From Fanny to Fernand: the development of consumerism in pain control during the birth process

Obstetric anesthesia has been the object of public interest and patient advocacy from its introduction in the 1840s to the present. Early arguments concerned the significance of pain in childbearing and became a popular issue involving physicians, clergymen, and journalists. The first obstetric anesthesia, either, given in the United States was administered in Cambridge, Massachusetts, in 1847. For the next several decades general anesthesia was the only feasible means of relieving labor pain. At the turn of the century a combination of scopolamine and morphine was introduced in the United States by a popular women's magazine; the National Twilight Sleep Association was launched. After the decline of this movement, the "natural" childbirth method came into national prominence. In spite of their differing pharmacologic characteristics, there are sociologic parallels between the patient advocacy of Twilight Sleep and that of psychoprophylaxis. This study focuses on the public perception of these movements, which were begun by physicians and subsequently endorsed by militant lay groups.

Antidepressant efficacy of the antimuscarinic drug scopolamine: a randomized, placebo-controlled clinical trial

CONTEXT

The need for improved therapeutic agents that more quickly and effectively treat depression is critical. In a pilot study we evaluated the role of the cholinergic system in cognitive symptoms of depression and unexpectedly observed rapid reductions in depression severity following the administration of the antimuscarinic drug scopolamine hydrobromide (4 microg/kg intravenously) compared with placebo (P = .002). Subsequently a clinical trial was designed to assess more specifically the antidepressant efficacy of scopolamine.

OBJECTIVE

To evaluate scopolamine as a potential antidepressant agent.

DESIGN

Two studies were conducted: a double-blind, placebo-controlled, dose-finding study followed by a double-blind, placebo-controlled, crossover clinical trial.

SETTING

The National Institute of Mental Health. Patients Currently depressed outpatients aged 18 to 50 years meeting DSM-IV criteria for recurrent major depressive disorder or bipolar disorder. Of 39 eligible patients, 19 were randomized and 18 completed the trial.

INTERVENTIONS

Multiple sessions including intravenous infusions of placebo or scopolamine hydrobromide (4 microg/kg). Individuals were randomized to a placebo/scopolamine or scopolamine/placebo sequence (series of 3 placebo sessions and series of 3 scopolamine sessions). Sessions occurred 3 to 5 days apart.

MAIN OUTCOME MEASURES

Psychiatric evaluations using the Montgomery-Asberg Depression Rating Scale and the Hamilton Anxiety Rating Scale were performed to assess antidepressant and antianxiety responses to scopolamine.

RESULTS

The placebo/scopolamine group showed no significant change during placebo infusion vs baseline; reductions in depression and anxiety rating scale scores (P<.001 for both) were observed after the administration of scopolamine compared with placebo. The scopolamine/placebo group also showed reductions in depression and anxiety rating scale scores (P<.001 for both) after the administration of scopolamine, relative to baseline, and these effects persisted as they received placebo. In both groups, improvement was significant at the first evaluation after scopolamine administration (P< or =.002).

CONCLUSION

Rapid, robust antidepressant responses to the antimuscarinic scopolamine occurred in currently depressed patients who predominantly had poor prognoses.

The usefulness of head-up tilt testing and hemodynamic investigations in the workup of syncope of unknown origin

To enhance the clinical evaluation of patients suffering from recurrent syncope of unknown origin, the integrity of mechanisms controlling blood pressure was examined in 151 patients utilizing a screening tilt test. Ninety-eight patients had an abnormal blood pressure and/or heart rate response to tilt testing, including provoked syncopal attacks in 63 patients. Whenever indicated, the screening tilt test was followed by blood volume and hemodynamic determinations, as well as autonomic nervous system testing to identify contributing pathophysiological abnormalities (hypovolemia, venous pooling, autonomic dysfunction). Detailed analysis of this battery of tests allowed us to conclude that: (1) The tilt test is commonly a provocative tool in the workup of patients with recurrent syncope due to vasovagal - vasodepressor reactions and other abnormalities of blood pressure regulation; (2) Its usefulness is augmented by associated hemodynamic and blood volume evaluations; (3) The identification of contributory pathophysiological mechanisms of blood pressure control facilitates specific therapeutic interventions.

Utility of upright tilt-table testing in the evaluation and management of syncope of unknown origin

PURPOSE

Vasovagally mediated hypotension and bradycardia are believed to be common, but difficult to diagnose, causes of syncope. Upright tilt-table testing has been proposed as a possible way to test for vasovagal episodes. This study investigated the clinical utility of this technique in the evaluation and management of patients with syncope of unknown origin.

PATIENTS AND METHODS

Twenty-five patients with recurrent unexplained syncope and six control subjects were evaluated by use of an upright tilt-table test for 30 minutes, with or without an infusion of isoproterenol (1 to 3 micrograms/minute given intravenously), in an attempt to provoke bradycardia, hypotension, or both. Of the 25 patients, there were 14 males and 11 females, with a mean age of 50 +/- 16 years. Six control patients with no history of syncope were also studied. All tilt-positive patients received therapy with either beta-blockers, disopyramide, transdermal scopolamine, or hydroflurocortisone, the efficacy of which was evaluated by another tilt-table test.

RESULTS

Syncope occurred in six patients (24%) during the baseline tilt and in nine patients (36%) during isoproterenol infusion (total positives, 60%). None of the controls had syncope during the test. All patients who had positive test results eventually became tilt-table-negative by therapy, and over a mean follow-up period of 16 +/- 2 months no further episodes have occurred.

CONCLUSION

From this study we conclude that upright tilt-table testing combined with isoproterenol infusion is clinically useful in the diagnosis of vasovagal syncope and the evaluation of pharmacologic therapy.

Replication of scopolamine's antidepressant efficacy in major depressive disorder: a randomized, placebo-controlled clinical trial

BACKGROUND

We previously reported that intravenous (IV) scopolamine administration produced rapid and robust antidepressant effects in a sample consisting of both unipolar and bipolar depressives. The present study aimed to replicate this finding in an independent sample limited to unipolar depressives.

METHODS

Outpatients with major depressive disorder (MDD; n = 23; 22 were included in analyses) participated in a double-blind, placebo-controlled, crossover trial. Subjects were randomized into either a P/S or S/P sequence (P = block of three placebo sessions; S = block of three scopolamine sessions; [4.0 microg/kg IV]). Sessions occurred 3 to 5 days apart, such that time spent in each block lasted 1.5 to 2 weeks and the interval between blocks was 3 to 5 days. The Montgomery-Asberg Depression Rating Scale (MADRS) served as the primary outcome measure.

RESULTS

Following the initial block, the group receiving scopolamine first (S/P) showed a 32% reduction in MADRS scores (p < .001), which exceeded the corresponding change of 6.5% under placebo (P/S; p = .009), confirming the a-priori hypothesis. Improvement was significant at the first evaluation that followed scopolamine administration (p = .011). In Block 2, the P/S group showed a 53% reduction in MADRS scores (p = .001) following scopolamine versus placebo, whereas the reduction seen in S/P subjects who received scopolamine during Block 1 persisted as they received placebo during Block 2. Scopolamine induced drowsiness, blurred vision, dry mouth, light-headedness, and reduced blood pressure, which were sufficiently well tolerated that no subject dropped out because of side effects.

CONCLUSIONS

These results replicate previous finding that scopolamine produces a rapid and robust antidepressant response.

Role of octreotide, scopolamine butylbromide, and hydration in symptom control of patients with inoperable bowel obstruction and nasogastric tubes: a prospective randomized trial

Bowel obstruction may be an inoperable complication in patients with end-stage cancer. Scopolamine butylbromide (SB) and octreotide (OCT) have been successfully used with the aim of reducing gastrointestinal (GI) secretions to avoid placement of a nasogastric tube (NGT); however, there have been no comparative studies concerning the efficacy of these drugs. Furthermore, there is little information about the role played by parenteral hydration in symptom control of these patients. In a prospective trial that involved all 17 inoperable bowel-obstructed patients presenting to our services with a decompressive NGT, patients were randomized to OCT 0.3 mg/day or SB 60 mg/day for 3 days through a continuous subcutaneous infusion. Clinical data, survival time, and the time interval from the first diagnosis of cancer to the onset of inoperable bowel obstruction were noted. The intensity of pain, nausea, dry mouth, thirst, dyspnea, feeling of abdominal distension, and drowsiness were assessed by means of a verbal scale before starting treatment with the drugs under study (T0) and then daily for 3 days (T1, T2, T3). Moreover, daily information was collected regarding the quantity of GI secretions through the NGT, the oral intake of fluids, the quantity of parenteral hydration, and the analgesic therapy used. The NGT could be removed in all 10 home care and in 3 hospitalized patients without changing the dosage of the drugs. OCT significantly reduced the amount of GI secretions at T2 (P = 0.016) and T3 (P = 0.020). Compared to the home care patients, the hospitalized patients received significantly more parenteral hydration (P = 0.0005) and drank more fluids (P = 0.025). There was no difference in the daily thirst and dry mouth intensity in relation to the amount of parenteral hydration or the treatment provided (OCT or SB). Independent of antisecretory treatment, the patients receiving less parenteral hydration presented significantly more nausea (T0 P = 0.002; T1 P = 0.001; T2 P = 0.003; T3 P = 0.001) and drowsiness at T3 (P < 0.5). Pain relief was obtained in all 17 patients and only two patients required an increase in morphine dose at T1. All patients with inoperable malignant bowel obstruction should undergo treatment with antisecretory drugs so as to evaluate the possibility of removing the NGT. When a more rapid reduction in GI secretions is desired, OCT should be considered as the first choice drug. Parenteral hydration over 500 ml/day may reduce nausea and drowsiness.

Effect of botulinum toxin in the treatment of drooling: a controlled clinical trial

OBJECTIVE

To investigate the clinical effectiveness of botulinum neurotoxin type A (BoNT) to reduce drooling in children with cerebral palsy (CP).

METHODS

A controlled clinical trial was performed in which the results of single-dose BoNT injections in the submandibular glands were compared with treatment with scopolamine. Forty-five children who had CP and experienced severe drooling were enrolled. Drooling severity was measured at baseline, during application of scopolamine, and at different intervals after BoNT injections up to 24 weeks, using the Drooling Quotient (DQ), the Teacher Drooling Scale (TDS), and Visual Analog Scales (VAS).

RESULTS

Drooling was reduced during scopolamine application as well as after BoNT injections. Compared with baseline, the mean DQ showed a significant decrease throughout the study. Greatest reductions were achieved 2 to 8 weeks after BoNT injection. No significant differences were found between scopolamine measurements and those up to 24 months after BoNT injection. Using VAS, parents recorded the effect on drooling in which significant differences were found between baseline VAS score and all follow-up assessments. According to our definition of "success to therapy," demanding a 2-point decrease on the TDS, 61.5% of patients responded to BoNT injections. Analysis of the DQ demonstrated a response rate of 53% of the patients to scopolamine and 48.7% to BoNT until 24 weeks after BoNT injections, the actual duration of this study. As a reaction to scopolamine, 71.1% of the patients had moderate to severe side effects. Only nonsevere, incidental side effects were reported after BoNT injections.

CONCLUSIONS

During scopolamine application as well as after intraglandular BoNT injections, a clinically relevant reduction in drooling was achieved in children with CP, demonstrating maximum effect 2 to 8 weeks after injections. This is the first controlled clinical trial that confirmed a significant effect of BoNT injections in the treatment of drooling. General anesthesia was needed for all children. BoNT injections show fewer and less serious side effects than transdermal scopolamine treatment.

Effect of cholinergic and anticholinergic agents on tardive dyskinesia

Tardive dyskinesia, like several other choreiform disorders, is felt to be primarily related to dopaminergic activity within the striatum. Physostigmine has been demonstrated to improve the abnormal movements in patients with tardive dyskinesia while scopolamine tends to aggravate abnormal movements and in some cases elicits abnormal movement not previously observed. This evidence supports the hypothesis that anticholinergic therapy in patients prone to develop tardive dyskinesia may increase the incidence of this disorder by lowering the threshold for the appearance of these movements.

Effects of scopolamine treatment on long-term behavioral deficits following concussive brain injury to the rat

Scopolamine (0.1, 1.0, or 10.0 mg/kg) or saline was systemically (i.p.) administered to rats 15 min prior to concussive fluid percussion brain injury. Animals pretreated with the 1.0 mg/kg dose exhibited significantly (P less than 0.05) less motor deficits and less body weight loss and recovered to baseline performance sooner than saline-treated rats. Mortality and associated convulsions were significantly lower in rats pretreated with the 1.0 mg/kg dose of scopolamine. A 1.0 mg/kg dose of scopolamine administered (i.p.) 30 s after injury also significantly reduced behavioral deficits. No differences were observed between saline- and scopolamine-treated animals in either the incidence or duration of transient apnea following injury. A 1.0 mg/kg dose of scopolamine administered (i.p.) 15 min prior to epidural clip compression of the spinal cord had no effect on the severity of motor function deficits assessed by an inclined plane test. The data from these experiments suggest muscarinic cholinergic involvement in at least some of the long-term behavioral deficits following mild and moderate levels of brain injury. These results suggest that muscarinic cholinergic antagonists may prove beneficial in the treatment of human head injury.

Comparison of octreotide and hyoscine butylbromide in controlling gastrointestinal symptoms due to malignant inoperable bowel obstruction

In advanced cancer patients with inoperable bowel obstruction, the administration of antisecretive and antiemetic drugs has proved to be effective in controlling gastrointestinal symptoms caused by bowel obstruction. However, controlled studies concerning the most effective antisecretive drug are lacking. The aim of this randomized controlled study was to determine whether octreotide or hyoscine butylbromide was the more effective antisecretive drug for use in states of inoperable bowel obstruction. Eighteen patients with inoperable bowel obstruction randomly received octreotide 0.3 mg daily (n = 9) or hyoscine butylbromide (HB) 60 mg daily (n = 9) s.c. The following parameters were measured: episodes of vomiting, nausea, drowsiness, continuous and colicky pain, using a Likert scale corresponding to a numerical value: (none 0, slight 1, moderate 2, severe 3) recorded before starting the treatment (T0) and 24 h (T1), 48 h (T2) and 72 h after (T3), and the mean daily amounts of fluids administered i.v. or s.c. during the period of study. Three patients dropped out of the study because data were incomplete. Octreotide treatment induced a significantly rapid reduction in the number of daily episodes of vomiting and intensity of nausea compared with HB treatment at the different time intervals examined. No relevant changes were found in dry mouth, drowsiness and colicky pain. Lower levels of hydration were associated with nausea regardless of the treatment. At the doses used in this study, octreotide was more effective than HB in controlling gastrointestinal symptoms of bowel obstruction. Further studies are necessary to understand the role of hydration more clearly in such a clinical situation.

Transdermal hyoscine (Scopolamine). A preliminary review of its pharmacodynamic properties and therapeutic efficacy

Hyoscine (scopolamine) is a competitive inhibitor of the muscarinic receptors of acetylcholine and it has been shown to be one of the most effective agents for preventing motion sickness. However, a relatively high incidence of side effects and a short duration of action has restricted the usefulness of this agent when administered orally or parenterally, and to counter this a novel transdermal preparation of hyoscine has been developed. Pharmacokinetic studies indicate that this new method for administering hyoscine controls the absorption process and the rate of drug entry into the systemic circulation over an extended period (72 hours), providing a means of delivery which is similar to a slow intravenous infusion. However, recent evidence suggests that the response to transdermal hyoscine treatment is variable and this may reflect pharmacokinetic differences between individuals. Controlled therapeutic trials have indicated that a single transdermal hyoscine patch is significantly superior to placebo and oral meclozine (meclizine) in preventing motion sickness. Trials comparing transdermal hyoscine with oral dimenhydrinate have failed to establish any significant differences in efficacy between the 2 drugs in small numbers of subjects, although there was always a more favourable trend towards the transdermal system. In patients with acute vertigo, transdermal hyoscine and oral meclozine were equally efficacious and both were significantly better than placebo in reducing the number of attacks of vertigo. Although transdermal hyoscine has been associated with a lower incidence of side effects than orally or parenterally administered hyoscine hydrobromide, adverse systemic effects have still been frequently reported. Most commonly cited have been dry mouth, drowsiness and impairment of ocular accommodation, including blurred vision and mydriasis (some ocular effects reported may be due to finger-to-eye contamination). Adverse central nervous system (CNS) effects, difficulty in urinating, rashes and erythema have been reported only occasionally. Thus, preliminary evidence suggests transdermal hyoscine may offer an effective and conveniently administered alternative for the prevention of motion-induced nausea and vomiting in certain situations. However, the duration of its clinical effectiveness, and its relative efficacy and tolerability compared with other agents needs to be confirmed in a few additional well-designed studies.

Recurrent erosion of the cornea

Altogether, 80 patients aged between 24 and 73 years with recurrent erosion of the cornea have been studied and compared with a control group of 200. The patients' erosions were divisible into macroform and microform types. The macroform occurred in 10%, the microform in 56%, and both types in the same patients in 31%. The macroform was more commonly related to trauma than the microform. However, many (40%) were spontaneous in origin. The most common cause of the initial trauma was a finger nail. The recurrences occurred at around the time of waking, either just before or just after. Difficulty in opening the eye occurred in 10%. There was little evidence of precipitating factors, but eye rubbing was admitted by 10% and barbiturates were implicated in 3%. The corneae were examined in the healed state, when a high incidence (59%) were found to have superficial corneal dystrophies of the fingerprint lines, bleb, and Bietti's lacunar (map-like) types. These are considered individually, particular attention being paid to the distinction between the various types of line resembling the fingerprint line. Epithelial microcysts were also a common finding (59%) and were sometimes of the Cogan type. In only 11% of patients were there no corneal signs in the healed state. The need for careful examination of the cornea by retroillumination, using both the iris and the fundus, is stressed. The control group, in contrast, showed a very low incidence of dystrophies and cysts. Treatment was given initially with either drops or ointment and no differences in healing were found. Debridement was performed in 12 eyes as an initial treatment and also in four eyes which were not healing on medical treatment. Debridement assisted healing, but did not prevent recurrence. One eye was treated with debridement and scarification and seven with carbolization. These procedures appeared to reduce the recurrence rate. Sodium chloride ointment 5% was found useful as a prophylactic taken at bedtime, and the recurrence rate increased when it was withdrawn.

Transdermal scopolamine reduces nausea and vomiting after outpatient laparoscopy

The authors evaluated the effect of transdermal scopolamine on the incidence of postoperative nausea, retching, and vomiting after outpatient laparoscopy in a double-blind, placebo-controlled study. A Band-Aid-like patch containing either scopolamine or placebo was placed behind the ear the night before surgery. Anesthesia was induced with fentanyl (0.5-2 micrograms/kg iv), thiopental (3-5 mg/kg iv), and succinylcholine (1-1.5 mg/kg iv) and maintained with isoflurane (0.2-2%) and nitrous oxide (60%) in oxygen. Scopolamine-treated patients had less nausea, retching, and vomiting compared with placebo-treated patients (P = 0.0029). Severe nausea and/or vomiting was present in 62% of the placebo group but only 37% of those getting the scopolamine patch. Repeated episodes of retching and vomiting were also less frequent in the scopolamine group compared with the placebo group (23% vs. 41%; P = 0.0213) as was the need for additional antiemetic therapy (13% vs. 32%; P = 0.0013). Patients in the scopolamine group were also discharged from the hospital sooner (4 +/- 1.3 vs. 4.5 +/- 1.5 h; P = 0.0487). Side effects were more frequent among those patients treated with the scopolamine patch (91% vs. 45%; P less than 0.05) but were not troublesome. The authors conclude that transdermal scopolamine is a safe and effective antiemetic for outpatients undergoing laparoscopy.

Retardation of amygdala kindling by antagonism of NMD-aspartate and muscarinic cholinergic receptors: evidence for the summation of excitatory mechanisms in kindling

DL-2-amino-5-phosphonovaleric acid (APV), a specific antagonist of N-methyl-D-aspartate (NMDA) receptors, was administered alone and in combination with scopolamine (SCO), an antagonist of muscarinic cholinergic receptors, to different groups of rats undergoing electrical kindling of the amygdala. Both groups were significantly retarded in their rate of kindling during 15 drug sessions compared to controls, and the group receiving APV and SCO kindled significantly slower than the group receiving APV alone. These results indicate that both NMDA and muscarinic cholinergic receptors are involved in kindling of the amygdala, and implicate a mechanism involving the summation of excitatory neurotransmission in kindling of the amygdala.

The efficacy and safety of transdermal scopolamine for the prevention of postoperative nausea and vomiting: a quantitative systematic review

The role of scopolamine administered via transdermal therapeutic systems in the prevention of postoperative vomiting, nausea, and nausea and vomiting is unclear. We performed a systematic search for full reports of randomized comparisons of transdermal scopolamine with inactive control. Dichotomous data were extracted. In the meta-analysis, relative risks and numbers-needed-to-treat/harm were calculated with 95% confidence intervals (CI). In 23 trials, 979 patients received transdermal scopolamine, and 984 patients received placebo. Sensitivity analyses were performed using restricted data for truncated control event rates (40%-80%) and for large trials. With these data, the relative risks for postoperative vomiting (five reports), nausea (five reports), nausea and vomiting (eight reports), and rescue treatment (three reports) were 0.69 (95% CI, 0.58-0.82), 0.69 (95% CI, 0.54-0.87), 0.76 (95% CI, 0.66-0.88), and 0.68 (95% CI, 0.54-0.85), respectively. This means that of 100 patients who receive transdermal scopolamine, approximately 17 will not experience postoperative vomiting who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, eight will report dry mouth, two will report dizziness, one will be classified as being agitated, and 1-13 patients who are prescribed transdermal scopolamine will not use it correctly. The timing of application does not alter efficacy.

IMPLICATIONS

Of 100 patients who receive transdermal scopolamine, approximately 17 will not vomit in the postoperative period who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, and eight will report dry mouth. Incorrect use further limits its efficacy.

A study comparing hyoscine hydrobromide and glycopyrrolate in the treatment of death rattle

This study looked at the efficacy of drug treatment in managing death rattle in a 30-bedded specialist palliative care unit. The study was conducted in two phases. In the first, patients received hyoscine hydrobromide as the antimuscarinic; glycopyrrolate was used in the second phase. The patients in the two phases were well matched for diagnosis, age, sex and duration of death rattle. A noise score scale of 0-3 was used, which was separately validated using a verbal rating scale and noise-meter readings. Noise scores were taken at the start; 30 min after an antimuscarinic drug was administered; an hour after the initial injection if a repeat dose was given at 30 min; and 4-hourly thereafter. Drug charts of all patients with death rattle were analysed to ascertain the amount of each drug given and the cost. The incidence of death rattle was 44% in phase I, and 36% in phase II. The percentage of patients with reduced noise scores 30 min after one injection of hyoscine was significantly greater than after one dose of glycopyrrolate (56% vs 27%, P = 0.002). The need for a second injection after 30 min was less using hyoscine (33% vs 50%, P = 0.03). There was no statistically significant difference in improvement at 1 h, or at the last recorded score before death. A comparison of the cost of drug treatment using hyoscine or glycopyrrolate was made, and the potential reduction in cost per patient in the glycopyrrolate group was largely offset by increased expenditure on other drugs, especially diamorphine, midazolam and levomepromazine. The results of this study suggest that: (1) glycopyrrolate 0.2 mg is less effective at reducing death rattle than hyoscine hydrobromide 0.4 mg when assessed at 30 min, (2) the use of glycopyrrolate may lead to an increased need for other sedative or anti-emetic medication such as diamorphine, midazolam or levomepromazine, and (3) the cost benefit of using glycopyrrolate over hyoscine hydrobromide is a small part of the total drug budget, and may be less than anticipated due to the increased need of these other drugs.

Effects of ginger on motion sickness susceptibility and gastric function

This study was designed to evaluate the antimotion sickness activity of ginger root (Zingiber officinale) and to characterize the effects of ginger on gastric function. Twenty-eight human volunteers participated in the project. Subjects made timed head movements in a rotating chair until they reached an endpoint of motion sickness short of vomiting (malaise III or M-III). Each subject was tested with either ginger or scopolamine and a placebo. A substance was judged to possess antimotion sickness activity if it allowed a greater number of head movements compared to placebo control. Gastric emptying of a liquid was measured by nuclear medicine techniques in normal and motion sick subjects. Gastric electrical activity was monitored by cutaneous (surface) electrodes positioned over the abdominal area. Powder ginger (whole root, 500 or 1,000 mg) or fresh ginger root (1,000 mg) provided no protection against motion sickness. In contrast, subjects performed an average of 147.5 more head movements (p less than 0.01) after scopolamine (0.6 mg p.o.) than after placebo. The rate of gastric emptying was significantly (p less than 0.05) slowed when tested immediately after M-III but was inhibited less when tested 15 min after M-III. Powdered ginger (500 mg) had no effect on gastric emptying in normal or motion-sick subjects. Gastric motility was also changed during motion sickness. The frequency of the electrogastrogram (EGG) was increased after M-III (tachygastria) and the normal increase in EGG amplitude after liquid ingestion was reduced in motion sick subjects. Although powdered ginger (500 mg) partially inhibited tachygastria in motion sickness, it did not enhance the EGG amplitude in motion sick subjects. We conclude that ginger does not possess antimotion sickness activity, nor does it significantly alter gastric function during motion sickness.

Receptor mechanisms and circuitry underlying NMDA antagonist neurotoxicity

NMDA glutamate receptor antagonists are used in clinical anesthesia, and are being developed as therapeutic agents for preventing neurodegeneration in stroke, epilepsy, and brain trauma. However, the ability of these agents to produce neurotoxicity in adult rats and psychosis in adult humans compromises their clinical usefulness. In addition, an NMDA receptor hypofunction (NRHypo) state might play a role in neurodegenerative and psychotic disorders, like Alzheimer's disease and schizophrenia. Thus, understanding the mechanism underlying NRHypo-induced neurotoxicity and psychosis could have significant clinically relevant benefits. NRHypo neurotoxicity can be prevented by several classes of agents (e.g. antimuscarinics, non-NMDA glutamate antagonists, and alpha(2) adrenergic agonists) suggesting that the mechanism of neurotoxicity is complex. In the present study a series of experiments was undertaken to more definitively define the receptors and complex neural circuitry underlying NRHypo neurotoxicity. Injection of either the muscarinic antagonist scopolamine or the non-NMDA antagonist NBQX directly into the cortex prevented NRHypo neurotoxicity. Clonidine, an alpha(2) adrenergic agonist, protected against the neurotoxicity when injected into the basal forebrain. The combined injection of muscarinic and non-NMDA Glu agonists reproduced the neurotoxic reaction. Based on these and other results, we conclude that the mechanism is indirect, and involves a complex network disturbance, whereby blockade of NMDA receptors on inhibitory neurons in multiple subcortical brain regions, disinhibits glutamatergic and cholinergic projections to the cerebral cortex. Simultaneous excitotoxic stimulation of muscarinic (m(3)) and glutamate (AMPA/kainate) receptors on cerebrocortical neurons appears to be the proximal mechanism by which the neurotoxic and psychotomimetic effects of NRHypo are mediated.

Transdermal scopolamine in the prevention of motion sickness at sea

Studies were conducted to evaluate the efficacy of scopolamine, absorbed through intact skin, in preventing motion sickness at sea. Efficacy of transdermal scopolamine was compared with oral dimenhydrinate and placebo. Transdermal applications were made 4 to 16 hr before exposure to motion. Dimenhydrinate or placebo was given 1.5 hr before motion and again 2.5 hr after motion began. Comparison with placebo indicated that transdermal scopolamine provided protection against motion sickness at a significance level of p = 0.0001 and oral dimenhydrinate at a level of p = 0.05. Dry mouth, drowsiness, and blurred vision associated with transdermal scopolamine therapy were minimal.

Potential of pretreatment neural activity in the visual cortex during emotional processing to predict treatment response to scopolamine in major depressive disorder

CONTEXT

The need for improved treatment options for patients with major depressive disorder (MDD) is critical. Faster-acting antidepressants and biomarkers that predict clinical response will facilitate treatment. Scopolamine produces rapid antidepressant effects and thus offers the opportunity to characterize potential biomarkers of treatment response within short periods.

OBJECTIVE

To determine if baseline brain activity when processing emotional information can predict treatment response to scopolamine in MDD.

DESIGN

A double-blind, placebo-controlled, crossover study together with repeated functional magnetic resonance imaging, acquired as participants performed face-identity and face-emotion working memory tasks.

SETTING

National Institute of Mental Health Division of Intramural Research Programs.

PARTICIPANTS

Fifteen currently depressed outpatients meeting DSM-IV criteria for recurrent MDD and 21 healthy participants, between 18 and 55 years of age.

MAIN OUTCOME MEASURE

The magnitude of treatment response to scopolamine (percentage of change in the Montgomery-Asberg Depression Rating Scale score between study end and baseline) was correlated with blood oxygen level-dependent (BOLD) signal associated with each working memory component (encode, maintenance, and test) for both identity and emotion tasks. Treatment response also was correlated with change in BOLD response (scopolamine vs baseline). Baseline activity was compared between healthy and MDD groups.

RESULTS

Baseline BOLD response in the bilateral middle occipital cortex, selectively during the stimulus-processing components of the emotion working memory task (no correlation during the identity task), correlated with treatment response magnitude. Change in BOLD response following scopolamine administration in overlapping areas in the middle occipital cortex while performing the same task conditions also correlated with clinical response. Healthy controls showed higher activity in the same visual regions than patients with MDD during baseline.

CONCLUSION

These results implicate cholinergic and visual processing dysfunction in the pathophysiology of MDD and suggest that neural response in the visual cortex, selectively to emotional stimuli, may provide a useful biomarker for identifying patients who will respond favorably to scopolamine.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00055575.