Counter irritant effect

Tretinoin, (vitamin A acid, retinoic acid,) is a counter-irritant effective in some types of acne it is also used in psoriasis, with doubtful efficiency. Contact allergy to locally applied retinoic acid has been reported (Lindgren et al. 1976). Patch testing with the commercial preparations containing 0.05% vitamin A acid and with vitamin A acid 0.05% in alcohol is recommended. 

This mediated activation of the immune system might be explained also by the so-called counter irritant effect [43]. 

In this context, the role of adhesion molecules and complement receptors found on macrophages, neutrophils and NK-cells and the role of leukocyte chemotaxis might be of importance and should therefore be investigated. Furthermore, the influence of polysaccharides on endocrine functions (counter irritant effect), on prostaglandin metabolism, or on the NO-mediators have to be taken into consideration. 

Since Rocha e Silva et al. [76] have reported that a number of sulphated polymers show antiinflammatory potential, counter irritation has been discussed as one possible mechanism. Beside turpentine [71] and sulphated polysaccharides, a neutral glucan was also found to possess irritating and inflammation-inducing activity [77]. Most likely this class of polysaccharides also exhibits antiinflammatory effects in the carrageenan rat paw edema through counter irritation. This could be of great importance in acute animal inflammation models, since Ferreira et al. [78] demonstrated that counter irritant effects were able to reduce edema formation as early as 2 h after administration of the irritating substance. 

Inhibitors of the adrenocorticoid synthesis [79] neutralize counter irritation effects suggesting participation of the symphato-adrenal system. The first evidence for the involvement of neutral glucans in the induction of adrenocorticoid release was reported by Wang and Zhu [73]. A P-glucan from Omphalia lapidescens which has shown antiinflammatory activity in animal models, was able to increase the... 

Camphor is used in acne medications, cough remedies, ear drops, and other medications where its ability to soothe the skin helps it to counter the effects of other ingredients that might otherwise be irritants. 

The most significant actions of alkamides are analgesic, antiinflammatory, counter-irritant, sialagogue, vermifuge, digestive and circulatory stimulation. Other likely effects are spasmolytic, carminative and immune stimulation. 

Ipecac is prepared from the dried roots and rhizomes of Cephaelis ipecacuanha (Brot.) A. Rich, and contains the alkaloids emetine [483-18-1] (17) and cephaeJine [483-17-0] (18) in a ratio between 2 1 and 4 1. It has been used extensively in cough preparations and is beheved to act by gastric reflex stimulation. Toxic effects include vomiting, irritation of the gastrointestinal tract, and cardiac arrhythmias (19). Ipecac symp is available over-the-counter in the United States only in 30-mL containers for use as an emetic in treating poisonings. 

Melatonin appears to be well tolerated and is often used in preference to over-the-counter "sleep-aid" drugs. Although melatonin is associated with few adverse effects, some next-day drowsiness has been reported as well as fatigue, dizziness, headache, and irritability. Melatonin may affect blood pressure as both increases and decreases in blood pressure have been observed. Careful monitoring is recommended, particularly in patients initiating melatonin therapy while taking antihypertensive medications. 

SAFETY PROFILE Poison by ingestion and intravenous routes. Moderately toxic by subcutaneous route. Experimental reproductive effects. Mutadon data reported. An allergen. Incompadble with acetanilide. When heated to decomposition it emits acrid smoke and irritating fumes. An FDA over-the-counter drug used as an antibacterial and antifungal agent. 

The effects of salmeterol 50 micrograms plus fluticasone 250 micrograms delivered via a combination inhaler and via separate inhalers have been compared in 371 asthmatic patients (18). There were equivalent improvements in peak flows and asthma sjmptoms. Candidiasis, dysphonia, and throat irritation were the commonest adverse effects attributed to treatment and occurred equally in the two groups (35%). Palpitation and tremor, which may have been related to salmeterol, occurred in 2% (for each symptom) of the combination group and in 1% and under 1% of the separate inhaler group. In both of these studies compliance was measured by dose counters on the inhalers and was equivalent in the two groups. 

---