Diet drugs and cardiac valvulopathy: a survey of dental patients

The recent finding that several appetite suppressant drugs (fenfluramine and dexfenfluramine) were linked to cardiac valvular disease in a significant percentage of the population led to their voluntary withdrawal. The Centers for Disease Control and Prevention issued a series of recommendations in 1997 for evaluating dental patients who had taken these drugs. Since that time, several studies have further investigated the prevalence of valvular abnormalities. This information is crucial because of the problem of dentally associated bacterial endocarditis. This study surveyed more than 1,300 dental patients and determined the prevalence of patients taking these diet drugs and cardiac valvulopathy and the percentage of dental patients required to take antimicrobial endocarditis prophylaxis before "at risk" dental procedures. It remains important for dentists to query their patients for this information.

An exploratory approach to the serotonin syndrome: an update of clinical phenomenology and revised diagnostic criteria

Serotonin-related adverse side-effects of psychotropic drugs were first recorded in humans in 1960. However, since 1991, these related cases have been diagnosed as 'serotonin syndrome (SS)' according to the criteria reported by Sternbach. In this article, we have reviewed and further explored the validity of these criteria. The clinical profile of 24 cases of the SS published between 1991 and 1995 has been analysed in detail and compared with the symptomatology of 38 previous cases which were also further analysed. Mainly Medline and references from other reports were used to review these cases. The general concept put forward by Sternbach has been approved. On the basis of the severity of overall clinical presentation, it appeared that there is a need to further classify SS into three main groups as: (1) mild state of serotonin-related symptoms; (2) serotonin syndrome (full-blown form); (3) toxic states. Furthermore, the detailed analysis of the SS cases published so far suggests that 'the diagnostic criteria for SS' also require further revision, and these are presented here. We also review, present and discuss the guidelines for the management and treatment of SS.

Dexfenfluramine for weight gain secondary to psychotropics

We describe the use of dexfenfluramine (Redux) in six patients with mood disorders (bipolar disorder = 3; major depression = 3) who developed significant weight gain as a result of their psychotropics. All patients were females with an age range of 27-58 years. The duration of the trial varied from 3 to 20 weeks, with the dexfenfluramine dosage being 15 mg twice daily. Weight loss ranged from 2 to 23 pounds. None of the patients had any evidence of primary pulmonary hypertension or serotonin syndrome, despite being on serotonergic agents such as fluoxetine, paroxetine, and sertraline.

Sexual side effects of antidepressant drugs

Sexual functioning often suffers during depression, although depressed people continue to value sex. Many popular antidepressants further impair sexual functioning, with highly serotonergic agents affecting orgasm and libido prominently. This paper addresses clinical assessment of sexual side effects from antidepressant drugs and reviews treatment strategies, including purported antidotes. We pay particular attention to sildenafil, on which there are impressive data and ongoing controlled studies.

Valvular abnormalities and cardiovascular status following exposure to dexfenfluramine or phentermine/fenfluramine

CONTEXT

Fenfluramine and dexfenfluramine were voluntarily withdrawn from the market in September 1997 because of reports of an association with heart valve abnormalities. Studies have been limited by lack of comparison with untreated controls.

OBJECTIVE

To evaluate cardiovascular status and the prevalence of valvular abnormalities, as assessed by clinical cardiovascular parameters and echocardiography, in patients treated for obesity with dexfenfluramine or phentermine/fenfluramine.

DESIGN

Reader-blinded controlled study completed in February 1998.

SETTING AND PARTICIPANTS

Twenty-five clinical centers in the United States. Of 1640 enrolled subjects, 1473 were eligible (479 and 455 had taken dexfenfluramine and phentermine/fenfluramine, respectively, continuously for 30 days or more in the previous 14 months, and 539 were untreated matched controls) and provided clinical and echocardiographic data. Mean (SD) age was 47.4 (11.4) years, mean body mass index was 35.0 (7.4) kg/m2, and 74% were women. Mean (SD) duration of therapy was 6.0 (3.3) months (range, 1-18.4 months) in the dexfenfluramine group, and 11.9 (10.4) months (range, 1.4-63 months) in the phentermine/fenfluramine group, while the untreated group had no anorexigen use during the previous 5 years.

MAIN OUTCOME MEASURES

Cardiovascular signs and symptoms; echocardiographic evidence of aortic (AR) or mitral (MR) regurgitation according to US Food and Drug Administration (FDA) criteria (AR > or = mild or MR > or = moderate) and by grade; tricuspid and pulmonic valve regurgitation; and aortic, mitral, and tricuspid valve leaflet mobility and thickness, for treated vs untreated subjects.

RESULTS

Cardiovascular signs and symptoms were similar among anorexigen-treated and untreated subjects. Prevalence rates and relative risk (RR) of AR were significantly increased in anorexigen-treated patients and were 8.9% in the dexfenfluramine group (RR, 2.18; 95% confidence interval [CI], 1.32-3.59), 13.7% in the phentermine/fenfluramine group (RR, 3.34; 95% CI, 2.09-5.35), and 4.1% in the untreated group (P<.001). No statistically significant differences in prevalence were observed for MR, thickening or decreased mobility of any valve leaflet, calculated pulmonary artery systolic pressure, or left ventricular ejection fraction. Serious cardiac events (including myocardial infarction, congestive heart failure, or ventricular arrhythmia) occurring at any time were not statistically different in treated and untreated subjects (dexfenfluramine, 9.0%; phentermine/fenfluramine, 4.0%; and untreated, 8.4%); and following anorexigen treatment were uncommon (dexfenfluramine, 2.3%; phentermine/fenfluramine, 2.4%, and untreated, 3.3%, when adjusted for the median start date of anorexigen use).

CONCLUSIONS

Our data indicate that use of dexfenfluramine and phentermine/fenfluramine is associated with an increase in the prevalence of AR using FDA echocardiographic criteria, but was not associated with an increase in the prevalence of MR using FDA criteria or with serious cardiac events.

Long term psychiatric and cognitive effects of MDMA use

Clinical case reports suggest that regular MDMA use can be associated with chronic psychiatric symptoms which persist after the cessation of drug use. Neuropsychological comparisons of regular MDMA users and controls also suggest that MDMA use may lead to memory deficits, with other cognitive processes relatively unaffected. This paper reviews these studies and discusses a number of methodological issues that impact on the interpretation of the findings. Methods for examining the biological effects of MDMA use in man are also outlined. Future research should clarify whether MDMA use has long term psychological effects, and if these are related to changes in central serotonergic function.

Toxicity of drug abuse--amphetamine designer drugs (ecstasy): mental effects and consequences of single dose use

MDMA (3,4-methylendioxymethamphetamine) is the most commonly used substance within the 'ecstasy' group of drugs. MDMA interferes with serotonin and catecholamine transporters in the central nervous system to increase monoamine synaptic levels and thereby mediate the majority of its central nervous effects. These range from wanted effects like euphoria, central nervous stimulation, and feeling of closeness to mild hallucinations, impairment of cognition and co-ordination and further to serious reactions like agitation, disturbed and bizarre behaviour, and possibly psychosis. The full picture of the consequences of these transitory changes is not known. It has been assumed that the risk of being involved in fatalities and accidents during the state of MDMA influence is increased, but this possible risk increase has so far not been determined. Observations of the prevalence of MDMA involvement in cases of reckless driving and the MDMA blood concentrations measured indicate a risk increase comparable to that observed after use of amphetamines.

Effect of ecstasy [3,4-methylenedioxymethamphetamine (MDMA)] on cerebral blood flow: a co-registered SPECT and MRI study

3,4-methylenedioxymethamphetamine (MDMA), an illicit recreational drug, damages serotonergic nerve endings. Since the cerebrovasculature is regulated partly by the serotonergic system, MDMA may affect cerebral blood flow (CBF) in humans. We evaluated 21 abstinent recreational MDMA users and 21 age- and gender-matched healthy subjects with brain SPECT and MRI. Ten of the MDMA subjects also had repeat SPECT and MRI after receiving two doses of MDMA. Abstinent MDMA users showed no significantly different global or regional CBF (rCBF) compared to the control subjects. However, within 3 weeks after MDMA administration, rCBF remained decreased in the visual cortex, the caudate, the superior parietal and dorsolateral frontal regions compared to baseline rCBF. The decreased rCBF tended to be more pronounced in subjects who received the higher dosage of MDMA. Two subjects who were scanned at 2-3 months after MDMA administration showed increased rather than decreased rCBF. Low-dose recreational MDMA use does not cause detectable persistent rCBF changes in humans. The lack of long-term rCBF changes may be due to a non-significant effect of serotonergic deficits on rCBF, or regeneration of serotonergic nerve terminals. The subacute decrease in rCBF after MDMA administration may be due to the direct effect of MDMA on the serotonergic system or the indirect effects of its metabolites on the dopaminergic system; the preliminary data suggest these effects may be transient.

Possible role of valvular serotonin 5-HT(2B) receptors in the cardiopathy associated with fenfluramine

Dexfenfluramine was approved in the United States for long-term use as an appetite suppressant until it was reported to be associated with valvular heart disease. The valvular changes (myofibroblast proliferation) are histopathologically indistinguishable from those observed in carcinoid disease or after long-term exposure to 5-hydroxytryptamine (5-HT)(2)-preferring ergot drugs (ergotamine, methysergide). 5-HT(2) receptor stimulation is known to cause fibroblast mitogenesis, which could contribute to this lesion. To elucidate the mechanism of "fen-phen"-associated valvular lesions, we examined the interaction of fenfluramine and its metabolite norfenfluramine with 5-HT(2) receptor subtypes and examined the expression of these receptors in human and porcine heart valves. Fenfluramine binds weakly to 5-HT(2A), 5-HT(2B), and 5-HT(2C) receptors. In contrast, norfenfluramine exhibited high affinity for 5-HT(2B) and 5-HT(2C) receptors and more moderate affinity for 5-HT(2A) receptors. In cells expressing recombinant 5-HT(2B) receptors, norfenfluramine potently stimulated the hydrolysis of inositol phosphates, increased intracellular Ca(2+), and activated the mitogen-activated protein kinase cascade, the latter of which has been linked to mitogenic actions of the 5-HT(2B) receptor. The level of 5-HT(2B) and 5-HT(2A) receptor transcripts in heart valves was at least 300-fold higher than the levels of 5-HT(2C) receptor transcript, which were barely detectable. We propose that preferential stimulation of valvular 5-HT(2B) receptors by norfenfluramine, ergot drugs, or 5-HT released from carcinoid tumors (with or without accompanying 5-HT(2A) receptor activation) may contribute to valvular fibroplasia in humans.

Consumption and dangers of ecstasy: an amphetamine derivative with a misleading reputation of safety

(1) Ecstasy carries a risk of potentially severe short-term complications, even after occasional ingestion of low doses. The risk has not been assessed thoroughly, however, and long-term toxicity is even less well established.

[Neuropsychiatric disorders induced by MDMA ("Ecstasy")]

If neurotoxicity of MDMA (ecstasy) is now well documented in animals, it is not the same in humans. MDMA intoxication puts the problem of its possible link with the serotonin syndrome and the neuroleptic malignant syndrome. Neuropathological consequences following MDMA intake have been reported, including hemorrhaging and cerebral infarction, cerebral venous sinus thrombosis, and acute inflammatory CNS disease. However, the physiopathology of these complications remains unclear. In the same way, there have been various reports that have attributed MDMA to precipitating the onset of a wide range of psychiatric disorders including sleep disorders, cognitive disorders, panic attacks, depression, flashbacks, psychosis and severe paranoia. Findings suggest that these psychiatric manifestations might be consequences of MDMA induced brain serotonin neurotoxic lesions. All these data are examined from a critical review of the literature.

[Appetite suppressants and heart valve disorders]

Serotoninergic appetite-suppressant drugs, fenfluramine and dexfenfluramine, were withdrawn from the market in September 1997 on account of two major cardiopulmonary complications: primary pulmonary hypertension and valvular regurgitation. The valvular heart diseases involve mainly left-sided valves, and contrary to physiological valvular regurgitations, they appear mostly on the aortic valve. Prolonged exposure (> 3 months) appears to confer a higher risk of cardiac valve involvement. Pathological features are similar to carcinoid or ergot alkaloid-induced valve diseases, and suggest a common pathophysiological mechanism which would also explain pulmonary hypertension by the toxic effect of high levels of circulating serotonin. After the first reports documenting a dramatically high prevalence of valvular side effects (up to 33% according to the Food and Drug Administration), recent studies reported a lower prevalence and severity. The long-term outcome and the real incidence are unknown and require further research and epidemiological data. A clinical survey of the patients exposed to serotoninergic appetite-suppressants is necessary, to be repeated 6 to 8 months later in the absence of an initial cardiac murmur. Doppler echocardiographic examination should be performed after prolonged exposure (> 3 months) or a high dosage of these drugs, in circumstances such as the presence of cardiovascular symptoms, a cardiac murmur, or an uncertain cardiac examination because of weight of patients.

Serotonin receptor physiology: relation to emesis

Several serotonin (5-HT) receptor subtypes have been defined by pharmacological responses to selective agonists and antagonists and by pathways of receptor-effector coupling. Using molecular techniques, additional receptor subtypes have been described. 5-HT receptors are prevalent in the central nervous system and gut and participate in induction of emesis. 5-HT3 antagonists are used to prevent emesis from cancer chemotherapy and also demonstrate efficacy in radiation-induced nausea, postoperative nausea, hyperemesis gravidarum, and nausea and vomiting with the acquired immunodeficiency syndrome. 5-HT4 agonists exhibit prokinetic properties in nauseated patients with gastroparesis and functional dyspepsia. Conversely, 5-HT4 antagonists have antiemetic activity in some experimental models. The 5-HT1D receptor agonist sumatriptan reduces emesis with migraine headaches and in cyclic vomiting syndrome, most likely via action on central nervous system sites. In other models, 5-HT1A and 5-HT2A/5-HT2C agonists exhibit antiemetic properties. The utility of 5-HT receptor ligands in treating emesis is the subject of active investigation.

Reduced in vivo binding to the serotonin transporter in the cerebral cortex of MDMA ('ecstasy') users

BACKGROUND

The use of MDMA ('ecstasy') is common among young people in Western countries. Animal models of MDMA toxicity suggest a loss of serotonergic neurons, and potentially implicate in the development of significant psychiatric morbidity in humans.

AIMS

To test whether long-term use of MDMA can produce abnormalities in cerebral serotonin, but not dopamine, transporter binding measured by single photon emission computed tomography (SPECT).

METHOD

Ten male regular ecstasy users and 10 well-matched controls recruited from the same community sources participated in SPECT with the serotonin transporter (SERT) ligand [123I] beta-CIT. Dopamine transporter binding was determined from scans acquired 23 hours after injection of the tracer.

RESULTS

Ecstasy users showed a cortical reduction of SERT binding, particularly prominent in primary sensory-motor cortex, with normal dopamine transporter binding in lenticular nuclei.

CONCLUSIONS

This cross-sectional association study provides suggestive evidence for specific, at least temporary, serotonergic neurotoxicity of MDMA in humans.

A placebo-controlled clinical trial of L-tryptophan in premenstrual dysphoria

BACKGROUND

Antidepressant drugs, including specific serotonin reuptake inhibitors, have been shown to be beneficial in the treatment of premenstrual dysphoric disorders. The present study tests the efficacy of L-tryptophan, which acts specifically on serotonergic neurons, in this disorder.

METHODS

In a randomized controlled clinical trial, 37 patients with premenstrual dysphoric disorder were treated with L-tryptophan 6 g per day, and 34 were given placebo. The treatments were administered under double-blind conditions for 17 days, from the time of ovulation to the third day of menstruation, during three consecutive menstrual cycles.

RESULTS

The Visual Analogue Scales (VAS) revealed a significant (p = .004) therapeutic effect of L-tryptophan relative to placebo for the cluster of mood symptoms comprising the items of dysphoria, mood swings, tension, and irritability. The magnitude of the reduction from baseline in maximum luteal phase VAS-mood scores was 34.5% with L-tryptophan compared to 10.4% with placebo.

CONCLUSIONS

These results suggest that increasing serotonin synthesis during the late luteal phase of the menstrual cycle has a beneficial effect in patients with premenstrual dysphoric disorder.

Positron emission tomographic evidence of toxic effect of MDMA ("Ecstasy") on brain serotonin neurons in human beings

BACKGROUND

(+/-)3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") is a popular recreational drug that selectively damages brain serotonin (5-HT) neurons in animals at doses that closely approach those used by humans. We investigated the status of brain 5-HT neurons in MDMA users.

METHODS

We enrolled 14 previous users of MDMA who were currently abstaining from use and 15 controls who had never used MDMA. We used positron emission tomography (PET) with the radioligand carbon-11-labelled McN-5652, which selectively labels the 5-HT transporter. We analysed whether there were differences in 5-HT transporter binding between abstinent MDMA users and participants in the control group. Blood and urine samples were taken and tested to check for abstinence.

FINDINGS

MDMA users showed decreased global and regional brain 5-HT transporter binding compared with controls. Decreases in 5-HT transporter binding positively correlated with the extent of previous MDMA use.

INTERPRETATION

Quantitative PET studies with a ligand selective for 5-HT transporters can be used to assess the status of 5-HT neurons in the living human brain. We show direct evidence of a decrease in a structural component of brain 5-HT neurons in human MDMA users.

Methysergide

Methysergide is a semisynthetic ergot alkaloid ergometrine derivative, introduced in pharmacotherapy for migraine prophylaxis as a specific serotonin (5HT) receptor antagonist. Methysergide is not just a 5HT2 antagonist, it is also a 5HT1 agonist. Open and controlled studies attest to methysergide's efficacy. It may be more effective in resistant cases with a high attack frequency and may act synergistically with ergotamine and dihydroergotamine (DHE) for breakthrough attacks. Contraindications include pregnancy, peripheral vascular disorders, severe arteriosclerosis, coronary artery disease, severe hypertension, thrombophlebitis or cellulitis of the legs, peptic ulcer disease, fibrotic disorders, lung diseases, collagen disease, liver or renal function impairment, valvular heart disease, debilitation, or serious infection. Methysergide can induce retroperitoneal fibrosis and pleural and heart valve fibrosis with an estimated incidence of 1 in 5,000 treated patients. Therefore, it should be reserved for severe cases in which other migraine preventive drugs are not effective.

Update on the pharmacotherapy of obesity

OBJECTIVE

To review recent developments in the pharmacotherapy of obesity, including the agents currently approved for use in the management of obesity and those under development.

DATA SOURCES

A MEDLINE search from January 1990 to July 1997 was conducted to identify English literature available on the pharmacotherapy of obesity. The search was supplemented by a review of the bibliographies of identified literature.

STUDY SELECTION

All controlled and uncontrolled trials were reviewed. When available, double-blind, placebo-controlled trials were used preferentially.

DATA EXTRACTION

Agents were reviewed with regard to mechanism of action, clinical trial data regarding efficacy, adverse effects, pharmacokinetics, drug interactions, and contraindications where information was available. Study design, selected population, results, and adverse effect information were included.

DATA SYNTHESIS

The anorexiants currently available or under development for the management of obesity regulate food intake and satiety via the adrenergic and/or serotonergic pathways. Clinical trials have shown a 10-15% weight loss can typically be anticipated; however, little long-term safety and efficacy data are available. Adverse events tend to be mild and self-limiting, but serious adverse events can occur. Treatment options under development include thermogenic agents, digestive inhibitors, and analogs and antagonists of hormones that regulate food intake and satiety.

CONCLUSIONS

Several mechanisms to control weight are currently under investigation for the management of obesity. Since obesity is a chronic condition, further studies should be conducted to evaluate the long-term safety and efficacy of these agents and the role of combination therapy using different modalities.

Serotonin, dopamine, and motor effects in Parkinson's disease

We review recent reports suggesting that use of selective serotonergic agents that either inhibit synaptic reuptake or have specific serotonin receptor affinities may benefit a variety of motor disturbances in Parkinson's disease. The complex, mixed motoric effects of these agents in Parkinson's disease have not allowed for a consistent view on the interrelationship between dopamine and serotonin (5HT) in motor control but may speak to the nature of dysregulated neurotransmission in the disease.

The serotonin syndrome

The serotonin syndrome is characterized by mental status changes and a variety of autonomic and neuromuscular manifestations. Its duration is usually brief, resolving within hours provided that the inciting agent has been discontinued. In most cases, two or more types of medications known to increase the activity of serotonin at the 5-HT1A receptor are required to produce it, and it frequently begins soon after the initiation of a new treatment regimen. Treatment is largely supportive although limited clinical experience warrants the cautious use of specified agents. Although its overall incidence is unknown, it is probably low, and an appropriate level of suspicion coupled with an adequate knowledge of the patient's drug history remains the mainstay of diagnosis and treatment.

Hormonal response during a fenfluramine-associated panic attack

Secretion curves for prolactin, cortisol, TSH, and GH from a 37-year old woman with dysthymia and panic disorder with agoraphobia were determined one day prior to (day I), and during a panic attack (day II) associated with an oral dose of 60 mg dl-fenfluramine, a drug known to increase anticipatory anxiety. The increased cortisol secretion observed is discussed in relation to the hormonal correlates of anxiety and the possible role of depression, dl-fenfluramine, and serotonergic receptor sensitivity.

Serotonin syndrome

Serotonin syndrome usually occurs after treatment with monoamine oxydase inhibitors and drugs that enhance serotoninergic transmission. Serotonin agents, such as Proza, are commonly prescribed drugs; therefore, the serotonin syndrome appears more frequently than before. Clinicians must be able to prevent, recognize, and treat this syndrome in their practice. This review summarizes the literature of case reports of patients who developed the serotonin syndrome.

Serotonergic receptors as targets for pharmacotherapy

Knowledge about neurotransmitters, their receptors and their physiological effects has exploded in the past 15-20 years. Serotonin exerts diverse effects as a neurotransmitter and in nonneural tissues. The molecular sites of serotonin binding, re-uptake and autoregulation have proven to be viable targets for pharmacological intervention in a variety of disorders.

The serotonin syndrome and psychosis-like side-effects of fluvoxamine clinical use--an estimation of incidence

OBJECTIVE

The incidence of the serotonin syndrome or serotonin-syndrome-like side effects during treatment with the selective serotonin reuptake inhibitor (SSRI) fluvoxamine should be evaluated.

METHOD

200 inpatients treated for the first time with fluvoxamine were prospectively evaluated for the occurrence of a serotonin syndrome over a period of 8200 treatment days. Retrospective follow-up data of outpatient treatment covered 8891 days.

RESULTS

No full-blown serotonin syndrome occurred, but 3 patients developed a reversible change of mental status with insomnia, agitation, confusion and incoherent thoughts without other symptoms of the serotonin syndrome.

CONCLUSIONS

It is concluded that the occurrence of a potentially lethal serotonin syndrome is rare in fluvoxamine treatment psychosis-like syndromes as a side effect of serotonergic stimulation might occur. In the investigated sample the rate was 0.006-0.04 per 100 treatment days.