tolerability of treatment with tropisetron, a highly selective, competitive inhibitor of the 5-HT3 receptor.

METHODS

In this prospective, multicenter, double-blind, parallel-group, dose-finding study, 418 patients suffering from primary fibromyalgia (ACR criteria) were randomly assigned to receive either placebo, 5 mg, 10 mg or 15 mg tropisetron once daily, respectively. The duration of treatment was 10 days. The clinical response was measured by changes in pain-score, visual analog scale (VAS), and the number of painful tender-points.

RESULTS

Treatment with 5 mg tropisetron resulted in a significantly higher response rate (39.2%) when compared with placebo (26.2%) (p=0.033). The absolute reduction in pain-score was -13.5% for 5 mg tropisetron, -13.0% for 10 mg tropisetron, and -6.3% for placebo (p<0.05). The effects of 15 mg tropisetron were similar to placebo, thus suggesting a bell-shaped dose-response curve. Compared with placebo, treatment with 5 mg tropisetron led to a significant improvement (p<0.05) in VAS, while a clear trend in terms of clinical benefit was seen with 10 mg tropisetron. The number of painful tender-points was also reduced significantly (p=0.002) in the 5 mg tropisetron group. Of interest, during the 12-month follow-up period, pain intensity of responders on 5 mg and 10 mg tropisetron was still markedly below baseline. The treatment was well tolerated, with gastro-intestinal complaints being the most frequently reported side effects, in keeping with the known safety profile for 5-HT3 receptor antagonists.

CONCLUSIONS

This study demonstrates the efficacy of short-term treatment with 5 mg tropisetron once daily in primary fibromyalgia. Treatment was well tolerated and prolonged clinical benefits were seen.

DL-phenylalanine markedly potentiates opiate analgesia - an example of nutrient/pharmaceutical up-regulation of the endogenous analgesia system

In the author's clinical experience, concurrent treatment with DL-phenylalanine (DLPA) often appears to potentiate pain relief and also ease depression in patients receiving opiates for chronic non-malignant pain. An analysis of this phenomenon suggests that it may be mediated, at least in part, by up-regulation of the 'endogenous analgesia system' (EAS), a neural pathway that projects caudally from medullary nuclei to the dorsal horn of the spinal column; when stimulated by chronic pain or therapeutic measures such as opiates or acupuncture, the EAS suppresses activation of second-order pain-receptive neurons in the dorsal horn, and thereby alleviates pain. Since serotonin and enkephalins are key neurotransmitters in the EAS, it is reasonable to predict that measures which promote serotonin activity (such as 5-hydroxytryptophan and serotonin-reuptake inhibitors) as well as enkephalin activity (such as D-phenylalanine, an enkephalinase inhibitor) should potentiate EAS-mediated analgesia - a view consistent with much previous medical research. Comprehensive support of the EAS with well-tolerated nutrients and pharmaceuticals may amplify the analgesic efficacy of chronic opiate therapy, while enabling dosage reductions that minimize opiate side-effects. Analogously, this approach may complement the efficacy of acupuncture and other analgesic measures that activate the EAS.

A meta-analysis of fibromyalgia treatment interventions

OBJECTIVE

To evaluate and compare the efficacy of pharmacological and nonpharmacological treatments of fibromyalgia syndrome (FMS).

METHODS

This meta-analysis of 49 fibromyalgia treatment outcome studies assessed the efficacy of pharmacological and nonpharmacological treatment across four types of outcome measures-physical status, self-report of FMS symptoms, psychological status, and daily functioning.

RESULTS

After controlling for study design, antidepressants resulted in improvements on physical status and self-report of FMS symptoms. All nonpharmacological treatments were associated with significant improvements in all four categories of outcome measures with the exception that physically-based treatment (primarily exercise) did not significantly improve daily functioning. When compared, nonpharmacological treatment appears to be more efficacious in improving self-report of FMS symptoms than pharmacological treatment alone. A similar trend was suggested for functional measures.

CONCLUSION

The optimal intervention for FMS would include nonpharmacological treatments, specifically exercise and cognitive-behavioral therapy, in addition to appropriate medication management as needed for sleep and pain symptoms.

Hypothalamic-pituitary-adrenal axis perturbations in patients with fibromyalgia

OBJECTIVE

To examine basal and stimulated hypothalamic-pituitary-adrenal (HPA) axis and related hormone levels, including adrenocorticotropin (ACTH), cortisol, arginine vasopressin (AVP), and neuropeptide Y (NPY), in patients with fibromyalgia (FM).

METHODS

Basal and ovine corticotropin-releasing hormone (oCRH)-stimulated HPA axis function were assessed in 12 patients with FM and in age- and sex-matched normal subjects. Basal plasma AVP levels and AVP release after postural change were assessed, and plasma NPY levels were measured in the same samples.

RESULTS

Patients with FM had low 24-hour urinary free cortisol, but normal peak and elevated trough plasma cortisol levels, compared with normal subjects. The net integrated ACTH response to oCRH in FM was not significantly different from that in normal subjects, but tended toward an exaggerated response. There was a significant decrease in net integrated cortisol response to oCRH in FM patients, indicating adrenal hyporesponsiveness. AVP levels were not significantly different between FM patients and control subjects, but variability was greater among the FM patients. Plasma NPY levels were significantly lower in FM patients than in normal subjects.

CONCLUSION

These data support the view that HPA axis function is perturbed in patients with FM. Further study is required to ascertain the cause of HPA axis perturbations and their relationship to symptoms in patients with FM.

A double-blind crossover study of two cyclobenzaprine regimens in primary fibromyalgia syndrome

In a double-blind crossover study, the efficacy and tolerability of oral cyclobenzaprine administered in two different regimens were compared in 40 patients affected by primary fibromyalgia syndrome. The patients were randomly divided into two groups. Each group of 20 patients was treated for 15 days with either a single dose of 10 mg/day cyclobenzaprine at bedtime or 30 mg/day cyclobenzaprine in three equal doses daily. Following treatment there was a 15-day washout period before the groups were crossed over to the other treatment. Both regimens resulted in a significant decline in the number of tender points; significant improvements were also reported in the quality of sleep, anxiety, fatigue, irritable bowel syndrome and stiffness. There was no significant difference in efficacy between the two therapeutic regimens at any stage during the trial. The frequency of reported side-effects was significantly greater (P < 0.001) when patients received 30 mg/day cyclobenzaprine (26 patients, 84%) than when they received 10 mg/day (10 patients, 27%). A dose of 10 mg cyclobenzaprine at bedtime significantly improved the symptomatology of patients affected by primary fibromyalgia syndrome. The higher dose did not further reduce these symptoms but did result in a higher incidence of side-effects.