The role of systematic reviews in pharmacovigilance planning and Clinical Trials Authorisation application: example from the SLEEPS trial

BACKGROUND

Adequate sedation is crucial to the management of children requiring assisted ventilation on Paediatric Intensive Care Units (PICU). The evidence-base of randomised controlled trials (RCTs) in this area is small and a trial was planned to compare midazolam and clonidine, two sedatives widely used within PICUs neither of which being licensed for that use. The application to obtain a Clinical Trials Authorisation from the Medicines and Healthcare products Regulatory Agency (MHRA) required a dossier summarising the safety profiles of each drug and the pharmacovigilance plan for the trial needed to be determined by this information. A systematic review was undertaken to identify reports relating to the safety of each drug.

METHODOLOGY/PRINCIPAL FINDINGS

The Summary of Product Characteristics (SmPC) were obtained for each sedative. The MHRA were requested to provide reports relating to the use of each drug as a sedative in children under the age of 16. Medline was searched to identify RCTs, controlled clinical trials, observational studies, case reports and series. 288 abstracts were identified for midazolam and 16 for clonidine with full texts obtained for 80 and 6 articles respectively. Thirty-three studies provided data for midazolam and two for clonidine. The majority of data has come from observational studies and case reports. The MHRA provided details of 10 and 3 reports of suspected adverse drug reactions.

CONCLUSIONS/SIGNIFICANCE

No adverse reactions were identified in addition to those specified within the SmPC for the licensed use of the drugs. Based on this information and the wide spread use of both sedatives in routine practice the pharmacovigilance plan was restricted to adverse reactions. The Clinical Trials Authorisation was granted based on the data presented in the SmPC and the pharmacovigilance plan within the clinical trial protocol restricting collection and reporting to adverse reactions.

[Similarity of cycloprolylglycine to piracetam in antihypoxic and neuroprotective effects]

The antihypoxic activity of the endogenous cyclic dipeptide cycloprolylglycine (CPG) has been studied on a model of normobaric hypoxia with hypercapnia and its neuroprotective activity has been studied on a model of human neuroblastoma SH-SY5Y cell damage by 6-hydroxydopamine. It is established that CPG exhibits the antihypoxic activity at doses of 0.5 and 1.0 mg/kg (i.p.) on outbred and BALB/c mice, but not on C57B1/6 mice. The neuroprotective activity of CPG was detected in 10(-5) - 10(-8) M concentration range only when the treatment was carried out 24h before toxin introduction. The obtained data confirm the hypothesis that piracetam is a mimetic of the endogenous CPG neuropeptide.

Systemic therapy for primary hyperhidrosis: a retrospective study of 59 patients treated with glycopyrrolate or clonidine

BACKGROUND

Data regarding systemic medications in the management of hyperhidrosis (HH) are limited.

OBJECTIVE

The goal of this study was to provide evidence for the safety and efficacy of systemic medications for primary HH.

METHODS

A retrospective chart review was conducted of patients seen at an academic dermatology department prescribed systemic medications for primary HH.

RESULTS

A total of 71 patients were prescribed systemic agents. Twelve patients (17%) were lost to follow-up and were excluded from further analysis. A total of 59 patients with at least 2 months of follow-up data (mean age 28.9 ± 12.0 years; 37 women, 22 men; mean follow-up 19.5 months) were included in the analysis. Palmoplantar and/or axillary HH was most common (42/59; 71%); followed by generalized (9/59; 15%) and craniofacial (8/59; 14%) HH. Glycopyrrolate (generally 1-2 mg once or twice daily) was prescribed to 45 patients, with response rate of 67% (30/45). Fifteen treatment failures included 6 nonresponders and 9 with adverse effects, including xerostomia and gastrointestinal disturbance. Clonidine (0.1 mg twice daily) was prescribed to 13 patients, with a response rate of 46% (6/13). Seven treatment failures included 3 nonresponders and 4 with adverse effects, all relating to decreased blood pressure. One patient responded to oxybutynin at 5 mg twice daily. There were no significant differences in efficacy (P = .21; odds ratios 0.43, 95% confidence interval 0.12-1.5) or adverse effects (P = .46; odds ratios 1.78, 95% confidence interval 0.44-7.1) in comparing glycopyrrolate versus clonidine.

LIMITATIONS

This was a retrospective study from a single, university-based population.

CONCLUSION

Systemic therapy with glycopyrrolate or clonidine can be effective for HH. Nearly two-thirds responded to therapy, and less than a quarter had treatment-limiting adverse effects, all of which were self-limited and nonserious.

Requirement of intact sympathetic transmission for the ocular hypotensive effects of melatonin and 5-MCA-NAT

Melatonin and its analogue, 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT), potently reduce intraocular pressure, and may be good candidates for the treatment of ocular hypertension and glaucoma. After chemical sympathectomy by reserpine or 6-hydroxydopamine, the hypotensive effects of melatonin and 5-MCA-NAT are severely inhibited. This indicates that the sympathetic nervous system is involved in the production and drainage of aqueous humour by the ciliary body and trabecular meshwork, and that it mediates the effects of melatonin and its analogue, 5-MCA-NAT.

Pharmacologic reduction of CNS noradrenergic activity in PTSD: the case for clonidine and prazosin

This article reviews the neurobiologic rationale for and presents clinical guidance concerning the use of medications that reduce central nervous system noradrenergic activity in the treatment of intrusive symptoms of posttraumatic stress disorder. The authors reviewed neurobiological studies, nonclinical studies using animal models, clinical case reports, open-label drug studies, and blinded, placebo-controlled drug studies. This review of the basic science and clinical literature, and the authors' clinical experience with culturally and demographically diverse populations, indicate that clonidine and prazosin can play a useful role in treating sleep disturbance and hyperarousal in posttraumatic stress disorder, with minimal adverse effects and low financial cost.

Role of amygdalo-nigral circuitry in conditioning of a visual stimulus paired with food

The amygdala central nucleus (CeA) plays an important part in associative learning. Although most research has focused on functions of its descending projections to brainstem areas involved in autonomic and somatomotor responses, the ascending projections of CeA also play critical roles in learning. For example, a CeA-nigrostriatal pathway is important for acquiring orienting responses (ORs) to conditioned stimuli (CSs) that signal food delivery. In this study, the function of this CeA-nigrostriatal pathway in appetitive conditioning of rats was considered in more detail. In experiment 1, we combined anatomical tracing and methods for detecting neuronal activation to examine whether CeA neurons that project to the substantia nigra pars compacta (SNc) are activated by a visual CS for food. After injection of the retrograde tracer Fluoro-Gold (FG) into SNc, the rats received pairings of a visual CS with food. After a test with the CS alone, the brains were prepared to assess FG labeling and CS-induced Fos expression in CeA with immunohistochemical procedures. Colocalization of Fos and FG in CeA neurons was visualized with confocal-fluorescence microscopy. The CS induced Fos expression in CeA, and a majority of these Fos-positive neurons were also FG positive, indicating activation of the CeA-SNc pathway by the CS. In experiment 2, lesions that disconnected CeA and SNc prevented the acquisition of conditioned ORs but did not affect the acquisition of conditioned food-related responses or the display of unconditioned ORs. These experiments demonstrate a role for amygdalo-nigral circuitry in learned modulation of attention to signals for biologically significant events.

The Comparative Effects of Remifentanil or Magnesium Sulfate Versus Placebo on Attenuating the Hemodynamic Responses After Electroconvulsive Therapy

In this prospective, randomized, double-blind, placebo-controlled, crossover study we compared the effects of remifentanil or magnesium sulfate (MgSO4) versus placebo in attenuating the sympathetic response to electroconvulsive therapy. Twenty adults underwent a total of 115 anesthetics for therapeutic electroconvulsive therapy. Patients were randomly allocated twice into each of the three test groups: placebo control, MgSO4 30 mg/kg, or remifentanil 1.0 microg/kg. Systolic and diastolic arterial blood pressures, heart rate, and oxygen saturations were recorded before IV access was established. Anesthesia was induced with thiopental 4 mg/kg. The trial drug was then administered and neuromuscular blockade was followed with succinylcholine 0.5 mg/kg before electroconvulsive therapy was performed. All measurements were repeated at 0, 1, 3 and 10 min after the seizure ended. Remifentanil and MgSO4 produced a statistically significant attenuation of the increase in systolic arterial blood pressure at 0, 1, and 3 min (P < 0.05). Remifentanil, but not MgSO4 or placebo, attenuated the increase in heart rate at 1 and 3 min but not the peak rate. Remifentanil increased the duration of apnea (mean 90 s), with no other adverse respiratory effects. Mean seizure duration time was 33 (+/- 14) s, with no difference among the groups. In conclusion, remifentanil 1.0 microg/kg and MgSO4 30 mg/kg attenuated the systolic arterial blood pressure response to electroconvulsive therapy without reducing the duration of seizure activity. Because MgSO4 has less effect on HR, it might offer advantages over remifentanil in patients at risk for post-electroconvulsive therapy bradycardia.

Effects of systemically applied clonidine on intestinal perfusion and oxygenation in healthy pigs during general anaesthesia and laparotomy 1

BACKGROUND AND OBJECTIVE

Clonidine, which is used for induction of sympatholysis and prevention or treatment of alcohol withdrawal in anaesthesia and intensive care medicine, may have deleterious effects on intestinal mucosal perfusion. This study was designed to investigate the effects of clonidine on intestinal perfusion and oxygenation.

METHODS

Following ethical approval 17 anaesthetized, and acutely instrumented pigs were randomly assigned to two groups: eight animals received intravenous clonidine (2 microg kg(-1) bolus and 2 microg kg(-1) h(-1)), nine animals served as a control group. Measurement points for systemic and regional haemodynamic and oxygenation parameters were 135 and 315 min after starting the clonidine application.

RESULTS

Clonidine elicited systemic haemodynamic changes (median [25-75th interquartile range]): heart rate (106 [91, 126] to 84 [71, 90] beats min(-1)) cardiac output (147 [123, 193] to 90 [87, 107] mL min(-1) kg(-1)) and mean arterial pressure (77 [72, 93] to 69 [61, 78] mmHg) decreased. Despite systemic haemodynamic changes, the superior mesenteric artery blood flow did not change in the clonidine group. The vascular resistance of the superior mesenteric artery decreased. The small intestinal oxygen supply, the mucosal and the serosal tissue oxygen partial pressure did not change.

CONCLUSIONS

Systemic sympatholysis induced by intravenously applied clonidine in addition to basic intravenous anaesthesia elicited a decrease in cardiac output and mean arterial pressure. However, regional macrohaemodynamic perfusion was maintained and intestinal oxygenation did not change. Clonidine does not impair intestinal mucosal and serosal oxygenation under physiological conditions.

The data monitoring experience in the MOXCON trial

AIMS

This article describes a challenging data monitoring experience that occurred in a major international randomized placebo-controlled trial in patients with heart failure, in which the accumulating interim data showed an excess of deaths on the active treatment.

METHODS AND RESULTS

The MOXonidine CONgestive Heart Failure trial was a randomized comparison of moxonidine, a central sympathetic inhibitor, with placebo. It was planned to recruit 4500 patients with heart failure. The primary endpoint was all-cause mortality, and average follow-up was anticipated to be around 2.5 years until 724 deaths occurred. The trial Data Monitoring Board (DMB) was to conduct safety monitoring reviews of interim data at least every six months, and make their recommendations to the Executive Committee. Within a few months of the study starting, the Data Monitoring Board (DMB) observed an emerging trend of an excess of deaths on moxonidine compared with placebo. This article describes the sequence of events that unfolded: several DMB meetings to evaluate the accumulating evidence, a DMB recommendation to stop the trial, consequent dialogue with the Executive Committee and sponsor leading to a final decision to stop the trial. Ten months after the first patient was randomized, the study was stopped based on 46 versus 25 deaths in 990 moxonidine and 943 placebo patients, respectively, P=0.01. The final published evidence had 54 versus 32 deaths, P=0.012.

CONCLUSIONS

This study illustrates the problems faced by a DMB, and subsequently the trial Executive Committee and sponsor, in deciding how to act in the face of an emerging (and agonizing) negative trend for mortality in a major international trial.

Adverse mortality effect of central sympathetic inhibition with sustained-release moxonidine in patients with heart failure (MOXCON)

BACKGROUND

The association between sympathetic activation and mortality in chronic heart failure and the favorable effect of beta blocking drugs has raised the possibility of therapeutic efficacy for central sympathetic inhibition with sustained-release (SR) moxonidine, an imidazoline receptor agonist.

METHODS

A randomized double-blind, placebo-controlled trial was initiated in 425 centers in 17 countries with a plan to enter 4533 patients with New York Heart Association class II-IV heart failure and a reduced ejection fraction. Moxonidine SR or matching placebo was titrated to a target dose of 1.5 mg BID. The trial was powered to detect a 20% reduction in mortality, which required a total of 724 deaths.

FINDINGS

An early increase in death rate and adverse events in the moxonidine SR group led to premature termination of the trial because of safety concerns after 1934 patients were entered. Final analysis revealed 54 deaths (5.5%) in the moxonidine SR group and 32 deaths (3.4%) in the placebo group during the active treatment phase. Survival curves revealed a significantly (P=0.012) worse outcome in the moxonidine SR group. Hospitalization for heart failure, acute myocardial infarction and adverse events were also more frequent in the moxonidine SR group. Plasma norepinephrine was significantly decreased by moxonidine SR (-18.8% from baseline) vs. placebo (+6.9%).

INTERPRETATION

Early termination of the trial limited conclusions regarding the long-term effects of central sympathetic inhibition. Nonetheless, the excess early mortality and morbidity suggest the likelihood of an adverse effect of moxonidine SR and raise concerns regarding the efficacy of generalized sympathetic inhibition in heart failure.

[Current views on migraine and anti-migraine preparations]

On the basis of comprehensive experimental and clinical research the authors defined a variety of migraine-related mechanisms and schemes of migraine-correction by drugs, which should be both of the vascular- and general-actions to ensure an effective medication.

[Cardiovascular effects of cannabinoids]

The psychoactive properties of cannabinoids, the biologically active constituents of the marijuana plant, have long been recognized. Recent research has revealed that cannabinoids elicit not only neurobehavioral, and immunological, but also profound cardiovascular effects. Similar effects can be elicited by the endogenous ligand arachidonyl ethanolamine (anandamide) and 2-arachidonoyl-glycerol. The biological effects of cannabinoids are mediated by specific receptors. Two cannabinoid receptors have been identified so far: CB1-receptors are expressed by different cells of the brain and in peripheral tissues, while CB2-receptors were found almost exclusively in immune cells. Through the use of a selective CB1 receptor antagonist and CB1 receptor-knockout mice the hypotensive and bradycardic effects of cannabinoids in rodents could be attributed to activation of peripheral CB1 receptors. In hemodynamic studies using the radioactive microsphere technique in anesthetized rats, cannabinoids were found to be potent CB1-receptor dependent vasodilators in the coronary and cerebrovascular beds. Recent findings implicate the endogenous cannabinoid system in the pathomechanism of haemorrhagic, endotoxic and cardiogenic shock. Finally, there is evidence that the extreme mesenteric vasodilation, portal hypertension and systemic hypotension present in advanced liver cirrhosis are also mediated by the endocannabinoid system. These exciting, recent research developments indicate that the endogenous cannabinoid system plays an important role in cardiovascular regulation, and pharmacological manipulation of this system may offer novel therapeutic approaches in a variety of pathological conditions.

Preconditioning attenuates the shortening of recovery during coronary occlusion in isolated rabbit hearts with D-sotalol-induced long QT intervals

The effects of 20-min ligations of the anterior branch of the left coronary artery were studied in Langendorff-perfused rabbit hearts with 92 microM D-sotalol added to the perfusate to induce long QT intervals and triggered arrhythmias. Epicardial electrograms, a left ventricular endocardial monophasic action potential, and simulated X and Y lead electrocardiograms were used to characterize ventricular conduction and recovery. In contrast to previous work showing that global ischemia eliminated triggered activity, coronary occlusion did not alter its mean incidence. Although the anatomic distribution of earliest sites of epicardial activation by triggered beats was altered, triggered beats still appeared on the epicardial surface in the nonperfused regions. Coronary occlusion had a small and variable effect on epicardial conduction velocity but caused a significantly greater percent shortening of epicardial activation-recovery intervals in the nonperfused region of hearts given D-sotalol than in control hearts. In hearts given D-sotalol, preconditioning significantly attenuated the shortening of epicardial activation-recovery intervals in response to coronary occlusion. However, preconditioning had no effect on the mean incidence of triggered activity during coronary occlusion. Thus, the persistence of triggered activity and the shortened myocardial recovery time associated with coronary occlusion could contribute to increasing the likelihood of occurrence of malignant ventricular arrhythmias. Preconditioning by attenuating the shortening of recovery would be anti-arrhythmic.

Effects of sustained-release moxonidine, an imidazoline agonist, on plasma norepinephrine in patients with chronic heart failure

BACKGROUND

In chronic heart failure, sympathetic activation is increased. Moxonidine acts on central nervous system receptors to decrease sympathetic activation. We investigated the dose-response relationship of a new sustained-release (SR) preparation of moxonidine and the plasma concentration of norepinephrine in patients with chronic heart failure.

METHODS AND RESULTS

A total of 268 patients with chronic heart failure in NYHA functional class II to IV on optimal standard therapy were randomized to placebo or 1 of 5 doses of moxonidine SR: 0.3, 0.6, 0.9, 1.2, or 1.5 mg BID. After a dose-titration phase (7 weeks), patients were followed up for another 12 weeks at their maximally tolerated dose. Blood samples for plasma norepinephrine were collected at baseline and weekly during the initial 7 weeks, at week 19, and at the end of the study. At baseline and 7 and 19 weeks, sampling was also done 4 hours after the dose. After the active phases of the study, plasma norepinephrine was evaluated for an additional 3 days. A marked, statistically significant dose-related decrease in plasma norepinephrine was observed for predose levels as well as 4 hours after the dose at week 19. At the highest dose (1.5 mg BID), the trough reduction in norepinephrine was 52%. These reductions were accompanied by a modest decrease in heart rate, a modest increase in left ventricular ejection fraction, and a dose-related increase in adverse events.

CONCLUSIONS

Plasma norepinephrine was markedly reduced in a dose-related manner by moxonidine SR. This reduction was accompanied by evidence of reverse remodeling, but also by an increase in adverse events.

beta-Blockers and reduction of cardiac events in noncardiac surgery: scientific review

CONTEXT

Recent studies suggest that perioperatively administered beta-blockers may reduce the risk of adverse cardiac events in patients undergoing major noncardiac surgery.

OBJECTIVE

To review the efficacy of perioperative beta-blockade in reducing myocardial ischemia, myocardial infarction, and cardiac or all-cause mortality from randomized trials.

DATA SOURCES

A MEDLINE and conventional search of English-language articles published since 1980 was performed to gather information related to perioperative cardiac complications and beta-blockade. Reference lists from all relevant articles and published recommendations for perioperative cardiac risk management were reviewed to identify additional studies.

STUDY SELECTION AND DATA EXTRACTION

Prospective randomized studies (6) were included in the analysis if they discussed the impact of beta-blockade on perioperative cardiac ischemia, myocardial infarction, and mortality for patients undergoing major noncardiac surgery. Articles were examined for elements of trial design, treatment protocols, important biases, and major findings. These elements were then qualitatively compared.

DATA SYNTHESIS

We identified 5 randomized controlled trials: 4 assessed myocardial ischemia and 3 reported myocardial infarction, cardiac, or all-cause mortality. All studies sought to achieve beta-blockade before the induction of anesthesia by titrating doses to a target heart rate. Of studies reporting myocardial ischemia, numbers needed to treat were modest (2.5-6.7). Similarly modest numbers needed to treat were observed in studies reporting a significant impact on cardiac or all-cause mortality (3.2-8.3). The most marked effects were seen in patients at high risk; the sole study reporting a nonsignificant result enrolled patients with low baseline risk. As a group, studies of perioperative beta-blockade have enrolled relatively few carefully selected patients. In addition, differences in treatment protocols leave questions unanswered regarding optimal duration of therapy.

CONCLUSIONS

Despite heterogeneity of trials, a growing literature suggests a benefit of beta-blockade in preventing perioperative cardiac morbidity. Evidence from these trials can be used to formulate an effective clinical approach while definitive trials are awaited.

Antiglaucoma medication and clinical depression

OBJECTIVE

The aim of this paper is to alert the medical community to the potential risk of clinical depression following the use of antiglaucoma medication.

METHOD

The available literature concerning systemic side-effects of topical antiglaucoma medication and the association of these agents with clinical depression were reviewed. In addition, two cases are reported of the occurrence of clinical depression following use of topical betaxolol which only resolved completely after switching glaucoma medication.

RESULTS/CONCLUSIONS

The case reports presented here add to the increasing body of literature linking topical ophthalmic beta-adrenoceptor antagonists with depression. While these cases are uncommon, this phenomenon continues to be poorly recognized by the medical profession, psychiatrists, ophthalmologists and general practitioners alike.

Astroglial and microglial reaction after a partial nigrostriatal degeneration induced by the striatal injection of different doses of 6-hydroxydopamine

Astroglial and microglial activation was analyzed in adult male Wistar rats after a unilateral striatal injection of different doses (8, 4 and 1 micrograms) of 6-hydroxydopamine (6-OHDA). Control animals received the injection of the same volume of the solvent. The rotational behavior was registered by a rotometer 24 and 72 hours, 7, 10, 14 and 22 days after lesion. Following, animals were sacrificed and the tyrosine hydroxylase (TH) positive dopamine cells, the glial fibrillary acidic protein (GFAP) immunolabeled astrocytes and the OX42 immunoreactive microglia were visualized by mean of immunohistochemistry and quantified by stereologic method employing the optical disector and the point intercepts. The apomorphine (0.5 mg/kg)-induced circling behavior was seen only after 8 micrograms of 6-OHDA from 72 hours postlesion until sacrifice. Decreases of the TH immunoreactive terminals and cell bodies were found in the sampled fields of the striatum and pars compacta of the substantia nigra (SNc), respectively, after 8 and 4 micrograms of 6-OHDA. The GFAP immunohistochemistry revealed increases in the number/density of astroglial cells in the ipsilateral neostriatum (137% of control) and ipsilateral SNc (83% of control) and also in the volumeal fraction of the astroglial processes in the ipsilateral neostriatum (30% of control) and ipsilateral SNc (38% of control) in the rats with higher dose of the neurotoxin. Increases in the number of OX42 microglial labeled profiles and in the volumeal fraction of microglial processes were found in the ipsilateral neostriatum (67% and 27%, respectively, of control) and ipsilateral SNc (100% and 50%, respectively, of control) in the 8 micrograms 6-OHDA injected rats. These results suggest that the retrograde degeneration induced by a intrastriatal injection of a small dose of the 6-OHDA leads to an astroglial and microglial reaction in the nigrostriatal dopamine pathway. The interaction between activated glial cells may be involved in the wounding and repair events in the partial lesioned nigrostriatal system as well as in the paracrine responses to surviving dopamine neurons.

The medical management of adolescent heroin dependence

The use of heroin by American adolescents is at its highest levels since the heroin epidemic of the 1960s. This clinical perspective reviews medical issues associated with adolescent heroin dependence. Older, as well as potential newer, treatments for adolescent heroin dependence are discussed. Multiple obstacles face a heroin-dependent adolescent who seeks treatment, including a lack of evidenced-based research on pharmacotheraputic agents for this population, strict restrictions on medications with demonstrated efficacy in adults, and a general lack of clinical experience in treating this population.

Safety and tolerability of an aggressive tilt table test protocol in the evaluation of patients with suspected neurocardiogenic syncope

Safety and tolerability of a one-step tilt table test with high dose (5 micrograms/min) isoproterenol (ISO) without intermediate stages were evaluated in a symptomatic population of 300 patients referred for clinical syncope, near syncope, or dizziness. ISO has been used as a provocative test but remains controversial. A population of 118 male and 182 female patients with a mean age of 45 (range 5-90) years underwent 300 tests. Heart rate and blood pressure were monitored continuously. A positive test was one in which clinical symptoms were reproduced or hemodynamic criteria met. Patients were initially supine for 5 minutes followed by head upright tilt (HUT) to an angle of 80 degrees for 10 minutes. Negative tests were repeated with an infusion of ISO at a rate of 5 micrograms/min. HUT was positive in 133 (44.3%) of 300 tests. With a 10-minute HUT alone, only 17 (5.7%) of 300 of tests were positive. Of the initial negative tests, 273 of 283 were tested with ISO. With ISO, 116 (42.5%) of 273 were positive. ISO in high dose (5 micrograms/min) was used in 264 of 273 patients, while low dose (1.0-2.5 micrograms/min) was used in 9 of 273 under special circumstances. High dose ISO was tolerated in 164 (62.1%) of 264 patients, reduced in 87 (33%) of 264, and discontinued in 11 (4.2%) of 264. Reasons for reduction included tachycardia (40 patients), nausea (31 patients), chest pain (2 patients), arrhythmia (5 patients), or other (9 patients). Adverse effects resolved within 1 minute of dose reduction. This one-step high dose ISO protocol reproduced neurocardiogenic syncope in symptomatic patients who tested negative without ISO and was safe, tolerated, and expeditious.

Guanabenz combination therapy inhibits sympathetic nerve activity and regresses left ventricular hypertrophy

The cardiovascular and sympatholytic effects of combination therapy with guanabenz were examined in 26 patients (48 +/- 13 years old [mean +/- SD]) with stage 2 and 3 hypertension. Included in the study were patients under treatment with conventional antihypertensive drugs whose systolic and diastolic blood pressure was above 140 and 90 mmHg, respectively. Blood pressure, heart rate, and sympathetic parameters such as plasma concentration of norepinephrine and muscle sympathetic nerve activity at rest as well as during ambulatory conditions, 24-hour urinary excretion of norepinephrine, and low frequency (LF: 0.04-0.15 Hz)/high frequency (HF: 0.15-0.4 Hz) power ratio as a marker of cardiac sympathetic activity during 24 hours were examined before and after guanabenz (4-8 mg/d) combination therapy with first-line antihypertensive drugs such as diuretics. Left ventricular mass index (LVMI) was also calculated by conventional echocardiography. After 32 weeks of guanabenz combination therapy, systolic and diastolic blood pressure, heart rate, plasma and urinary excretion of norepinephrine, muscle sympathetic nerve activity, and LF/HF power ratio were significantly decreased, while neither LF nor HF power was changed. LVMI was also significantly decreased (270 +/- 81 vs. 236 +/- 83 g/m2, p < 0.005). These results indicate that guanabenz combination therapy inhibits sympathetic nerve activity under resting conditions as well as during ambulatory conditions and may accelerate regression of left ventricular hypertrophy in patients with moderate to severe hypertension.

Pharmacologic treatment of tic disorders

The approach to treating children and adolescents with tic disorders has evolved in recent years such that complete elimination of tics is no longer the primary goal of treatment. Indeed, given the high frequency of psychiatric comorbidity in TS, treatment planning begins with identification of target symptoms. Although traditional neuroleptics still represent standard treatment for tics, many families and clinicians are reluctant to use these agents because of concern about the potential for short- and long-term side effects. Thus, there is great interest in the newer atypical neuroleptics. Interest in the atypical neuroleptics is understandable, but much more study is needed before these agents can become first-line treatments for tics. A small group of non-neuroleptic medications have been used in the treatment of tics. Of these, clonidine, guanfacine, tetrabenazine, pergolide, and botulinum toxin injections have shown some promise for suppressing tics. To date, however, only clonidine has been evaluated in randomized, controlled trials, and the results are not consistent across studies. Although comorbid ADHD is common in children with TS, treatment with stimulant medications was not recommended in children with tics. Recent data suggest that stimulants may be used in some children with TS without adverse effects. Until more is known about which children with ADHD and tic disorders can be safely treated with stimulants, however, the use of stimulants in this population should be undertaken with caution. A handful of nonstimulant medications have been used in the treatment of ADHD with some success, but more study is needed for most of these agents. Evaluation of the stimulants and nonstimulants for the treatment of ADHD in children and adolescents with tic disorders is an area worthy of large controlled trials.

[Chronic renal failure--taming the sympathetic nervous system! New approach to delaying progression]

Previous research in end stage renal failure has focused on the renin-angiotensin-system. Today, we know, that in chronic renal failure sympathetic overactivity plays a pivotal role for progression of the disease and overall prognosis. The unique finding is that the damaged kidneys send afferent nerve impulses to the central nervous system to increase efferent sympathetic discharge. Systemically this sympathetic overactivity contributes to hypertension and associated cardiovascular complications. Locally in the kidney neurotransmitter release is enhanced, which induces proliferation thereby promoting loss of renal function. Consequently, it has been shown that pharmacological inhibition of sympathetic nerve activity prevents glomerulosclerosis and ameliorates proteinuria in models of chronic renal failure. Thus, the pathomechanism of sympathetic overactivity is likely to open a new therapeutic avenue for the treatment of hypertensive chronic renal failure patients.

[Alcohol withdrawal syndrome and delirium tremens. Diagnosis and therapy]

The alcohol withdrawal syndrome can be classified into three degrees of severity on the basis of the symptomatology, autonomic withdrawal, predelirium and delirium tremens. In American literature the severity of withdrawal is recorded using the CIWA-A scale (Clinical Institute Withdrawal Assessment--Alcohol). The pathophysiological causes lie in an imbalance between the inhibitory and excitatory neurotransmitters after giving up alcohol. This results in predomination by the excitatory system. Therapeutic intervention is possible here. Clomethiazole has effective sedative actions, stabilises the autonomic nervous system, and is an anticonvulsant. It is the drug of choice for autonomic withdrawal and predelirium. The benzodlazepines have a similar effect, but cannot be controlled so accurately. Carbamazepine can prevent withdrawal convulsions and progression of delirium. Clonidine acts on autonomic withdrawal and, together with neuroleptics and benzodiazepines, is easy to use parenterally for delirium tremens, while parenteral clomethiazole harbours dangers.

Guanfacine and secondary mania in children

INTRODUCTION

Guanfacine hydrochloride is an alpha-2 adrenergic agonist, which has gained recent attention in the field of child and adolescent psychiatry. This medication has been described as effective in the management of attention-deficit hyperactivity and tic disorders, with minimal side effects.

METHODS

Presented here are five cases of behavioral activation in children treated with guanfacine.

RESULTS

In each instance the clinical presentation resembled an acute hypomanic or manic episode. The dose of guanfacine was 0.5 mg/day. Later investigation revealed that all of the youngsters had clear risk factors (clinical and/or familial) for bipolar disorder.

CONCLUSIONS

It appears as though guanfacine may be capable of precipitating secondary mania in vulnerable children.

Parkinson's disease: a preliminary study of yohimbine challenge in patients with anxiety

In this pilot study, we performed an oral yohimbine challenge in 6 patients with Parkinson's disease (PD) and anxiety or depression, 2 parkinsonian patients without psychiatric illness, and 2 healthy control subjects to determine whether patients with Parkinson's disease and anxiety respond to this adrenergic agent in the same way patients with idiopathic anxiety disorders respond. Given the atypical nature of depression in Parkinson's disease (characterized by prominent anxiety), we also wanted to see if patients with Parkinson's disease and depression (but no history of anxiety) are susceptible to yohimbine-induced panic. Parkinsonian patients with anxiety developed panic attacks at frequencies comparable to primary psychiatric patients with panic disorder. The one patient with PD and a history of major depression alone developed a panic attack. Regardless of their history of anxiety or depression, parkinsonian patients demonstrated a vulnerability to yohimbine-induced somatic symptoms.

Treating men with predominantly nonpsychogenic erectile dysfunction with intracavernosal vasoactive intestinal polypeptide and phentolamine mesylate in a novel auto-injector system: a multicentre double-blind placebo-controlled study

OBJECTIVE

To study the effect of intracorporeal injection (IC) of vasoactive intestinal polypeptide (VIP) and phentolamine mesylate (PM) on men with erectile dysfunction (ED) of nonpsychogenic aetiology.

PATIENTS AND METHODS

The study comprised 236 men with primarily nonpsychogenic ED attending sexual dysfunction clinics at eight institutions. In an initial dose-assessment phase, the men were given IC injections of 25 micrograms VIP combined with PM 1.0 mg (VIP/P-1) or 2.0 mg (VIP/P-2) in a prefilled, single-use auto-injector. The main aetiologies of ED were arteriogenic (38), diabetes mellitus (DM) (39), neurogenic (35), mixed (90), and venous leakage (30). In a placebo-controlled phase, 171 patients were subsequently treated and self-administered up to 12 injections over a 6-month interval.

RESULTS

In the dose-assessment phase there was an overall response rate of 82%, with responses by aetiology as follows: arteriogenic (82%), DM (85%), neurogenic (86%), mixed (80%), and venous leakage (77%). In a subgroup of 159 patients who withdrew from previous IC therapies for ED, 64% responded with an erection suitable for intercourse. Of the 171 patients treated in the placebo-controlled phase, 75% responded to VIP/P-1 and 12% to placebo (P<0.001); 66% responded to VIP/P-2 and 18% to placebo (P<0. 001), with a median duration of erection of 56 min. The principal adverse event was transient facial flushing accompanying 40% of 1711 injections. There was no pain after injection and one episode of priapism (0.06%); only seven patients withdrew because of adverse events. Over 88% and 92% of patients were satisfied with the drug and auto-injector, respectively. More than 85% of patients and 77% of partners reported an improved quality of life.

CONCLUSION

The combination of VIP and PM at the dose used is a safe and effective means of treating male ED of primarily nonpsychogenic aetiology.

Clonidine overdose in childhood: implications of increased prescribing

OBJECTIVE

To highlight the increase in the number of cases of clonidine overdose admitted to a specialist paediatric hospital, with particular reference to the clinical features, clinical course and circumstances surrounding the incident.

METHODS

Cases of clonidine overdose were identified by review of the emergency department attendance register, the intensive care unit database and inpatient statistics collection. Case notes were reviewed to determine the clinical features, history and clinical course in each case.

RESULTS

Fifteen patients experienced 16 overdoses during the period 1990-97 inclusive. Only one case occurred before 1994. Depressed level of consciousness and bradycardia were the most common clinical manifestations, and were observed in 75 and 88% of cases respectively. There were no fatalities. Five patients received naloxone. Other treatment modalities included gastrointestinal decontamination, atropine, ventilation and inotropic support. Fourteen cases occurred in association with medication prescribed for attention-deficit hyperactivity disorder (ADHD).

CONCLUSION

Clonidine overdose is a potentially serious condition, often requiring intensive care management. Our experience suggests that it is a growing problem, related in part to its increased use in the treatment of ADHD. Preventive strategies, including raising the level of awareness of risks, changes to packaging and appropriate selection of patients for treatment, need consideration if further overdoses are to be prevented.

Chronic sympathetic suppression in the treatment of chronic congestive heart failure

Previous short-term studies demonstrated that treatment with clonidine produced significant hemodynamic improvement in patients with congestive heart failure (CHF). In this study we followed 12 CHF patients (10 M, 2 F age 63+/-11, 10 with ischemic cardiomyopathy and 2 with dilated cardiomyopathy) treated with 0.15 or 0.075 mg oral clonidine twice daily for 13+/-5 months (range 6-23). with functional evaluation at baseline, 6 weeks and 6 months. There was suppression of circulating catecholamines, associated with significant ameliorations in NYHA class, in duration of exercise tolerance (from 246+/-68 sec to 362+/-30 and 459+/-70 sec, respectively p < 0.02), in ejection fraction (from 32+/-7% to 35+/-5 and 39+/-7% p < 0.04) and in left ventricular enlargement as assessed echocardiographically. There were also improvements in a number of electrophysiologic parameters calculated by computerized analysis of ambulatory ECG tapes, such as heart rate variability, indicating diminished propensity to malignant arrhythmias, as confirmed by decreases in the numbers of isolated premature ventricular contractions, couplets and episodes of non-sustained ventricular tachycardia. The data suggest that chronic central sympathetic suppression with clonidine in CHF results in significant functional amelioration and improved electrophysiologic stability.

Clonidine and sleep apnea syndrome interaction: antagonism with yohimbine

A patient with sleep apnea syndrome, concurrently taking clonidine as an antihypertensive, presented with severe respiratory acidosis, hypotension, and associated central nervous system depression. Acidosis was improved by mechanical ventilation, and central nervous system (CNS) depression and hypotension were reversed with yohimbine. Clonidine may have an additive CNS depressive effect in sleep apnea syndrome and should be used with caution in such patients. Yohimbine's sympathetic-enhancing effects may be useful in clonidine toxic states.

Antagonist precipitated clonidine withdrawal in rat: effects on locus coeruleus neurons, sympathetic nerves and cardiovascular parameters

The goal of the present study was to examine the effect of clonidine withdrawal on the neural control of blood pressure. Rats were treated for 7-13 days with clonidine via osmotic minipumps (200 microg kg(-1) day(-1), s.c.). Controls received saline or were sham operated. Withdrawal was precipitated by the alpha2-adrenergic receptor (alpha2-AR) antagonist atipamezole. Most experiments were done under halothane anesthesia. Chronic treatment with clonidine did not change mean arterial pressure (MAP) or heart rate (HR) but raised femoral artery resistance and the activity of locus coeruleus neurons slightly. Atipamezole given to rats treated chronically with clonidine produced the following effects: no change in MAP, severe tachycardia, sustained increase in splanchnic sympathetic nerve discharge (SND; +75 +/- 13%), transient increase in lumbar SND (+23 +/- 7%), ON-OFF activity pattern in the locus coeruleus (LC). The ON phase of LC activity was synchronized with upswings of SND and with small changes in MAP. A second alpha2-AR antagonist, methoxyidazoxan, produced effects identical to those of atipamezole. Atipamezole given to control rats produced no effect on MAP, HR, SND or LC activity. Atipamezole reversed the hypotension, sympathoinhibition and bradycardia produced by acute administration of clonidine. In awake rats treated chronically with clonidine, atipamezole did not change MAP but produced arterial pressure lability and tachycardia. In conclusion, under anesthesia, selective alpha2-AR antagonists elicit a clonidine withdrawal syndrome that displays autonomic characteristics reminiscent of the spontaneous withdrawal syndrome found in awake rats. The most prominent features of this syndrome are tachycardia, sympathoactivation, lack of hypertension and an oscillating activity pattern of brainstem neurons leading to abrupt changes in SND and in MAP.

Outcomes of ultrarapid opiate detoxification combined with naltrexone maintenance and counseling

Combining naltrexone and clonidine under general anesthesia is being used to shorten opiate detoxification. This study determined the one-year relapse rate of persons detoxified using this ultrarapid method in conjunction with naltrexone maintenance and counseling. Structured telephone interviews were held with 83 out of a random sample of 113 male patients who were detoxified via the ultrarapid method more than one year before the interview (average 1.5 years) and their significant others. Relapse was defined as at least two weeks of daily opiate use. According to patients and significant others, 57 percent of patients had not relapsed. This rate is better than rates obtained in studies of other detoxification methods.

Vasoactive intestinal polypeptide and phentolamine mesylate administered by autoinjector in the treatment of patients with erectile dysfunction resistant to other intracavernosal agents

OBJECTIVE

To study the effect of vasoactive intestinal polypeptide (VIP) and phentolamine mesylate (PM) on patients in whom previous intracavernosal therapy had failed.

PATIENTS AND METHOD

The study comprised 70 consecutive patients attending a clinic for erectile dysfunction, in whom previous therapy with intracavernosal prostaglandin-E1 (20 microg and papaverine (30 mg) combined with 1 mg PM had failed. They were given intracavernosal injections, initially with 25 microg VIP/1 mg PM (VIP1) and if unsuccessful, 25 microg VIP/2 mg PM (VIP2). Both VIP1 and VIP2 were administered using a pre-filled ready-to-use autoinjector fitted with a 29 G needle. The patients were diagnosed as having spinal cord lesion (eight), diabetes (21), ischaemic heart disease (12), hypertension (six), other diagnoses (nine), or idiopathic causes (14).

RESULT

Forty-seven (67%) of patients achieved erections sufficient for sexual intercourse (33 on VIP1 and 14 on VIP2), initially under clinical supervision and subsequently during home use. Minor side-effects were transient facial flushing in 37 (53%), truncal flushing in six (9%), bruising in 14 (20%) and pain from the injection needle in eight (11%). No patients reported priapism or other serious adverse events.

CONCLUSION

The combination of VIP and PM at the dose used was a safe and effective treatment in patients in whom other therapies had failed.