Antihistamines promethazine

An aqueous solution of the antihistamine, promethazine (361) hydrochloride, was photolysed to promethazine sulphoxide, phenothiazine, phenothiazine sulphoxide and 3//-phenothiazin-3-one (362) [206]. 

Phenergan contains the antihistamine promethazine. Valium contains the benzodiazepine diazepam. Both the antihistamine and the benzodiazepine tend to reduce the blink rate, leading to dry eyes. Cilest is a combined oral contraceptive, which, like other oral contraceptives, may cause reduced tolerance because of corneal and eyelid oedema. 

The conventional (or classical) neuroleptics comprise two classes of compounds with distinctive chemical structures 1. the phenothiazines derived from the antihistamine promethazine (prototype chlorpromazine), including Ltillmann, Color Atlas of Pharmacology 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 

There are also known cases of drug enantiomers that possess completely different therapeutic properties. The (+)-2/ ,35 -stereoisomer of propoxyphene (dextropropoxyphene) is marketed as an analgesic agent, whereas its enantiomer ( )-(25, 3/ )-propoxyphene (levopropoxyphene) is available as an effective anti-tussive agent [3]. The enantiomers of some chiral drugs are known to possess essentially identical qualitative and quantitative pharmacological activities, for example, the antihistamine promethazine, which is marketed as a racemate [5]. 

Chlorpromazine Prochlorperazine Fluphenazine Butyrophenones Droperidol Domperidone Antihistamines Promethazine Diphenhydramine Benzamides Metoclopramide Serotonin antagonists Ondansetron Granisetron Tropisetron... 

A number of other medications may be used pre-operatively to achieve various goals (see Table 11-2).5,40 Antihistamines (promethazine, hydroxyzine)... 

Another example is the discovery made during the use of the antihistamine promethazine to treat surgical shock. In order to improve potency, a chlorine atom was incorporated into the drug molecule. Subsequently, when the patients seemed to be unconcerned about undergoing surgery, chlorpromazine - the first... 

OPIOIDS ANTIHISTAMINES Promethazine t analgesic and anaesthetic effects of opioids. However, it has an additive sedative effect Unknown Monitor vital signs closely during coadministration... 

Tricyclic Antidepressants. Irnipramine [50 9-7] (32), which was the first tricydic antidepressant to be developed, is one of many usefiil psychoactive compounds derived from systematic molecular modifications of the antihistamine promethazine [60-87-7] (see HiSTAMINE AND HISTAMINE antagonists). The sulfur atom of promethazine was replaced with an ethjiene bridge and the dimethyl amino group attached to an -propyl group, rather than to an isopropji one, of the side chain. The actual synthesis of (32) is typical of the compounds in this class (37). 

Phenothiazines were developed after it was noticed that the antihistamine, promethazine had a sedative action. 

Like other antihistamines, promethazine has signih-cant anticholinergic effects it should be used with caution in patients with narrow-angle glaucoma, peptic ulcer, or pyloroduodenal obstruction or urinary bladder obstruction from prostatic hypertrophy or narrowing of the bladder neck. It also should be used with caution in patients with CVD or hypertension because of the risk of palpitations with acute or chronic respiratory dysfunction (especially children) as promazine may depress the cough reflex. 

N-substituted phenothiazines with basic side chains (e.g. the antihistamine promethazine, and the tranquillizer chlorpromazine) are accumulated in the eyes of all mammals. A concentration 50 times as great as in other tissues is often reached (Potts, 1962). 

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