Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new antivert research articles will be listed here shortly after becoming available to us.
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Medical research on antivert
Vertigo - part 2 - management in general practice.
Aust Fam Physician. 2008 Jun; 37(6): 409-13
Kuo CH, Pang L, Chang R
BACKGROUND: Vertigo is a common clinical problem managed by general practitioners. OBJECTIVE: This article focuses on the acute management of a vertigo attack, specific management of conditions causing vertigo, and the long term management issues associated with chronic vertigo. DISCUSSION: Supportive treatment, antiemetic and vestibular blocking agents help relieve an acute vertigo attack, however the prolonged use of such medications is not recommended. Specific treatments for various conditions causing vertigo are available, however, the majority of patients are managed symptomatically. The patient's ability to drive safely should be carefully assessed according to Austroads guidelines and advice from an ear, nose and throat surgeon should be sought when in doubt. There is evidence to support the efficacy of vestibular rehabilitation programs for unilateral peripheral vestibular disorder and these programs should be considered. A simple program including patient education and home based exercises can be sufficient.
Treating common ear problems in pregnancy: what is safe?
Eur Arch Otorhinolaryngol. 2008 Feb; 265(2): 139-45
Vlastarakos PV, Nikolopoulos TP, Manolopoulos L, Ferekidis E, Kreatsas G
In everyday practise, more than 80% of pregnant women receive one at least medication, often for ENT causes. The aim of the present paper is to review the literature on safety and administration of medical treatment for ear diseases, in pregnant women. The literature review includes Medline and database sources. Electronic links, related books and written guidelines were also included. The study selection was as follows: controlled clinical trials, prospective trials, case-control studies, laboratory studies, clinical reviews, systematic reviews, metanalyses, and case reports. The following drugs are considered relatively safe: beta-lactam antibiotics (with dose adjustment), macrolides (although the use of erythromycin and clarithromycin carries a certain risk), and acyclovir. Non-selective NSAIDs (until the 32nd week), nasal decongestants (with caution and up to 7 days), intranasal corticosteroids, with budesonide as the treatment of choice, first generation antihistamines, or cetirizine (third trimester) and loratadine (second and third trimester) from the second generation, H2 receptor antagonists (except nizatidine) and proton pump inhibitors (except omeprazole), can be used to relieve patients from the related symptoms. Meclizine and dimenhydrinate, as antiemetics in vertigo attacks; metoclopramide, vitamin B6 and ginger rhizome, alternatively. Low-dose diazepam and diuretics in severe cases of Meniere's disease (with caution). Systemic administration of prednisone and prednisolone can be considered in selected cases. By contrast, selective COX-2 inhibitors, betahistine and vasodilating agents are contraindicated in pregnancy. Since otologic and neurotologic manifestations during pregnancy tend to seriously affect the quality of life of the expectant mothers, ENT surgeons should familiarise themselves with the basic guidelines and safety precautions for any related medication, in order to provide appropriate treatment.
Clin Cancer Res. 2007 Sep 15; 13(18 Pt 1): 5488-96
Christov K, Grubbs CJ, Shilkaitis A, Juliana MM, Lubet RA
PURPOSE: The methylnitrosourea (MNU)-induced mammary cancer model in rats is similar to estrogen receptor-positive breast cancer in women. In prevention studies using this model, tumor incidence and multiplicity were typically primary end points. The ability of various agents administered for a short period to modulate cell proliferation [proliferation index (PI)] and apoptosis [apoptotic index (AI)] in mammary cancers was compared with their efficacy in long-term prevention and therapy studies. EXPERIMENTAL DESIGN: Rats were injected with MNU to induce mammary cancers. For the prevention studies, agents were administered by gavage or in the diet beginning 5 days after MNU. For proliferation (PI) and apoptosis (AI) experiments, animals with a palpable mammary cancer were treated with the agents for only 4 to 7 days. PI was determined following 5-bromodeoxyuridine labeling whereas AI was determined using the terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling assay. Therapeutic efficacy was evaluated by measuring cancer size over a 6-week period. RESULTS: Treatments with differing chemopreventive efficacy and mechanism(s) of action were examined: (a) hormonal treatments [tamoxifen, vorozole (an aromatase inhibitor), and ovariectomy]; (b) retinoid X receptor agonists (targretin, 9-cis retinoic acid, and UAB30); (c) inducers of drug-metabolizing enzymes (indole-3-carbinol, 5,6 benzoflavone, and diindoylmethane); (d) agents that alter signal transduction (R115777, a farnesyltransferase inhibitor); Iressa (an epidermal growth factor receptor inhibitor); sulindac and celecoxib (cyclooxygenase 1/2 and cyclooxygenase 2 inhibitors); and (e) diverse agents including meclizine, vitamin C, and sodium phenylbutyrate. Correlations between inhibition of PI, increase of AI, and chemopreventive efficacy were observed. Although most agents with moderate or low preventive efficacy suppressed PI, they minimally affected AI. CONCLUSIONS: The data confirmed that the short-term effects of various agents on cell proliferation and apoptosis in small mammary cancers can predict their preventive/therapeutic efficacy. Thus, these biomarkers can be used to help determine the efficacy of compounds in phase II clinical prevention trials.
Airsickness prevention in helicopter passengers.
Aviat Space Environ Med. 2007 Apr; 78(4): 408-13
Estrada A, LeDuc PA, Curry IP, Phelps SE, Fuller DR
INTRODUCTION: Despite many existing treatments, airsickness is an issue of concern for soldiers being transported by helicopter. This experiment examined the efficacy of four airsickness treatments and their effects on performance. This study replicated the transport of soldiers in the cabin of an UH-60 Black Hawk helicopter performing many of the flight maneuvers potentially experienced in a night troop transport during turbulent conditions. METHODS: A double-blinded, placebo-controlled design was used to compare the effectiveness of four airsickness countermeasures to their placebo controls. There were 64 male, non-aviator subjects (ages 18-34 yr) who were recruited for the study. Of these, 16 subjects were randomly assigned to each of 4 groups: (1) promethazine (25 mg) + caffeine (200 mg); (2) meclizine (25 mg); (3) Scopolamine patch (1.5 mg); and 4) acustimulation wristband. Each individual participated twice, once with the treatment and once with placebo. RESULTS: The findings indicated that only the combination of promethazine + caffeine showed a statistically significant reduction in nausea and motion sickness severity, and an improvement in reaction time when compared with its placebo control. DISCUSSION: Data from this study indicated that of the countermeasures tested, promethazine + caffeine was the most effective at reducing airsickness while producing the fewest side effects when compared with its placebo. In addition, this study demonstrated that over-the-counter caffeine can serve as an effective stimulant counterpart to promethazine. This may be a more appealing option than employing scheduled sympathomimetic drugs in a combat environment.
Pak J Pharm Sci. 2007 Apr; 20(2): 149-56
Arayne MS, Sultana N, Siddiqui FA, Zuberi MH, Mirza AZ
Three new spectrophotometric procedures for the simultaneous determination of pyridoxine hydrochloride and meclezine hydrochloride are described. The first method depends on the application of simultaneous equation to resolve the interference due to spectral overlapping. The analytical signals were measured at 231 and 220 nm. Calibration graphs were established for 1 to 20 microGmL(-1) for pyridoxine hydrochloride and 0.5 to 10 microGmL(-1) for meclezine hydrochloride in binary mixture. In the second method, the determination of pyridoxine hydrochloride and meclezine hydrochloride was performed by measuring the absorbances at 290 and 235 nm in the simple absorbance spectra of their mixture. In third method a yellowish orange complex of pyridoxine hydrochloride was formed with ferric chloride, which absorbs in the visible region with lambda(max) at 445 nm. Calibration curve of complex formation range was conducted in between 20 to 250 microGmL(-1). These methods were validated with respect to accuracy, precision, linearity, limit of detection and quantification. Regression analysis of Beer's plot showed good correlation in a general concentration range of 1 to 20 microGml(-1) with correlation coefficient (r = 0.9999 and 0.9999; CV < 0.858) for pyridoxine hydrochloride, whereas meclezine hydrochloride concentration range 0.5 to 10 microGmL(-1) with correlation coefficient (r = 0.9998 and 0.9998; CV < 0.826). These methods can be readily applied, without any interference from the excipients. The suggested procedures were successfully applied to the determination of these compounds in synthetic mixtures and in pharmaceutical preparations, with high percentage of recovery, good accuracy and precision.
AANA J. 2007 Feb; 75(1): 27-33
Forrester CM, Benfield DA, Matern CE, Kelly JA, Pellegrini JE
Postoperative nausea and vomiting (PONV) is prevalent in surgical patients with known risk factors: general anesthesia, female, nonsmoker, motion sickness history, and PONV history. Common treatment involves ondansetron; however, the effects are short-lived, and supplemental medication may be required. Meclizine, a long-acting drug with a low side-effect profile, may be ideal in combination with ondansetron for at-risk patients. We randomized 77 subjects scheduled for general anesthesia and screened for 4 of 5 PONV risk factors for experimental or control group assignment. Severity of PONV was measured using a 0 to 10 verbal numeric rating scale (VNRS). Other measured variables included time to onset and incidence of PONV and total antiemetic requirements. No significant differences in demographics (excluding weight), surgical or anesthesia time, analgesic requirements, or nausea incidence in the postanesthesia care unit (PACU) and same-day surgery unit were noted. The meclizine group had lower VNRS scores in the PACU at 15 (P = .013) and 45 (P = .006) minutes following rescue treatment. The incidence of nausea was lower in the meclizine vs. placebo group (10% vs. 29%) following discharge (P = .038). Prophylactic meclizine resulted in lower incidence and severity of PONV in a high-risk population, especially after rescue treatment.
Induction of apoptosis and cell-cycle arrest in human colon cancer cells by meclizine.
Food Chem Toxicol. 2007 Jun; 45(6): 935-44
Lin JC, Ho YS, Lee JJ, Liu CL, Yang TL, Wu CH
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.
Inflamm Res. 2006 Dec; 55(12): 559-64
Alencar NM, Oliveira JS, Mesquita RO, Lima MW, Vale MR, Etchells JP, Freitas CD, Ramos MV
OBJECTIVES AND DESIGN: Previous studies have described pro- and anti-inflammatory activities displayed by the latex from Calotropis procera. This report aims to clarify these observations and shows that such activities can be segregated from the whole latex. METHODS: The latex was divided into water-soluble fractions devoid of poly-isoprene by centrifugation and dialysis and both the activities were assayed by the peritonitis model in rats. The drugs dexamethasone, thalidomide, meclizine, indomethacin and celecoxib were used to modulate the inflammatory stimuli. RESULTS: Inflammation in rats was observed 2 h after intraperitoneal administration of the stimulus (DL fraction) in a dose dependent manner. This activity was inhibited by previous intravenous injection of dexamethasone, thalidomide and meclizine. Indomethacin and celecoxib did not reverse inflammation. These results suggest the involvement of histamine release and TNF-alpha mediated inflammation while prostaglandins seem not to be required. The anti-inflammatory fraction (NDL) inhibited inflammation triggered by proinflammatory fraction (DL) suggesting that NDL ought to follow a similar pathway of action to that of the anti-inflammatory drugs that were able to inhibit inflammation triggered by DL. CONCLUSIONS: Pro- and anti-inflammatory activities of the latex are displayed by compounds suitable to be fractionated on the basis of their molecular size.
Toxicon. 2006 Jun 15; 47(8): 885-93
Bonavita AG, da Costa AS, Pires AL, Neves-Ferreira AG, Perales J, Cordeiro RS, Martins MA, e Silva PM
Bothrops jararaca venom (Bjv) is known to induce local inflammation and severe pain. Since, mast cells are able to secrete mediators involved in algesic processes, in this study we examined the putative role of these cells in the hyperalgesia triggered by Bjv in the rat paw. We noted that treatment with mast cell stabilizer sodium cromoglicate as well as with histamine and 5-hydroxytriptamine receptor antagonists meclizine and methysergide, respectively, inhibited the Bjv-induced hyperalgesia. In addition, we showed that stimulation of isolated rat peritoneal mast cells with Bjv in vitro resulted in the release of stored and neo-generated inflammatory mediators such as histamine and leukotriene C(4), respectively. Bjv-induced histamine secretion was clearly sensitive to treatment with sodium cromoglicate and sodium nedocromil. We further observed that metalloproteinase inhibitors 1,10-phenantroline and DM43 inhibited mast cell degranulation in vitro, under conditions where inhibitors of phospholipase A(2) as well as of serine- and cysteine-proteinases were inactive. Altogether, our findings indicate that mast cells seem to contribute to the hyperalgesia caused by Bjv in the rat paw, and also provide evidence that this response might be dependent on the ability of the Bjv to activate directly mast cells.
Clin Pharmacokinet. 2006; 45(6): 543-66
Nachum Z, Shupak A, Gordon CR
A transdermal therapeutic system for scopolamine (TTS-S) was developed to counter the adverse effects and short duration of action that has restricted the usefulness of scopolamine when administered orally or parenterally. The plaster contains a reservoir of 1.5 mg of scopolamine programmed to deliver 0.5 mg over a 3-day period. A priming dose (140 microg) is incorporated into the adhesive layer to saturate certain binding sites within the skin and to accelerate the achievement of steady-state blood levels. The remainder is released at a constant rate of approximately 5 microg/hour. The protective plasma concentration of scopolamine is estimated to be 50 pg/mL. TTS-S attains that concentration after 6 hours; a steady state of about 100 pg/mL is achieved 8-12 hours after application. Yet 20-30% of subjects failed to attain the estimated protective concentration, and plasma concentrations measured in subjects who failed to respond to TTS-S were lower than in responders. These findings may explain some of the treatment failures. Overall, the product appears to be the approximate functional equivalent of a 72-hour slow intravenous infusion. A combination of transdermal and oral scopolamine (0.3 or 0.6 mg) was effective and well tolerated in producing desired plasma concentrations 1-hour post-treatment. TTS-S has proved to be significantly superior to placebo in reducing the incidence and severity of motion sickness by 60-80%. It was more effective than oral meclizine or cinnarizine, similar to oral scopolamine 0.6 mg or promethazine plus ephedrine, and the same as or superior to dimenhydrinate. The addition of ephedrine or the use of two patches did not improve its efficacy, but rather increased the rate of adverse effects. TTS-S was most effective against motion sickness 8-12 hours after application. Despite previous evidence to the contrary, a recent bioavailability study demonstrated similar intraindividual absorption and sustained clinical efficacy with long-term use of the drug. The adverse effects produced by TTS-S, although less frequent, are qualitatively typical of those reported for the oral and parenteral formulations of this agent. Dry mouth occurs in about 50-60% of subjects, drowsiness in up to 20%, and allergic contact dermatitis in 10%. Transient impairment of ocular accommodation has also been observed, in some cases possibly the result of finger-to-eye contamination. Low-dose pyridostigmine was found effective in preventing cycloplegia but not mydriasis. Adverse CNS effects, including toxic psychosis (mainly in elderly and paediatric patients), have been reported only occasionally, as have difficulty in urinating, headache, rashes and erythema. Adverse effects were not correlated with plasma scopolamine concentrations. TTS-S produced only about half the incidence of drowsiness caused by oral dimenhydrinate or cinnarizine, and a level of adverse effects similar to that found with oral meclizine. Performance is not affected by short-term use. Prolonged or repeated application may cause some impairment of memory storage for new information. However, sea studies revealed significantly less reports of a decrement in performance or drowsiness due to prevention of sea sickness. The recommended dosage is a single TTS-S patch applied to the postauricular area at least 6-8 hours before the anti-motion sickness effect is required. For faster protection, the patch may be applied 1 hour before the journey in combination with oral scopolamine (0.3 or 0.6 mg). After 72 hours, the patch should be removed and a new one applied behind the opposite ear. Its place in therapy is mainly on long journeys (6-12 hours or longer), to avoid repeated oral doses, or when oral therapy is ineffective or intolerable.