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Comparison of efficacy of ginger with various antimotion sickness drugs.

Wood CD, Manno JE, Wood MJ, Manno BR, Mims ME.

Department of Pharmacology and Therapeutics, Louisiana State University Medical Center, Shreveport 71130.

Ginger and several other medications were compared with scopolamine and d-amphetamine for effectiveness in prevention of motion sickness. Methods: Double-blind techniques were used. The subjects were given the medications two hours before they were rotated in a chair making head movements until a symptom total short of vomiting was reached. Standardized N.A.S.A. techniques were used for speed of rotation and end-point of motion sickness. Results: The three doses of ginger were all at the placebo level of efficacy. Amitriptyline, ethopropazine and trihexyphenidyl increased the tolerated head movements but the increase was not statistically significant. Significant levels of protection were produced by dimenhydrinate, promethazine, scopolamine and d-amphetamine. Protection was further increased by combination of these latter drugs with d-amphetamine. Efficacy was greatest as the dose was increased. Conclusions: The medication of choice in this study was scopolamine 0.6 mg with d-amphetamine 10 mg. This combination provided good protection with acceptable side effects.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11538042&dopt=Abstract dimenhydrinate meclizine Antivert



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Spectrophotometric determination of dimenhydrinate with Reinecke salt.

Kar A, Aniuha GI.

A convenient spectrophotometric method was developed for the determination of dimenhydrinate in bulk drug and dosage forms and in 1:1 combinations with aspirin, acetaminophen, meprobamate, phenylephrine, and tolbutamide. The method consisted of reacting dimenhydrinate with reinecke salt in an acidic medium at 27 +/- 2 degrees. The purple precipitate was filtered and dissolved in acetone, and the maximum color absorption attained in 15 min was measured at 540 nm. Evidence is provided to establish the optimal experimental parameters. The stoichiometric balance of the precipitate was determined. Reasonably ideal adherence of the color absorption pattern to the Beer-Lambert law permitted microdetermination of dimenhydrinate in pure form, commercial formulations, laboratory-made combinations, and recovery experiments with good accuracy and repeatability. No interference was observed with any of the drugs or tablet adjuvants.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7252821&dopt=Abstract dimenhydrinate meclizine Antivert



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Structure-activity relationships of alkylamines that inhibit rat liver hydroxysteroid sulfotransferase activities in vitro.

Matsui M, Takahashi M, Miwa Y, Motoyoshi Y, Homma H.

Kyoritsu College of Pharmacy, Tokyo, Japan.

Tetraalkylammonium salts having n-propyl to n-amyl side chains inhibited rat liver sulfotransferase (ST) activities toward dehydroepiandrosterone and cortisol, but not ST activity toward 2-naphthol, whereas trialkylamines having ethyl to n-amyl side chains inhibited ST activity toward dehydroepiandrosterone, but not ST activities toward cortisol and 2-naphthol. A comparison of I50 values, which represent inhibitor concentration resulting in 50% inhibition of dehydroepiandrosterone ST activity, revealed that the values for the tetraalkylammonium salts were 0.015 to 0.017 mM, whereas the values for the trialkylamines were 0.20 to 0.33 mM. Introduction of hydrophilic groups such as hydroxyl, thiol, nitrile and acetamide groups or substitution by methyl and allyl groups in the alkyl side chains markedly diminished the inhibitory effect of triethylamine. These data indicate that ethyl to n-amyl side chains are a prerequisite for the alkylamine-type inhibitor. Tertiary amine drugs such as imipramine, dimenhydrinate, cyclizine, chlorpromazine and promethazine inhibited ST activities toward dehydroepiandrosterone and cortisol similar to the tetraalkylammonium salts, although the drugs were weaker inhibitors of hydroxysteroid ST activities. These results imply that in addition to trialkylamine side chains, the other portion of the drugs may participate in the inhibition of hydroxysteroid ST activities.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7887990&dopt=Abstract dimenhydrinate meclizine Antivert



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Effect of propylene glycol on the disposition of Dramamine in the rabbit.

Walters KM, Mason WD, Badr MZ.

University of Missouri-Kansas City 64108.

Dimenhydrinate (Dramamine) is the 8-chlorotheophylline salt of diphenhydramine. Dramamine is commercially available as a solution containing 50 mg dimenhydrinate per ml in 50% propylene glycol/5% benzyl alcohol. Studies in which New Zealand albino female rabbits received dimenhydrinate, i.v. and/or im, revealed evidence of inhibition of drug clearance apparently due to exposure to vehicle. Following im administration of 8-chlorotheophylline to naive rabbits, peak drug levels of 420 ng/ml were attained in 60 min which declined exponentially to near baseline levels within 7 hr. Animals treated with an additional im dose 2 days later achieved blood drug levels of > 2000 ng/ml which were sustained for the duration of the experimental period. Initial i.v. administration of 8-chlorotheophylline resulted in peak concentration of about 5000 ng/ml which declined to near baseline levels within 90 min, while 8-chlorotheophylline (i.v.) blood levels in rabbits exposed to im vehicle (2 days prior) appeared to plateau around 250 ng/ml after 60 min. Acute, short-term exposure to im vehicle did not appear to elicit the altered elimination profiles. An investigation of the influence of the recommended vehicle on the bioavailability and clearance of dimenhydrinate in isolated rabbit liver microsomes revealed that vehicle at concentrations > 0.68 mg/ml significantly decreased the percent of drug metabolized. This effect was directly proportional to the concentration of vehicle added. Studies showed this effect to be due to the propylene glycol component of the vehicle.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8097701&dopt=Abstract dimenhydrinate meclizine Antivert