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Results for “Nikethamide”

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At least 19 recordsLinked to original sources

PubMed1989

Potentiation of cathinone by caffeine and nikethamide.

The drug discrimination paradigm was employed to evaluate the effect of coadministration of both caffeine and nikethamide upon the discrimination of a low dose of cathinone. In rats trained to discriminate between 0.8 mg/kg l-cathinone and its vehicle in a two-lever food-motivated operant task, 0.2 mg/kg cathinone produced 29.2% of responses on the cathinone-appropriate lever. This lever was chosen in 0 and 50% of trials with 25 mg/kg nikethamide and 20 mg/kg caffeine, respectively. Coadministration of caffeine, nikethamide, or caffeine plus nikethamide with low-dose cathinone produced strong cathinone-like discriminative performance. This potentiattion of cathinone by caffeine and nikethamide is reflective of noncontrolled drugs of abuse containing similar combinations especially for that of antiadipositum X-112, a drug containing all three agents and widely abused in Europe.

Alkaloids↗

PubMed1984

The effect of solvent polarity upon rotational barriers in nikethamide.

In summary, dynamic nuclear magnetic resonance techniques were used to study the hindered internal rotation of the amide bond of the analeptic nikethamide. The rotatory motion of this bond was studied in a series of solvents of increasing polarity: CDCl3, CH3(CH2)3OD, CH3CH2OD, CH3OD and D2O. Motion about the amide bond was increasingly hindered in direct proportion to solvent polarity, correlating with enhanced hydrogen bond formation between nikethamide and the more polar solvent molecules. Diethylamide group motion would be expected to affect binding of the carbonyl oxygen to cholinergic receptor sites. The degree to which association to a receptor site can be affected by this rotatory motion may vary from 0 to 4 kcal/mole, the variability being entirely dependent upon the polarity of the binding site. An increase in rotamer lifetime, corresponding to a more polar environment, would be expected to enhance the kinetics of nikethamide association to the receptor site.

Animals↗

PubMed1976

Excretion and metabolism of nikethamide in the horse.

It is well known that nikethamide (N,N-diethylnicotinamide, CoramineR) is metabolized very rapidly to nicotinamide. Hence, there is difficulty in proving that nikethamide has been used as a doping substance because nicotinamide is a normal physiological metabolite in the organism as well as a vitamin preparation. However, an intermediate metabolite (N-ethylnicotinamide) was found by us in the urine of horses treated with CoramineR. This was characterized by gas chromatography/mass spectrometry, and synthesized and identified as being N-ethylnicotinamide. The excretion and metabolism of nikethamide after intramuscular injection in the horse was followed using quantitative gas chromatography of urine extracts over a period of several hours and the results of these experiments are reported. Changes in urinary pH had no significant effect upon either the metabolism or rate of excretion of the drug.

Ammonium Chloride↗

PubMed1993

[Effects of oxygen and nikethamide on central drive, ventilation and blood gases of patients with obstructive lung disease in acute exacerbation of respiratory failure].

Twelve subjects with COPD in acute exacerbation of respiratory failure were studied. The experiment of each subject was divided into three steps: room air breathing, 35% O2 inhalation for one hour, and then intravenous drip of nikethamide (1.875g) for two hours with 35% oxygen inhalation at the same time. At the end of each step, mouth occlusion pressure (P0.1), VT, VE, VA, VCO2, VD and PaO2, PaCO2 were measured respectively. The results showed that, when breathing air, all the patients presented significant higher P0.1 than normal subjects, indicated higher central drive. After oxygen inhalation, P0.1 decreased markedly, but still higher than normal. No correlation was found between delta P0.1 and delta PaO2. VE declined with the drop of P0.1, but this was due to a decrease of respiratory frequency, while VA remained unchanged (P > 0.05). The increase of PaCO2 was unremarkable. Neither correlation was found between delta VA and delta P0.1, nor between delta VA and delta PaCO2. However, a close correlation existed between delta VCO2/VCO2 and delta VE/VE. The result of our study is not consistent with the postulation, the removal of the hypoxic stimulate after oxygen administration results in a decrease of ventilation and CO2 retention. After nikethamide administration, P0.1 increased as well as VE while VA and PaCO2 remained unchanged. The increase of VE was caused by the increase of respiratory rate. Furthermore, PaO2 decreased in some patients. All of the changes demonstrated that nothing is worthwhile with the treatment of nikethamide, but a side effect from increasing work of breathing and consumption of oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Solvent dependency of rotational barriers in ethamivan and comparison to nikethamide.

Carbon-13 nuclear magnetic resonance (NMR) techniques were employed to examine the effects of solvent environment on rotational barriers in two drugs known to cause widespread stimulation in the mammalian central nervous system: ethamivan and nikethamide. Total NMR bandshape analysis was performed for the exchanging alkyl carbon resonances of these compounds as a function of temperature in six solvent systems: D2O, CH3OD, CH3CH2OD, CDCl3, C6D6 and CF3CH2OH. The rate constants for rotation about the amide bond obtained in this way were used to calculate free energy (delta G++), enthalpy (delta H++) and entropy (delta S++) of activation parameters for this process. Our results indicate that the magnitude of rotational barriers is affected markedly by (1) the size and polarity of the solvent molecules, and (2) the nature of the aromatic ring system attached to the amide grouping. Comparative interpretation of the thermodynamic parameters in light of the structures of nikethamide and ethamivan (in the various solvent systems examined) has further clarified the manner in which hydrogen bonding interactions between solvent molecules and the carbonyl oxygen of these analogues stabilize transition state conformers.

Acetonitriles↗

PubMed1979

Determination of nikethamide and N-ethylnicotinamide in the blood and urine of greyhounds.

Following the intramuscular administration of nikethamide to a series of greyhounds, both plasma and urine excretion levels were obtained. A qualitative urine screening procedure for both nikethamide and its major metabolite has been devised. The method involves solvent extraction, thin-layer and a two-system gas chromatographic system.

Animals↗

PubMed1976

Gas-liquid chromatographic determination of nikethamide in injectable preparations.

A gas-liquid chromatographic (GLC) method, using a 4% XE-60 on 80-100 mesh Gas-Chrom Q column, a flame ionization detector, and anthracene as the internal standard, has been developed for the direct determination of nikethamide. Eight collaborators analyzed 4 samples, using methanol as the solvent; the coefficients of variation obtained ranged from 1.19 to 3.20%. In a limited study with acetone as the solvent, the coefficients of variation ranged from 0.59 to 1.96%. The GLC method with acetone as a solvent has been adopted as official first action.

Chromatography, Gas↗

PubMed1981

[Studies on the reaction of plastics with drug solutions. Part 2: Nikethamide (author's transl)].

The authors describe the effects of nikethamide solutions of varying concentrations on natural-coloured and red-coloured low-density polyethylene. For this purpose, they analyse the findings from stress-crack studies performed by means of a test method previously described [6,7]. The results obtained lead to a new interpretation of pharmaceutical ageing under the given conditions.

Chemical Phenomena↗

PubMed1994

[Pharmacokinetics and pharmacodynamics of nikethamide after endotracheal administration in dogs].

Five dogs were anaesthetized by using i.v. 30 mg.kg-1 Na-pentobarbiturate. For each dog, the tracheostomy was done and a sterized rubber tube was inserted into the tracheal tract. Through the rubber tube, 10 ml sterized nikethamide (Nik) solution was rapidly injected into the tract via 10 ml syringe and 5 forceful ventilations were performed immediately with the aid of a balloon in 30 s. Following tracheal administration (ET) of Nik 8.3 or 25 mg.kg-1 in dogs the pharmacokinetics and pharmacodynamics were studied. Blood Nik concentrations were determined by phosphorimetric method. It was shown that the absorption of Nik via tracheal tract was very quick. The blood Nik levels were 7.9 and 10.6 micrograms.ml-1 at 0.5 min and reached the maxima of 12.8 and 31.9 micrograms.ml-1, at 2.5 min, respectively, which was higher than that of i.v. Nik 8.3 mg.kg-1. Time course of Nik concentrations in plasma after ET 8.3 and 25 mg.kg-1 were fitted to a 2-compartment open model with T1/2Ka 0.48 and 0.85 min, T1/2 alpha 2.37 and 1.68 min, T 1/2 beta 114 and 130 min, AUC 1201 and 2790 micrograms.min.ml-1, bioavailability 84.7% and 65.5%, respectively. One minute after i.v. or ET Nik (8.3 or 25 mg.kg-1), respiration rate and tidal volume were increased and reached the maxima after 5 min. The recovery of respiration rate and tidal volume were proportional to the blood Nik concentration after 5-45 min with a linear regression coefficient of 0.9. The results indicated that ET Nik may be used instead of i.v. in resuscitation.

Animals↗

PubMed1975