Effect of cisapride and metoclopramide on digoxin bioavailability

Pharmacokinetics of digoxin were investigated in six healthy volunteers following one week of digoxin monotherapy 0.25 mg b.i.d., and during coadministration of metoclopramide 10 mg t.i.d. or cisapride 10 mg t.i.d.. Metoclopramide reduced the peak plasma concentration of digoxin from 1.5 +/- 0.2 ng/ml to 1.1 +/- 0.1 ng/ml (mean +/- SEM) (p = 0.05), cisapride lowered the peak concentration to 1.3 +/- 0.1 ng/ml (p = 0.14). Metoclopramide prolonged the time required to reach the peak concentration of digoxin from 2 hr to 2.7 hr (p = 0.17), cisapride did not. Digoxin AUC0-12 (743 +/- 79 ng/ml.min) was reduced by 12% on coadministration of cisapride (653 +/- 38 ng/ml.min, p = 0.22) and by 19% on coadministration of metoclopramide (605 +/- 34 ng/ml.min, p = 0.06). It is concluded that the gastrointestinal absorption of digoxin is reduced by both substances. Monitoring of the patient's clinical status should be recommended when metoclopramide and cisapride are coadministered.     

曲美布汀治疗功能性消化不良

目的 :比较曲美布汀与西沙必利、甲氧氯普胺治疗功能性消化不良的疗效及安全性。方法 :将2 80例功能性消化不良病人随机分为 3组 ,曲美布汀组 1 0 0例 [男性 3 9例 ,女性 61例 ,年龄 (4 1±s 1 4)a]给曲美布汀 2 0 0mg,po,tid;西沙必利组 90例 [男性 3 1例 ,女性 5 9例 ,年龄 (4 2± 1 3 )a]给西沙必利 1 0mg,po,tid ;甲氧氯普胺组 90例 [男性 3 0例 ,女性 60例 ,年龄 (4 3± 1 1 )a]给甲氧氯普氨1 0mg,po,tid。疗程均为2wk。结果 :总有效率曲美布汀组 85 % ,西沙必利组为 84% ,甲氧氯普胺组为 62 % ,经Ridit分析 ,曲美布汀、西沙必利 2组疗效差异无显著意义 (P >0 .0 5 ) ,曲美布汀、甲氧氯普胺 2组疗效差异有非常显著意义 (P <0 .0 1 )。不良反应曲美布汀、西沙必利 2组相近 ,曲美布汀组明显少于甲氧氯普胺组 (P <0 .0 5 )。结论 :曲美布汀治疗功能性消化不良近期疗效显著、安全 ,与西沙必利相近 ,优于甲氧氯普胺     

Use of metoclopramide, domperidone, and cisapride in the management of diabetic gastroparesis

The pathophysiology, diagnosis, and treatment of diabetic gastroparesis are reviewed, and the mechanisms of action, pharmacokinetics, clinical efficacy, adverse effects, and dosage of metoclopramide, domperidone, and cisapride are described. Diabetic gastroparesis is a state of delayed gastric emptying that reportedly affects 20-30% of diabetic patients. Symptoms include nausea, early satiety, postprandial bloating and fullness, and vomiting. Diabetic gastroparesis has been managed most successfully with drugs that stimulate gastric emptying. Of the three agents studied--metoclopramide, domperidone, and cisapride--only metoclopramide is commercially available in the United States. The clinical efficacy of metoclopramide, domperidone, and cisapride has been well documented in several placebo-controlled trials. Metoclopramide effectively decreases mean gastric emptying time, although tolerance to this stimulation of gastric emptying may develop with long-term therapy. However, symptomatic relief persists with long-term therapy because of metoclopramide's antiemetic properties. Domperidone, which has also been shown to stimulate gastric motility and to possess antiemetic properties, improves symptoms in patients suffering from diabetic gastroparesis. Cisapride appears to have continued beneficial effects on gastric motility with long-term therapy. All three agents have favorable adverse-effect profiles. Although metoclopramide is currently the first-line agent for the management of gastroparesis, domperidone and cisapride both possess properties that may make them useful alternatives in patients who are unresponsive to or cannot tolerate metoclopramide therapy.     

阿片样物质介导多潘立酮和西沙必利对小鼠的镇痛作用

To study the anti-nociceptive effect of domper-idone and cisapride in mice. METHODS: Initially, the effect of these drugs on motor activity was tested using rotarod. The anti-nociception was tested using chemical and mechanical assay. In the chemical assay, the number of abdominal constrictions either in the saline treated animals or in the domperidone/cisapride (1, 5, or 10 mg/kg either po or ip) treated mice, were recorded for a period of 30 min after acetic acid challenge (10 mLAg, of 0.6 % acetic acid ip). In the tail clip assay, the time taken by the mouse to make attempts to dislodge the bulldog clamp placed at the tail (reaction time) was recorded with a cut off time of 30 s. The role of opioid pathways was examined by pretreating the animals with naloxone (1 mg/kg, ip) 30 min prior to domperidone and cisapride. RESULTS: Domperidone and cisapride, both reduced the number of abdominal constrictions when given orally or intraperitoneally. Domperidone (5 mg/kg) inhibited it to the extent of 57.0 % a     

Ethnicity and the course of tardive dyskinesia in outpatients presenting to the motor disorders clinic at the Maryland psychiatric research center

BACKGROUND: Although newly emergent tardive dyskinesia (TD) is less of a concern, about one-fourth to one-third of patients on or previously on chronic first-generation antipsychotic agents have TD. The long-term course and outcome, as well as their predictors, are unknown. Earlier studies identify ethnicity as one of the risk factors for the development of TD, and case reports have noted a preponderance of African-American males in cohorts of patients with tardive dystonia. The current study examines the anatomic distribution and course of TD in a cohort of schizophrenia patients of European and African descent with TD who were referred to the Motor Disorders Clinic (MDC). METHODS: We evaluated data collected on 1149 TD patients who were given a focused neurologic examination for movement disorders. Movements were evaluated with the MPRC Scale for Involuntary Movements (IMS). All patients met RDC-TD criteria for diagnosis of persistent TD. One to 10-year follow-up data on 528 patients were evaluated to examine the course of TD following recommendations made to referring primary clinicians. Suggested interventions to referring primary clinicians included dose reduction of first-generation antipsychotic medication, or switching to a second-generation antipsychotic. RESULTS: Initial evaluation included 701 European American (EA) patients and 448 African-American (AA) patients. AA patients had a significantly higher proportion of males [chi(1) = 7.50, P < 0.05]. EA subjects had a higher mean age than AA patients 42.8 +/- 11.2 and 39.8 +/- 10.4, respectively [F(1,1147) = 22.27, P < 0.05]. Mean neuroleptic exposure (chlorpromazine equivalents) was similar in both groups after controlling for differences in age.Follow-up data analyzed in 528 patients (329 EA and 199AA) showed a significant ethnicity by TD interaction [F(1,504) = 4.26, P < 0.05]. Examination of body distribution of dyskinetic movements showed an effect of ethnicity. Subsequent analyses suggest EA patients experienced more improvement in TD over the course of follow up [F(1,319) = 22.39, P < 0.05] compared with AAs [F(1,189) = 1.58, P > 0.05]. These findings were unchanged when age, change in antipsychotic drug dose, and duration of follow-up were covaried. CONCLUSION: Reports from earlier studies note ethnicity (African descent) as a risk factor in the development of TD. Our study findings suggest ethnicity might be an important factor in predicting a poor course of TD.     

Comparison of the effect of cisapride and metoclopramide on morphine-induced delay in gastric emptying.

1. The effects of metoclopramide or cisapride on morphine-induced delay in gastric emptying in patients before surgery were compared. 2. Forty patients were allocated randomly to receive one of four premedications i.m.: placebo only, morphine 10 mg alone, morphine 10 mg with metoclopramide 10 mg and morphine 10 mg with cisapride 10 mg. Gastric emptying after each premedication was assessed indirectly from the rate of absorption of oral paracetamol. 3. Cisapride 10 mg reversed the delay in gastric emptying due to morphine. Its effects were significantly greater than those of metoclopramide 10 mg.     

Atypical antipsychotics and pituitary tumors: a pharmacovigilance study

STUDY OBJECTIVE: To analyze the disproportionality of reporting of hyperprolactinemia, galactorrhea, and pituitary tumors with seven widely used antipsychotic drugs. DESIGN: Retrospective pharmacovigilance study. DATA SOURCE: United States Food and Drug Administration's Adverse Event Reporting System (AERS) database. INTERVENTION: We initially identified higher-than-expected postmarketing reports of pituitary tumors associated with risperidone, a potent dopamine D2-receptor antagonist antipsychotic, by analyzing reporting patterns of these tumors in the AERS database. To further examine this association, we analyzed disproportionate reporting patterns of pituitary tumor reports for seven antipsychotics with different affinities for blocking D2 receptors: aripiprazole, clozapine, olanzapine, quetiapine, risperidone, ziprasidone, and haloperidol. MEASUREMENTS AND MAIN RESULTS: To conduct both of these analyses, we used the Multi-item Gamma Poisson Shrinker (MGPS) data mining algorithm applied to the AERS database. The MGPS uses a Bayesian model to calculate adjusted observed:expected ratios of drug-adverse event associations (Empiric Bayes Geometric Mean [EBGM] values) in huge drug safety databases. The higher the adjusted reporting ratio, or EBGM value, the greater the strength of the association between a drug and an adverse event. Risperidone had the highest adjusted reporting ratios for hyperprolactinemia (EBGM 34.9, 90% confidence interval [CI] 32.8-37.1]), galactorrhea (EBGM 19.9, 90% CI 18.6-21.4), and pituitary tumor (EBGM 18.7, 90% CI 14.9-23.3) among the seven antipsychotics, and one of the highest scores for all drugs in the AERS database. Some tumors were associated with visual field defects, hemorrhage, convulsions, surgery, and severe (>10-fold) prolactin elevations. The EBGM values for risperidone for these adverse events were higher in women, but high EBGM values for these events were also seen in men and children. Moreover, the rank order of the EBGM values for pituitary tumors corresponded to the affinities of these seven drugs for D2 receptors. CONCLUSION: Treatment with potent D2-receptor antagonists, such as risperidone, may be associated with pituitary tumors. These findings are consistent with animal (mice) studies and raise the need for clinical awareness and longitudinal studies.     

The effect of metoclopramide on QT dynamicity: double-blind,placebo-controlled,cross-over study in healthy male volunteers

BACKGROUND: Metoclopramide, a central and peripheral dopamine type 2 receptor antagonist, has been used as an attractive and safer alternative to cisapride. However, cardiac side-effects have also been reported with this drug. AIM: To evaluate the effects of intravenous metoclopramide administration on cardiac repolarization using QT dynamicity, a reliable indicator of arrhythmic side-effects. METHODS: The effect of metoclopramide on cardiac repolarization was evaluated in 10 healthy male volunteers in the supine position. Metoclopramide (10 mg) or placebo was administered intravenously at random in a double-blind, cross-over manner to the participants during continuous electrocardiographic recording in the supine position. The 30-min stationary segments of the recordings before and after drug administration were used to investigate QT dynamicity. RESULTS: Metoclopramide administration, but not placebo, resulted in steeper QT/RR slopes compared with the pre-drug values (metoclopramide: 0.037 +/- 0.004 vs. 0.064 +/- 0.012; P = 0.041; placebo: 0.045 +/- 0.006 vs. 0.050 +/- 0.004; P = 0.563). In a two-way analysis of variance model, metoclopramide administration also increased the QT variance independently (F = 6.225, P = 0.023). CONCLUSIONS: Metoclopramide administration increases the QT/RR slope and QT variance. These findings may partly explain the underlying mechanism of ventricular arrhythmias associated with metoclopramide.     

Trends in prescribing for vulvovaginal candidiasis in the United States

PURPOSE: To describe trends in visits to office-based physicians in the United States by females 15-64 years of age for vulvovaginal candidiasis and related antifungal prescribing. Since January 1991, intravaginal antifungal medications have been available over-the-counter in the United States to treat vulvovaginal candidiasis. METHODS: Data from the 1985 through 2001 National Ambulatory Medical Care Surveys (NAMCS) were examined. NAMCS is an annual national probability sample survey that collects data on the utilization of services provided by office-based physicians. RESULTS: The average annual visit rates for symptoms of vaginitis and a diagnosis of vulvovaginal candidiasis decreased by 55 and 72%, respectively. The intravaginal antifungal prescribing rate for vulvovaginal candidiasis declined by 41%. No trend was found for total antifungal prescribing; however, during the late 1990s, fluconazole was prescribed at approximately one-third of visits with a diagnosis of vulvovaginal candidiasis. CONCLUSION: These data suggest an increased trend in self-diagnosis and use of over-the-counter intravaginal antifungal medications. The shift from prescribing intravaginal antifungal preparations to fluconazole raises concern about the possible development of azole drug resistance. Educational efforts are needed to counter potential misuse of these medications that may contribute to increased infection with innately azole resistant non-albicans Candida species and chronic infection.     

The effects of S(-) and R(+) sulpiride, metoclopramide, cisapride and domperidone on the small intestine suggest DA2-receptors are involved in the control of small intestinal transit time in rats.

To study the effect of intraperitoneal S(-)sulpiride (1-15 mg/kg), R(+)sulpiride (5-10 mg/kg), metoclopramide (1-15 mg/kg), cisapride (10 mg/kg) and domperidone (5-10 mg/kg) on intestinal progression, rats were given the test drug followed by oral lactulose. Their hydrogen excretion was used to calculate the small bowel transit time (SBTT) and maximum peak time (MPT). Metoclopramide (7.5 mg/kg) had the greatest effect on SBTT (-25%), followed by S(-)sulpiride and domperidone. S(-)sulpiride (10 mg/kg) had the greatest activity on the MPT (-35.2%) followed by metoclopramide. R(+)sulpiride and cisapride did not modify SBTT and MPT. In conclusion S(-)sulpiride is the isomer active on intestinal transit and DA2-receptors seem important targets in the modulation of intestinal progression, since S(-)sulpiride, metoclopramide and domperidone are DA2-receptor antagonists, and R(+)sulpiride and cisapride are not. The H2 breath test proved a valid method for measuring the effect of drugs on the small intestine in animals.     

The gastroprokinetic and antiemetic drug metoclopramide is a substrate and inhibitor of cytochrome P450 2D6.

Metoclopramide is increasingly prescribed for conditions previously treated with cisapride, but its metabolic enzymology and drug interactions are poorly understood. Using human liver microsomes (HLMs) and recombinant human cytochromes P450 (P450), we identified the major route of metoclopramide oxidation and the P450 isoforms involved. We also documented the ability of metoclopramide to inhibit the P450 system, using isoform-specific substrate reaction probes of CYP1A2, 2C19, 2C9, 2D6, 2E1, and 3A4. Metoclopramide was predominantly N-dealkylated to monodeethylmetoclopramide, a metabolite that has not so far been described in humans. Formation rate of this metabolite followed Michaelis-Menten kinetics (K(m), 68 +/- 16 microM; V(max), 183 +/- 57 pmol/min/mg of protein; n = 3 HLMs). Of the isoform-specific inhibitors tested, 1 microM quinidine was a potent inhibitor of metoclopramide (25 microM) monodeethylation [by an average of 58.2%; range, approximately 38% (HL09-14-99) to 78.7% (HL161)] with K(i) values highly variable among the HLMs tested (K(i), mean +/- S.D., 2.7 +/- 2.8 microM; range, 0.15 microM in HL66, 2.4 microM in HL09-14-99, and 5.7 microM in HLD). Except troleandomycin, which inhibited metoclopramide metabolism in only one HLM (by approximately 23% in HL09-14-99), the effect of other inhibitors was minimal. Among the recombinant human P450 isoforms examined, monodeethylmetoclopramide was formed at the highest rate by CYP2D6 (V = 4.5 +/- 0.3 pmol/min/pmol of P450) and to a lesser extent by CYP1A2 (0.97 +/- 0.15 pmol/min/pmol of P450). The K(m) value derived (approximately 53 microM) was close to that from HLMs (68 microM). Metoclopramide is a potent inhibitor of CYP2D6 at therapeutically relevant concentrations (K(i) = 4.7 +/- 1.3 microM), with negligible effect on other isoforms tested. Further inhibition of CYP2D6 was observed when metoclopramide was preincubated with HLMs and NADPH-generating system before the substrate probe was added (maximum rate of inactivation, K(inact) = 0.02 min(-1), and the concentration required to achieve the half-maximal rate of inactivation, K'(i) = 0.96 microM), suggesting mechanism-based inhibition. Metoclopramide elimination is likely to be slowed in poor metabolizers of CYP2D6 or in patients taking inhibitors of this isoform, whereas metoclopramide itself could reduce the clearance of CYP2D6 substrate drugs.     

Detection of systemic hypersensitivity to drugs using standard guinea pig assays

The most commonly used assays designed to detect either skin or systemic immune-based hypersensitivity reactions are those using guinea pigs (GP). We obtained data from various FDA records to evaluate the correlation between GP assay results and reported post-marketing systemic hypersensitivity reactions. We examined the new drug application (NDA) reviews of approved drugs for the results of GP assays. Post-marketing human data were extracted from the FDA adverse event reporting system (AERS). Drug usage data were obtained from a commercial database maintained by IMS Health Inc. We found 83 (21%) of 396 drugs approved between 1978 and 1998 had reported GP test results. Among these 83 drugs, 14 (17%) were found to have positive results in at least one GP assay. Simple reporting index (RI) values for systemic hypersensitivity reactions were calculated from AERS data and usage to produce the index of adverse event reports per million shipping units of drug. A variety of definitions of positive human response were examined. A statistically significant association was seen for rash between post-marketing and clinical trials adverse event reports. No statistically significant associations between human data and GP test results were observed. These data suggest that standard GP assays have limited ability to predict human systemic hypersensitivity potential for pharmaceuticals.     

Suboptimal reporting of adverse medical events to the FDA Adverse Events Reporting System by nurse practitioners and physician assistants

Objectives: The Adverse Events Reporting System (AERS) of the FDA is used to identify toxicities of drugs that are on the market. Nurse practitioners (NP) and physician assistants (PA), having an increasing role in the delivery of medical care, are also needed to participate in post-marketing pharmacovigilance. This study was performed to assess awareness and use of the AERS in voluntary reporting of drug toxicities by NPs and PAs.

Methods: A cluster sample survey was issued at the Principles of Gastroenterology for the Nurse Practitioner and Physician Assistant course in August 2010. The survey assessed familiarity with the AERS, the number of adverse events seen and the frequency of reports sent to the AERS. NP and PA responses were compared using the two-tailed Fisher's exact.

Results: Of the 92 respondents, 67 (72%) were NPs and 24 (26%) PAs. Of the 50 (54%) respondents that reported being familiar with the AERS system, 20 (40%) incorrectly identified the methods to report using the AERS. Overall reporting of adverse events was low, particularly in respondents seeing 5–12 adverse events per year.

Conclusion: The study suggests that improved education regarding the importance of using AERS for pharmacovigilance is suggested for NPs and PAs. Due to the small size of the study, these data should be viewed as preliminary, pending a larger confirmatory study.     

Cisapride accelerates gastric emptying and mouth-to-caecum transit of a barium meal

Summary Cisapride (R 51 619) is a newly synthesized compound, which facilitates the release of acetylcholine in the myenteric plexus of the gut. Its effect on gastric emptying of a barium meal was evaluated in 84 patients under randomized, double-blind conditions. Two oral doses (5 mg and 10 mg) of cisapride were compared with a placebo, and two intravenous doses (4 mg and 8 mg) with a placebo and with 10 mg metoclopramide. All doses of cisapride and metoclopramide were significantly superior to placebo in accelerating gastric emptying, intensifying antral contractions and shortening the mouth-to-caecum transit time. The effects of 8 mg cisapride and 10 mg metoclopramide given intravenously were comparable.     

Prokinetic agents for the treatment of postoperative ileus in adults: a review of the literature

Metoclopramide, cisapride, and erythromycin are commonly administered to reduce the duration of postoperative ileus (POI). As these agents are not without potential adverse effects, their efficacy in shortening the duration of POI should be evaluated. The etiology of POI is not well understood and therefore the precise treatment is unclear. Nasogastric suction is the mainstay of therapy, and management of fluid and electrolyte imbalances is crucial. The role of prokinetic agents is less understood. Available literature evaluating these drugs specifically for POI were reviewed, but results are confounded by issues such as sample size, variability in types of operations performed, and insensitive end points (flatus, bowel sounds). No literature supports reducing the duration of POI with metoclopramide, and limited data show benefit with cisapride. Data evaluating erythromycin are sparse, and the drug is believed to be ineffective. Domperidone, a prokinetic agent not available in the United States, has not been evaluated in POI. Due to these limitations, treatment remains largely supportive with a limited role for prokinetic agents.     

A comparison of the pharmacokinetics of two dosing regimens of cisapride and their effects on corrected QT interval in premature infants

OBJECTIVE: To compare the pharmacokinetics of two dosing regimens of cisapride and their effects on QT(c) interval. DESIGN: Thirty-one pre-term infants were enrolled in two neonatal intensive care units. In 16 infants, cisapride was started at 0.2 mg/kg orally every 6 h (group A) and in 15 infants at 0.1 mg/kg orally every 3 h (group B). Electrocardiograms were performed before and after 72 h of treatment to calculate the QT(c) interval according to the Bazett formula. After 72 h of treatment, cisapride and norcisapride trough concentrations, and concentrations 1 h after the next cisapride administration were quantified in serum. A linear regression analysis was performed to analyse the effect of postnatal and postconception age. RESULTS: At the start of cisapride treatment, mean postnatal age was 22.9+/-13.9 days (mean+/-SD) for group A and 23.3+/-15.0 days for group B, and mean postconception age was 34.0+/-1.8 weeks for group A and 33.3+/-0.8 weeks for group B. The QT(c) interval increased equally in both groups (group A: +37+/-20 ms, and group B: + 38+/-25 ms; P=0.9). Mean concentration of cisapride 1 h after administration was, as expected from the dosing regimen, significantly higher in group A than in group B (123.7+/-43.2 ng/ml versus 86.7+/-27.8 ng/ml; P=0.03).The difference in trough concentration was not significant (107.4+/-44.3 ng/ml versus 78.2+/-35.4 ng/ml; P=0.09). There was a positive correlation between QT(c) prolongation and cisapride serum concentration (peak: R(2)=0.20, P=0.015; trough: R(2)=0.24, P=0.008) and an inverse correlation between postnatal age and concentration 1 h after administration concentration of cisapride (R(2)=0.19, P=0.02). No correlation was found for postconception age. CONCLUSION: Postnatal age has an inverse relationship with cisapride serum concentration in premature infants, whereas postconception age is not correlated. The maturation process of the biotransformation system of cisapride during the first weeks of life, triggered by birth, but independent of gestational age at birth can explain this observation. The effect of cisapride on cardiac repolarisation is positively related with the cisapride serum concentration. Administering cisapride every 3 h instead of every 6 h could be advantageous, as it is associated with lower peak cisapride serum concentrations. Further investigations are required to confirm this and its potential clinical benefit on QT(c )and arrhythmia risk.