Effect Of Chlorpheniramine Research Articles

Sedative Effect of Chlorpheniramine in Children Failed to sedate with Chloral hydrate and Midazolam

Sedative Effect of Chlorpheniramine in Children Failed to sedate with Chloral hydrate and Midazolam

Chlorpheniramine exerts anxiolytic-like effects and activates prefrontal 5-HT systems in mice

The traditional antihistamine chlorpheniramine ameliorates panic attacks, phobias, and lowered mood, and this therapeutic effect is independent of the blockade of histamine H(1) receptors. Since chlorpheniramine inhibits the reuptake of serotonin (5-HT), the anxiolytic-like effect of chlorpheniramine may be produced by an increase in serotonergic function. To elucidate the mechanisms underlying the anxiolytic-like effects of chlorpheniramine in mice, we examined the involvement of 5-HT systems in the prefrontal cortex that is a crucial region in the regulation of emotional function. Chlorpheniramine (0.05-5 mg/kg, i.p.) dose-dependently and significantly decreased the duration of freezing behavior in both the elevated open-platform and conditioned fear tests. The anti-freezing effects of chlorpheniramine (5 mg/kg, i.p.) in these tests were inhibited by pretreatment with the non-selective antagonist at 5-HT receptors, methiothepin (0.01 mg/kg, s.c.). In addition, the local injection of chlorpheniramine (10-100 ng/mouse) and 5-HT (1-10 μg/mouse) into the medial part of the prefrontal cortex (mPFC) dose-dependently and significantly decreased the duration of freezing behavior in the elevated open-platform test. In a microdialysis study, chlorpheniramine (0.5 and 5 mg/kg, i.p.) dose-dependently and significantly increased the extracellular 5-HT level in the mPFC. In addition, the local perfusion of chlorpheniramine (10 and 30 μM), but not of the selective H1 receptor antagonist, cetirizine, into the mPFC markedly increased the extracellular 5-HT level in the mPFC. The anxiolytic-like effect of chlorpheniramine is produced, at least in part, by the facilitation of serotonergic neurotransmission in the PFC.

Effect of chlorpheniramine on the pharmacokinetics of and response to chloroquine of Nigerian children with falciparum malaria

Chlorpheniramine (CP), a histamine H 1-receptor antagonist, enhances the efficacy of chloroquine (CQ) in acute uncomplicated falciparum malaria. The effects of this combination therapy on the pharmacokinetic disposition of CQ is, however, unpredictable. A standard treatment with 25 mg CQ base per kg bodyweight was orally administered over 3 days, alone or in combination with CP, to 17 semi-immune Nigerian children with Plasmodium falciparum parasitaemia attending hospital in Lagos, Nigeria, and observed for 28 days. Whole-blood CQ concentrations were monitored 14 times during the follow-up by high-performance liquid chromatography analysis of blood dried on filter paper. Parasitaemia was determined on thick blood films stained with Giemsa, and treatment failures were established following the WHO classification for CQ resistance. Our pharmacokinetic data showed that the peak whole-blood CQ concentration was significantly increased ( P < 0·05) by CP administration, and the time to achieve the peak was reduced in the presence of CP. The area under the first-moment drug-concentration-time curve was also significantly increased ( P < 0·05) by CP administration. Treatment with CQCP combination resulted in a shorter parasite clearance time (2·0 ± 0·5 days) and a higher cure rate (87·5%) compared to treatment with CQ alone (3·5 ± 0·5 days; 66·7%). Our data suggest that CP enhanced the efficacy of CQ against resistant P. falciparum in acute uncomplicated malaria by increasing the uptake/concentration of CQ in resistant parasites.

Effect of Chlorpheniramine on Airway Physiology and Symptoms during Natural Pollen Exposure

Previous studies have documented the changes in airway physiology which accompany natural pollen exposure. This study was designed to determine the effect of chlorpheniramine (8 mg b.i.d.) on seasonal changes in airway physiology and symptoms. Pollen counts, eustachian tube (ET) function, nasal resistance, mucociliary transport, and nasal symptoms were assessed weekly before, during, and after ragweed pollen season in 15 chlorpheniramine-treated and 15 placebo-treated allergic rhinitis (AR) subjects in a double-blind protocol and in 10 untreated control (non-AR) subjects. In placebo-treated AR subjects, the degree of congestion, rhinorrhea, sneezing, ET dysfunction, and nasal obstruction closely tracked pollen counts. However, symptoms, ET obstruction, and nasal obstruction persisted well beyond the temporal peak in pollen counts. There were no changes in mucociliary transport or pulmonary function during pollen exposure. Compared to placebo, chlorpheniramine-treated subjects manifested significantly less (p &lt; .05) seasonal sneezing and rhinorrhea, but similar degrees of nasal congestion, ET dysfunction, and nasal obstruction. Pollen-related changes in nasal physiology and symptoms were not detected in the non-AR subjects. These data document that chlorpheniramine significantly attenuated the seasonal increases in rhinorrhea and sneezing, but did not lessen the concommitant physiologic alterations or the increase in nasal congestion.

The Effect of Chlorpheniramine on Asthma

Patients with stable asthma can tolerate antihistamines without any significant deleterious effects both on a short- and a long-term basis. In addition, patients with steroid-dependent asthma appear to tolerate antihistamines without any significant deleterious effects. Therefore, oral chlorpheniramine does not appear to have ill effects on patients with asthma. Warning labels required by the FDA for antihistamine use in asthmatics are unnecessary.

444 The long-term effect of chlorpheniramine on asthma

444 The long-term effect of chlorpheniramine on asthma

23 Effect of chlorpheniramine (C) vs placebo (P) on nose and ear function of atopic subjects before and after histamine nasal challenge

23 Effect of chlorpheniramine (C) vs placebo (P) on nose and ear function of atopic subjects before and after histamine nasal challenge

O-25 - Effect of chlorpheniramine on muricide induced by thiamine deficiency

O-25 - Effect of chlorpheniramine on muricide induced by thiamine deficiency

Effect of chlorpheniramine, promethazine and cimetidine on human sperm motility in-vitro.

Ni l'histamine, ni la cimetidine aux concentrations entre 1 et 10 mM n'ont produit de modification significative de la motilite des spermatozoides. Les deux antihistaminiques classiques: promethazine et allorpheniramine, ont provoque tous deux une reduction en rapport avec la dose de la motilite des spermatozoides, la promethazine etant le plus puissant. L'histamine s'est opposee a l'inhibiteur de la motilite induite par la promethazine

Histamine Receptors in Normal Human Bronchi

1. Nine normal subjects inhaled increasing concentrations of histamine aerosol from an aerosol generator attached to a breath-actuated dosimeter. The responses were monitored by measuring specific airways-conductance in a body plethysmograph, and the results were expressed as cumulative log dose-response curves. On separate days, histamine challenges were repeated after intravenous injections of sodium chloride solution (placebo), or an H1-receptor antagonist chlorpheniramine, or an H2-receptor antagonist cimetidine, or H1- and H2-receptor antagonists together. The anticholinergic activity of chlorpheniramine was estimated by comparing the effect of chlorpheniramine and atropine on methacholine challenge. 2. In all subjects the response to histamine was reproducible. Analysis of the variance showed that placebo did not alter the histamine dose-response curve significantly. In contrast, chlorpheniramine produced a large shift in the histamine dose-response curve to the right and cimetidine produced a significant shift of this curve to the right only at the highest dose of histamine. A combination of cimetidine and chlorpheniramine produced a shift not significantly different from that seen with chlorpheniramine alone. Chlorpheniramine showed no significant anticholinergic activity in this study. 3. In the normal subjects histamine-induced bronchoconstriction appeared to be mediated predominantly by the H1-receptors. The H2-receptor contributed very little to this bronchoconstriction.

The prevention of radiation-induced, early, transient incapacitation of monkeys by an antihistamine.

ConclusionsThe antihistamine chlorpheniramine maleate is effective in preventing ETI, postirradiation performance decrement, and in reducing the hypotension observed in monkeys after a 4000-rad dose of mixed gamma-neutron radiation. Since the major pharmacological effect of chlorpheniramine is blocking histamine receptor sites, its effectiveness in preventing or modifying the radiation-induced performance changes and hypotension can be taken as further evidence that histamine is involved in acute radiation syndrome. However, the ETI-ameliorating properties of chlorpheniramine are not mediated through the maintenance of arterial blood pressure. An earlier study (9) in which similarity trained and irradiated monkeys were infused with norepinephrine so that blood pressure was maintained above 100 mm Hg did not show significant differences in performance from controls. Some mechanism other than deficient blood pressure, yet capable of being ameliorated by chlorpheniramine, is implicated in ETI.

Pig atherosclerosis: Effect of the antihistamine, chlorpheniramine, on atherogenesis and serum lipids

Summary The antihistamine, chlorpheniramine, has been shown previously to inhibit cholesterol-induced rabbit atherosclerosis. The effect of chlorpheniramine has now been evaluated on the spontaneous atherosclerosis of uncastrated male minipigs. Three groups of pigs of 10 each were started at age 3 months on a nutritionally adequate diet containing 30 % by weight of lard to which was added either 0, 0.5 or 1.0 mg of chlorpheniramine/kg body weight. The animals were killed and autopsied at age 24 months. The aortas were stained with Sudan IV and graded on a basis of 0-4 + in the arch and abdominal areas. Atherosclerosis involvement was small in all groups; there were no significant differences although the 1.0-mg chlorpheniramine group had the least atherosclerosis. Chlorpheniramine appeared to increase the serum cholesterol levels while analysis of the fatty acid composition of the total serum lipids showed an increase in the percentage of 18:2 and decreases in 16:0 and 18:1.