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At least 19 recordsLinked to original sources
PubMed2000

Meclizine for prevention of nausea associated with use of emergency contraceptive pills: a randomized trial.

OBJECTIVE: We conducted a randomized trial to determine whether pretreatment with meclizine reduces the incidence of nausea and vomiting associated with the Yuzpe regimen of emergency contraception. METHODS: We randomly assigned 343 women aged 18-45 years who were not at risk for pregnancy to pretreatment with 50 mg of meclizine, placebo, or no drug 1 hour before the first of two doses of emergency contraceptive pills. We asked participants to complete three questionnaires over the following 48 hours. RESULTS: The incidence of nausea was 47% in the group pretreated with meclizine and 64% in the other two groups (relative risk adjusted for center 0.7, 95% confidence intervals 0.6, 0.9 for comparisons of meclizine with both placebo and no drug). The severity of nausea and the incidence of vomiting were also significantly lower in the meclizine pretreatment group than in the other two groups. Drowsiness was reported by about twice as many women in the meclizine pretreatment group (31%) than in the other two groups (13% in the placebo group, 16% in the no-pretreatment group; P < .01 for both comparisons). CONCLUSION: Meclizine is effective for preventing nausea and vomiting associated with the Yuzpe regimen of emergency contraceptive pills. Women using this drug should be cautioned to anticipate drowsiness.

Adolescent↗
PubMed2004

Meclizine is an agonist ligand for mouse constitutive androstane receptor (CAR) and an inverse agonist for human CAR.

The constitutive androstane receptor (CAR, NR1I3) is a key regulator of xenobiotic and endobiotic metabolism. The ligand-binding domains of murine (m) and human (h) CAR are divergent relative to other nuclear hormone receptors, resulting in species-specific differences in xenobiotic responses. Here we identify the widely used antiemetic meclizine (Antivert; Bonine) as both an agonist ligand for mCAR and an inverse agonist for hCAR. Meclizine increases mCAR transactivation in a dose-dependent manner. Like the mCAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene, meclizine stimulates binding of steroid receptor coactivator 1 to the murine receptor in vitro. Meclizine administration to mice increases expression of CAR target genes in a CAR-dependent manner. In contrast, meclizine suppresses hCAR transactivation and inhibits the phenobarbital-induced expression of the CAR target genes, cytochrome p450 monooxygenase (CYP)2B10, CYP3A11, and CYP1A2, in primary hepatocytes derived from mice expressing hCAR, but not mCAR. The inhibitory effect of meclizine also suppresses acetaminophen-induced liver toxicity in humanized CAR mice. These results demonstrate that a single compound can induce opposite xenobiotic responses via orthologous receptors in rodents and humans.

Animals↗
PubMed1986

Alleviation of induced vertigo. Therapy with transdermal scopolamine and oral meclizine.

Twelve healthy subjects received seven-day treatments on a randomized, double-blind, crossover basis, of a transdermal scopolamine system, oral meclizine, and placebo, separated by one-week intervals. Just prior to each treatment, and on days 1 and 7 of each treatment, subjects received two warm (44 degrees C) caloric irrigations of each external auditory canal. Following each irrigation, subjects rated their vertigo symptoms. Subjects reported on their side effects daily throughout each treatment period. Vertigo symptoms on day 1 of treatment were significantly less with transdermal scopolamine than oral meclizine or placebo and on day 7 were significantly less with both scopolamine and meclizine than the placebo. On day 1, meclizine did not reduce vertigo symptoms significantly when compared with the placebo. Drowsiness was greater with use of oral meclizine than transdermal scopolamine.

Dehydration↗
PubMed1992

Central nervous system effects of meclizine and dimenhydrinate: evidence of acute tolerance to antihistamines.

Relative daytime drowsiness and performance impairment produced by meclizine and dimenhydrinate was assessed in 24 healthy male volunteers. Subjects received either dimenhydrinate, 100 mg, at 8:00 AM, 12:00 PM, and 4:00 PM; meclizine, 50 mg, at 8:00 AM, with placebo at 12:00 PM and 4:00 PM; or placebo at all three times in this randomized, double-blind, three-way crossover study. Impairment of mental performance was assessed by choice reaction time testing and digit symbol substitution scores. Drowsiness was self-assessed on the Stanford Sleepiness Scale and on a visual analog scale. Both antihistamines produced changes in digit symbol substitution, recognition time, and subjective assessments of sleepiness different from placebo. Expressed as change from baseline, the greatest reductions in digit symbol substitution scores after dimenhydrinate occurred 3 hours after the first dose (6.6 +/- 7) and were not different from the greatest measured change after meclizine (5.8 +/- 8), which occurred 9 hours after the dose was administered. Similar results were obtained with the other psychometric test scores. Self-rated sleepiness after dimenhydrinate was greatest 1 hour after the first dose, and was significantly greater than the largest degree of sleepiness after meclizine, which occurred at 7 hours after the dose. The effects of the first dose of dimenhydrinate on psychometric test scores were compared with the magnitude of the effects produced by subsequent doses. The magnitude of effect of the first dose of dimenhydrinate was significantly greater than the magnitude of effect produced by subsequent doses. The data suggest the possibility that acute tolerance to central nervous system impairment develops with multiple doses of dimenhydrinate.

Adolescent↗
PubMed1978

Selected ion monitoring assay for meclizine in human plasma.

A method has been developed for the quantification of meclizine in human plasma using gas chromatography mass spectrometry. Pentadeuterated meclizine was synthesized and used as an internal standard. The method gave linear results over a concentration range of 5-200 ng ml-1 and was used to determine plasma levels of meclizine following administration to a male volunteer.

Chromatography, Gas↗
PubMed1985

Comparison of meclizine levels in the plasma of rats and dogs after intranasal, intravenous, and oral administration.

Meclizine, used prophylactically for the prevention of motion sickness and vertigo, is presently available only in oral form. We report herein that, when given intranasally, meclizine dihydrochloride is absorbed in rats about half as effectively as when given intravenously, but about six times more effectively than after oral administration, as estimated by the area under the plasma concentration-time curve. The mean times to peak levels in plasma are about 8.5 min after an intranasal dose and 49.0 min after oral delivery. We extended these studies to a second species, the beagle dog, and achieved qualitatively similar results with a new formulation (Mecnazone; Nastech Pharmaceutical Co., Inc.). The fraction absorbed intranasally was about 0.89 that of an equivalent intravenous dose but about four times that of an equivalent oral administration. In these studies, the mean times to peak levels in plasma was 11.9 min after an intranasal dose and 70.0 min after an oral dose. Terminal elimination kinetics were the same for all routes within each species. Intranasal delivery of meclizine therefore appears to be superior to the oral route for the more rapid achievement of substantial levels in plasma at a reduced dose.

Administration, Intranasal↗
PubMed1977

Determination of meclizine hydrochloride by ion-pair extraction with methyl orange.

A method, based on ion-pair extraction, is described for the quantification of meclizine hydrochloride in various pharmaceutical dosage forms, for content uniformity determination, and for concentration monitoring in dissolution and bioavailability studies. Methyl orange, dissolved in pH 2.8 MacIlvaine buffer, gave excellent recovery of meclizine after its isolation from aqueous solutions of gelatin, urine, and blood serum. The chloroform-extracted molecular species appeared to be a 1:1 ion-pair. Beer's law was obeyed for a wide concentration range. Because the extracted species seemed well defined and stable and since a surface or an interphase adsorption phenomenon was not a problem, the reported method is considered sensitive, accurate, precise, rapid, and simple.

Azo Compounds↗
PubMed2003

Quantitative enantiomeric analysis of chlorcyclizine, hydroxyzine, and meclizine by capillary electrophoresis.

A simple capillary zone electrophoresis method was developed for the quantitative enantiomeric analysis of piperazine antihistamines with teratogenic suspicion in animals. Enantioseparation of chlorcyclizine, hydroxyzine, and meclizine was performed in glycine buffer (0.6 mol L(-1); pH 3.00) with sulfated beta-cyclodextrin (5 mg mL(-1)) as a chiral selector; and the separated drugs were monitored by ultra-violet detector. The lower quantitation of the individual enantiomer is attainable at 10 micro mol L(-1), using an achiral piperazine drug (cyclizine) as internal standard. The method is simple and rapid with a short run time (<5 min) for the analysis of chlorcyclizine, hydroxyzine or meclizine enantiomers.

Animals↗
PubMed1984

Transdermal scopolamine, oral meclizine, and placebo in motion sickness.

The efficacy of transdermal scopolamine, oral meclizine, and placebo in protection against motion sickness was compared in a double-blind crossover study. Thirty-six healthy subjects were exposed to motion three times for 90 min in a ship-motion simulator. Transdermal applications were made and tablets were taken at least 12 and 2 hr before exposure to motion. Transdermal scopolamine provided better protection than placebo or meclizine. Dryness of mouth was the only side effect reported more frequently for one regimen, transdermal scopolamine.

Administration, Oral↗
PubMed1993

Effects of systemic indomethacin, meclizine, and BW755C on chronic ultraviolet B-induced effects in hairless mouse skin.

Chronic exposure of hairless mice to ultraviolet B (UVB) radiation is associated with inflammation as well as an altered macromolecular composition of the dermis. This study was designed to determine whether or not various systemic anti-inflammatory agents inhibit chronic UVB-induced changes in the macromolecular content of the dermis and, if so, whether each agent had the same or different effects. The agents and doses were chosen for their ability to inhibit the changes induced by a single exposure to UVB radiation (increased vasopermeability, neutrophil accumulation, and skin-fold thickness). Indomethacin, a cyclooxygenase inhibitor, and meclizine, an H1 histamine receptor antagonist, were administered from slow-release pellets. BW755C, a combined cyclooxygenase and lipoxygenase inhibitor, was administered intraperitoneally 30 min prior to UVB exposure. Animals were exposed to UVB three times per week for 20-26 weeks or were unirradiated. The elastin, glycosaminoglycan and collagen content of the skin were determined by measuring the desmosine, uronic acid, and hydroxyproline levels, respectively. The amount of each macromolecule per area of skin increased after chronic UVB exposure. The increase in desmosine was inhibited by indomethacin; the increase in hydroxyproline was inhibited by meclizine and BW755C. None of the agents inhibited the uronic acid increase. These results suggest that chronic inflammation contributes to the dermal changes seen in chronically UVB-exposed skin and that different inflammatory mediators are involved in the increases observed in elastin, glycosaminoglycans, and collagen.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1978

Comparative investigation between thiethylperazine and meclizine in vertigo of different genesis.

Forty patients suffering from vertigo of different genesis received thiethylperazine 6.5 mg or meclizine 25 mg, 2 capsules a day for 5 days, according to double-blind, cross-over methodology in randomized order. It appeared that the effect on the symptoms vertigo, gait disturbance and nausea does not differ significantly for the two preparations. On the other hand, an almost significant effect on vertigo, and, to a smaller degree, on gait disturbances, was obtained during the second period of treatment, independent of administered preparation. Side-effects in the form of fatigue and headache occur to the same extent after both preparations. Meclizine should be an alternative to thiethylperazine in the treatment of vertigo, especially in patients who might risk chronic dyskinesia in long-term treatment.

Adult↗
PubMed1963

Teratogenic effects of meclizine hydrochloride on the rat.

Congenital malformations were induced in the offspring of pregnant Sprague-Dawley rats by the admninistration of relatively large doses of meclizine hydrochloride (Bonine). The critical period of gestation for administration was from the 12th to 15th day. Anomalies were produced in the tongue, palatal closure, mouth, lower jaw, vertebrae and limbs.

Animals↗
PubMed2006

Induction of apoptosis and cell-cycle arrest in human colon cancer cells by meclizine.

Meclizine (MEC), a histamine H1 antagonist, is used for the treatment of motion sickness and vertigo. In this study, we demonstrate that MEC dose-dependently induced apoptosis in human colon cancer cell lines (COLO 205 and HT 29 cells). Results of a DNA ladder assay revealed that DNA ladders appeared with MEC treatment in COLO 205 cells at dosage of >50 microM. In addition, the total cell number decreased dose-dependently after treatment with MEC in COLO 205 and HT 29 cells. Using flow cytometry, the percentage of COLO 205 cells arrested at G0/G1 phase increased dose-dependently. Analysis of changes in cell-cycle arrest-associated proteins with Western blotting showed that p53 and p21 were upregulated after treatment with MEC. The kinase activities of cyclin-dependent kinase 2 (CDK2) and CDK4 were suppressed in MEC-treated cells. As for apoptosis, MEC may induce upregulation of p53 and downregulation of Bcl-2, thus causing the release of cytochrome C from mitochondria and the translocation of apoptosis-inducing factor (AIF) to the nucleus. This resulted in the activation of caspase 3, 8, and 9. Our results provide the molecular basis of MEC-induced apoptosis and cell-cycle arrest in human colon cancer cells.

Apoptosis↗
PubMed1999

Cleaning level acceptance criteria and a high pressure liquid chromatography procedure for the assay of Meclizine Hydrochloride residue in swabs collected from pharmaceutical manufacturing equipment surfaces.

A method using pharmacologically based and visual limit of detection criteria to determine the acceptable residue level for Meclizine Hydrochloride (MH) on pharmaceutical manufacturing equipment surfaces after cleaning is described. A formula was used in order to determine the pharmacologically safe cleaning level for MH. This level was termed as specific residual cleaning Level (SRCL) and calculated to be 50 microg 100 cm(-2). The visual limit of detection (VLOD) was determined by spiking different levels of MH on stainless steel plates and having the plates examined by a group of observers. The lowest level that could be visually detected by the majority of the observers, 62.5 microg 100 cm(-2), was considered as the VLOD for MH. The lower of the SRCL and VLOD values, i.e. 50 microg 100 cm(-2), was therefore chosen as the cleaning acceptance criterion. A sensitive reversed-phase HPLC method was developed and validated for the assay of MH in swabs used to test equipment surfaces. Using this method, the mean recoveries of MH from spiked swabs and '180-Grit' stainless steel plates were 87.0 and 89.5% with relative standard deviations (RSD) of +/- 3.3 and +/- 2.4%, respectively. The method was successfully applied to the assay of actual swab samples collected from the equipment surfaces. The stability of MH on stainless steel plates, on cleaning swabs and in the extraction solution was investigated.

Antiemetics↗
PubMed1986

Plasmodium berghei-infected mice: lack of effect of meclizine and cimetidine on the development of pulmonary oedema.

The involvement of histaminergic mechanisms in the pathogenesis of pulmonary oedema observed in Plasmodium berghei-infected mice was investigated. Histamine concentrations in plasma and whole blood of infected and normal mice were determined by radioenzymatic assay during the seven days of the infection. Elevated plasma and whole blood histamine levels were found at the last stages of infection (sixth day and seventh day after ip injection of parasitized erythrocytes), showing a close temporal correlation between the development of oedema and the elevation of the circulating histamine concentrations. However, the treatment of infected mice with the H1- or H2-receptor antagonists, meclizine or cimetidine, did not change the development of pulmonary oedema. The absence of effects of H1- and H2-receptor blockers on this model is a suggestive evidence that histamine does not contribute to P. berghei-induced pulmonary oedema in mice.

Animals↗
PubMed1989

[Dissolution and absorption behavior of meclizine dihydrochloride from soft gelatin capsules].

Two kinds of soft gelatin capsules containing meclizine dihydrochloride (MZ) were prepared by using a medium-chain length triglyceride as a base. One is a self-emulsifying type, and the other is an oil dispersing type. The release of MZ from soft capsules and its in vivo absorption behavior were examined and compared with those of a commercial tablet. The release of MZ from the self-emulsifying soft capsule which was only slightly affected by pH was greater than those from the oil dispersing soft capsule and commercial tablet. The serum levels of MZ after the administration of preparations orally to beagle dogs increased in the order of self-emulsifying soft capsule, commercial tablet, oil dispersing soft capsule. This result suggests that the self-emulsifying soft capsule is useful for the increase of the bioavailability of the drug.

Administration, Oral↗