Antipruritic Drugs Research Articles

Studies on Charge-Transfer and Hydrogen Bond Formation with Cyproheptadine

Cyproheptadine, an antihistaminic and antipruritic drug, forms fairly stable charge-transfer complexes with quinone (Q), chloranil (Chl-Q) and anthraquinone (AQ) in chloroform. It also forms stable hydrogen bonds with alcohols (methanol and propanol) and phenols (α-naphthol,The results suggest that cyproheptadine can form loose association with receptors through charge-transfer and hydrogen bond complex formation.

Inhibitory effect of Byakko-ka-ninjin-to on itch in a mouse model of atopic dermatitis.

Byakko-ka-ninjin-to (BN) is composed of gypsum, the root of anemarrhena, ginseng, licorice and rice. The effect of BN on the inhibition of itch was studied using an NC mouse model of atopic dermatitis. BN (200 mg/kg, p.o.) significantly inhibited the scratching frequency in NC mice, and decreased the skin temperature by 1.97 degrees C. The cooling action on the skin by BN may be involved in the inhibitory mechanism of itch, at least in part, since cooling the skin is known to inhibit the itch sensation in humans. Although the myocyte-specific enhancer binding factor 2C (MEF2C) mRNA is known to be increased in the cerebral cortex correlated with the itch sensation and skin lesions in NC mice, BN did not affect the expression level of the MEF2C mRNA. This result suggests that the inhibitory effect of BN on itch does not relate to inhibition of MEF2C expression in the cerebral cortex. The present study indicates that BN has an inhibitory effect on itch, and may be a useful antipruritic drug for atopic dermatitis.

Inhibitory effects of methanol extracts of herbal medicines on substance P-induced itch-scratch response.

In a search for new anti-pruritic drugs we screened methanol extracts of 33 herbal medicines which have been used for cutaneous diseases for their antipruritic activity using substance P (SP) as a pruritogen in mice. When administered perorally 30 min before SP injection, methanol extracts of 6 of these herbal medicines, the root of Scrophularia ningpoensis Hemsl., the root of Patrinia villosa (Thunb.) Juss, the fruit of Forsythia suspenna Vahl, the rhizome of Cimicifuga dahurica (Turcz.) Maxim., the aerial part of Schizonepeta tenuifolia Briq. and the fruit of Cnidium monnieri (L.) Cuss, inhibited SP-induced itch-scratch response at a dose of 200 mg/kg with-out affecting locomotor activity. Dose dependence of these 6 extracts (50-500 mg/kg) was investigated and all of them inhibited SP-induced itch-scratch response, with extracts from Scrophularia ningpoensis, Schizonepeta tenuifolia and Cnidium monnieri showing particularly significant inhibition. The results suggest that these 6 methanol extracts have inhibitory activity against SP-induced itching.

Effect of topical pramoxine on experimentally induced pruritus in humans

Itch, pain, and thermal sensations share a common peripheral neural pathway; each is transmitted by small nerve fibers, especially the C fibers. 1 In contrast to pain that can be effectively treated with analgesics, there is no universally effective antipruritic drug. Evaluation of antipruritics is difficult because of the lack of objective criteria. Few placebo-controlled efficacy trials have been conducted.

Antipruritic drug therapy in the dog and cat

In PracticeVolume 16, Issue 3 p. 137-147 Companion Animal PracticeFree to Read Antipruritic drug therapy in the dog and cat Gordon Sture, Gordon StureSearch for more papers by this author Gordon Sture, Gordon StureSearch for more papers by this author First published: 01 May 1994 https://doi.org/10.1136/inpract.16.3.137AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume16, Issue3May 1994Pages 137-147 RelatedInformation

Late phase reactions.

Our current understanding of LPR has evolved over the past 10-12 years, and there are still many areas where our information is still incomplete and cannot provide solid support for several of the hypotheses presented herein. Each suggestion presented is testable, however, and answers to many of the questions raised should eventually be available. The hypotheses presented provide a framework for understanding how airway inflammation contributes to airway reactivity and how certain irritant exposures can cause delayed-onset asthma. More importantly, they provide a rationale for the use of many of the specific drugs used to treat allergies and asthma. Indeed, if LPR and airway inflammation are as important in asthma (and other allergic diseases) as these hypotheses suggest, the use of agents specifically designed to prevent or treat LPR should increase. Thus, mast cell stabilizing compounds such as cromoglycate, ketotifen, and tranilast and anti-inflammatory agents like GCS might be viewed as specific therapy for asthma (and other allergic diseases), while bronchodilators (like antihistamines, decongestants and antipruritic drugs in other allergic diseases) might be considered as supportive agents. These concepts therefore suggest the early and aggressive use of specific agents in asthma while employing supportive drugs to help maintain lung function.

PUVA, Pruritus, and the Loss of the Axon Flare

<h3>To the Editor.—</h3> Severe pruritus, especially over the buttocks, was seen in two middle-aged men who were approaching a maintenance-schedule program (7 joules/sq cm) of psoralens and ultraviolet-A light (PUVA). Both men failed to exhibit the axon-flare response with the intradermal injection of 0.1 mL of histamine phosphate (0.1 mg/mL) into the buttock. Both men demonstrated the axon-flare response in less symptomatic areas. A neurology consultant, unaware of the histamine skin test, examined the first man and diagnosed a peripheral neuropathy of mainly unmyelinated fibers that affected the hands, feet, nose, and buttocks. There was hyperesthesia of the buttock. The PUVA program was stopped, and the flare had returned when the patient was tested three months later. The histamine intradermal test should prove useful in evaluating pruritus associated with PUVA. Loss of axon-flare reflex vasodilation should end any dilemma about treating the patient with antipruritic drugs during this period.

Evaluation of antipruritic drugs in normal volunteers.

The antipruritic effect of trimeprazine and ergotamine was evaluated in medical students by use of the double‐blind technique. Itch was induced by Mucuna pmriens (cowage) ointment. Ergotamine tartrate was found to be ineffective, whereas no definite opinion could be formed regarding trimeprazine tartrate.

Controlled trials of two oral antipruritic drugs, trimeprazine and methdilazine.

Controlled trials of two oral antipruritic drugs, trimeprazine and methdilazine.

Clinical Evaluation of Antipruritic Drugs

Recently, an attempt was made to evaluate the antipruritic effect of an analgesic drug. Some of the problems encountered will be discussed, and a blueprint for the proper clinical investigation of antipruritic drugs will be presented. Experimental Procedure In previous animal experiments, the drug was found to depress the perception of cutaneous stimuli. In addition, it was found to have potent local anesthetic activity, mild antihistaminic action, and potentiation of analgesia. The case material consisted of patients with severe chronic pruritus. In a pilot study on 23 patients, the drug showed considerable promise, and a subsequently administered placebo was ineffective. The experiment was then continued with 79 additional cases, with use of a carefully planned, double-blind, randomized technique. Statistical analysis of the complete data demonstrated that the test drug was not superior to the placebo. Appreciation of the difficulties and pitfalls inherent in the study led to a

Clinical study of quotane, a new antipruritic drug.

PROBABLY all physicians would welcome the development of a safe antipruritic drug, for it is generally recognized that such drugs are highly sensitizing to normal or inflamed skin, often doing more harm than good. As to the effectiveness of these drugs, opinion is divided, with too few critical surveys such as those of Shelley and Melton, 1 who concluded their studies with a pessimistic view. A new group of compounds (amino-alkoxy isoquinolines) has recently been found to possess anesthetic properties. 2 Preliminary studies on animals showed one of these drugs, SKF 538-A, or 1-(β-dimethylaminoethoxy)-3-n-butylisoquinoline monohydrochloride, to be relatively nontoxic and to possess (by the rabbit cornea technic) anesthetic properties 10 times those of dibucaine hydrochloride, the most effective of the other preparations compared in the studies. 3 When preliminary clinical tests revealed no tendency of the compound to irritate or sensitize intact or abraded