No abstract available.
Antitussive Agents* ; Expectorants* ; Histamine Antagonists*

Histamine H1 Antagonists ; pharmacology ; Humans

This study was undertaken to observe the effects of centrally administred antihistamines on the blood pressure. Diphenhydramine(DPH), a H1-receptor antagonist, and ranitidine(RAN), a H2-receptor antagonist were administered intracerebroventricularly(icv) on urethane-anesthetized rabbits. 1) Both DPH and RAN administered intraccebroventricularly increased blood pressure, however the intravenous(iv) adminstration of them did not affect blood pressure. The pressor response to icv DPH was dose-dependent, but that to icv RAN was not. 2) The pressor response to icv DPH(1mg) was either markedly attenuated or reversed to depressor response by the pretreatment with icv phentolamine(250,500ug), and iv chlorisondamine(0.1, 1mg/Kg) and iv phenoxybenzamine(1mg/Kg). In cord-sectioned rabbtis, icv RAN) 1mg) did not produce pressor response. 3) The pressor responsr to icv RAN(1mg) was not affected by the pretreatment with icv phentolamine(500ug), iv chlorisondamin(1mg/Kg) and iv phenoxybenzamine(1mg/Kg), and iv phenoxybenzamine(1mg/Kg). RAN also producted pressor response in cordsectioned rabbits. These results suggest that the pressor response to icv DPH is elecited by increasing peripheral sympathetic tone via the stimulation of central alpha-adrenoreceptors and the pressor response to icv RAN is produced by releasing some humoral facotr which can increase blood pressure.
Blood Pressure ; Diphenhydramine* ; Histamine Antagonists ; Rabbits* ; Ranitidine*

Numerous drugs are known to cause seizures with therapeutic use or overdose. However, the relative frequency of such complications has rarely been studied, and little is known about the relationship of drug-induced seizures to eventual medical outcome. This study was performed to determine the causes and consequences of seizure associated with poisoning and drug intoxication. We analyzed about 786 cases of drug intoxication visited to Chung-Ang Gil hospital during recent 4 years from Jan. 1993 to Dec. 1996. The results were summarized as follows: 1. The total number of cases of drug intoxication was 786 and the most common drug of intoxication was antihistamines(291 cases, 36.3%); insecticides(113 cases, 14.7%); caustics(90 cases, 11.8%); herbicides(47 cases, 6.1%); NSAID(38 cases, 4.9%); rodenticides(36 cases, 4.6%); acetaminophens(34 cases, 4.4%); anticonvulsants(18 cses, 2.3%); neuroleptics(13 cases, 1.6%); hydrocarbons(9 cases, 1.2%); sympathomimetics(8 cases, 1.0%). 2. The leading causes of seizures were antihistamines(12 cases, 42.8%); insecticides(7 cases, 25.0%); sympathomimetics(3cases, 10.7%); neuroleptics(2 cases, 7.2%); others(4 cases, 14.3%). 3. Seizures associated with antihistamines were generally brief(11 cases, 92.0%) and uncomplicated(3 cases, 25.0%). 4. Seizures incidence by drug intoxication was relatively high in sympathomimetics(3 cases, 35.7%); and neuroleptics(2 cases, 15.4%). 5. Poisoning associated with seizure had relatively high risk compared with non seizure poisoning for medical complication.
Drug Overdose* ; Histamine Antagonists ; Incidence ; Poisoning* ; Seizures*

Chlopheniramine (chlorphenamine) is a racemic antiallergic antihistaminic H1 drug presenting 2 enantioners. The bioequivalence of two sustained-released formulations of racemic chlopheniramine combined with phenylpropanolamine was assessed firstly, in a dissolution test in vitro according to USP requirements. The present work compares in vitro dissolution rates of two formulations of chlopheniramine maleate. The two formulations are equivalent in vitro, both in a water medium or in a SGF/SIF medium. The pH is not a critical parameter affecting drug release and allows to use purified water for chlopheniramine dissolution test
Chlorpheniramine ; Pharmaceutical Preparations ; Histamine H1 Antagonists

Allergic conjunctivitis is characterized by specific immunologic responses known as type 1 hypersensitivity, resulting in corneal and conjunctival inflammation. Histamine plays an important role in the pathophysiologic mechanism of allergic conjunctivitis. Five subtypes of allergic conjunctivitis have been defined according to specific signs and symptoms: seasonal allergic conjunctivitis, perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis and giant papillary conjunctivitis. Above all, avoidance of the offending antigen is the primary behavioral modification used to treat all types of allergic conjunctivitis. However, this may be difficult for practical reasons; therefore, a range of medical treatment options, such as topical antihistamines, mast cell stabilizers, non-steroidal anti-inflammatory drugs, and corticosteroids are prescribed in clinical practice.
Adrenal Cortex Hormones ; Conjunctivitis, Allergic* ; Histamine ; Histamine Antagonists ; Hypersensitivity ; Inflammation ; Keratoconjunctivitis ; Mast Cells ; Seasons

Many of the patients visit the doctors because of itching sensation. Itching is an unpleasant sensation. In the epidermal keratinocytes, various neurotransmitters and receptors are related itching. The itch signal is mainly transmitted through the lateral spinal ganglion-derived nerve fibers extending to the lower epidermis. Many mediators such as histamine are involved in the itching pathway. It can be helpful in the treatment of patients having itching sensation with a lot of new therapies from the basic medication such as antihistamines. Also, many drugs are currently under study.
Epidermis ; Histamine ; Histamine Antagonists ; Humans ; Keratinocytes ; Nerve Fibers ; Neurotransmitter Agents ; Pruritus ; Sensation

Since Ernst Fuchs had described the chronic cyclitis as cyclitis in 1892, there have been many reports about the chronic cyclitis with the development of the binocular indirect ophthalmoscope and the Schepens' scleral depressor and gonioscope. The chronic cyclitis comes incidious onset with minimal symptoms of hazy vision and vitreous opacity. The authors experienced a case of chronic cyclitis of the left eye of 33 year old male patient who has been treated with systemic corticosteroid and antihistamines. Here, we briefly report it referring the literature about the chronic cyclitis.
Adult ; Histamine Antagonists ; Humans ; Male ; Ophthalmoscopes ; Telescopes ; Uveitis, Intermediate*

Torsade de Points is unique polymorphic ventricular tachycardia associated with QT interval prolongation. The mechanism of Torsade de Points was not defined exactly but triggered activity associated with afterdepolarization and/or dispersion of repolarization were known possible explanation. Torsade de points is most often induced by various drugs such as antiarrythmic agents, antipsychotic agents, antibiotis, and antihistamines. Astemizole(Hismanal(R)) and Terfenadine among antihistamines are reported that cause leading to a Torsade de Points. We experienced the case of Torsade de Points which was induced with Piprinhydrinate(Diphenylpyraline, Plokon(R)), antihistamine of ethanolamine derivatives, expressed recurrent syncope and dizziness in a young lady.
Antipsychotic Agents ; Dizziness ; Ethanolamine ; Histamine Antagonists ; Syncope ; Tachycardia, Ventricular* ; Terfenadine

There seem to be several pitfalls in an anatomic, diagnostic protocol for the evaluation of chronic cough. Instead, it is reasonable to propose that non-asthmatic chronic cough depends on the combined effects of an underlying, abnormally enhanced cough reflex and aggravating factors. Unexplained chronic cough is distressingly common despite a systematic diagnostic approach. It is often related to bronchial hypersensitivity and nonspecific bronchial inflammation. Inhaled corticosteroid (ICS) is effective for asthmatic cough. ICS is less effective in non-asthmatic cough than in asthma but not ineffective. It can be modestly effective in a significant portion of patients with non-asthmatic cough. Cough itself can induce upper airway mucosal inflammation, which could enhance the cough reflex and viciously aggravate cough. Therefore, an antitussive agent is not a just symptom controller but can play a major role in successful cough control. Cough can be more effectively controlled by behavioral interventions, with psychological counseling in addition to a pharmacological approach. ICS and antihistamines can reduce cough regardless of its cause, so therapeutic diagnosis is a misconception in the diagnosis of cough.
Asthma ; Cough* ; Counseling ; Diagnosis ; Histamine Antagonists ; Humans ; Hypersensitivity ; Inflammation ; Reflex