Do Systemic Antipruritic Agents Work?

Abstract

‘Most of the agents recommended for the control of itching during the last two decades have not stood the test of time. Many have been discarded, and the continuing use of several of the remaining ones has been dictated not so much by the results obtained as by the desire to prescribe something for the complaining patient.’ Another 20 years have slipped past since Cormia & Dougherty wrote so bluntly about the subject in 1959. But has the picture really changed? The complaining patients still exist and skin clinics still echo to the rasp of fingernails on skin. There is obviously still a demand for at least one effective antipruritic agent, to be used in conditions like atopic eczema which cannot always be controlled by topical measures, and which cause long‐term distress. This demand is matched by a mass swallowing of drugs reputed to have antipruritic effects—at least 50,000 prescriptions being issued each year in the United Kingdom alone. Yet despite this, skin text books are still coy about confirming that these drugs, usually antihistamines, do in fact suppress itching. Patients are sometimes less complimentary. This review attempts the difficult task of assessing whether, 20 years on, the use of so‐called antipruritic agents is still based upon inadequate evidence.

Involvement of histamine H4 and H1 receptors in scratching induced by histamine receptor agonists in BalbC mice

“…Although traditional H 1 receptor antagonists are effective at reducing histamine‐induced itch ( Hagermark et al ., 1979 ) and are widely used clinically for treating pruritus ( Greaves, 1997 ), they are not effective antipruritics in many clinical conditions, such as atopic eczema ( Yosipovitch et al ., 2003 ). It has been claimed that the effectiveness of H 1 receptor antagonists in relieving itch results from central sedation rather than peripheral actions on sensory nerves, in conditions where histamine is not considered to be the primary mediator ( Savin, 1980 ; Krause & Shuster, 1983 ; Savin et al ., 1986 ). Histamine H 2 receptor antagonists are also used clinically for treating itch ( Monroe et al ., 1981 ; Ring et al ., 1999 ), but their ability to inhibit itching is not conclusive ( Hagermark et al ., 1979 ; Davies & Greaves, 1980 ).…”

Poster Communications

“…Ketoprofen C2(3-benzoylphenyl)propionic acid], a non-steroidal antiinflammatory agent, is widely used for the treatment of arthritic symptoms, and when administered in the form of 'Orudis' or 'Profenid' has a short plasma elimination half-life of around 2 h (e.g. Caille , 1980Sala et al, 1978;Ishizaki et al, 1980;Stafanger et al, 1981). In order to permit once daily dosing of ketoprofen and reduce the possibility of gastro-intestinal side-effects a controlled release preparation known as 'Oruvail' is now available.…”

Failure of Mexiletine to Relieve Severe Pruritus

“…There are as yet no systemic drugs avail able with specific antipruritic effects [1], Though antihistamines may be useful in conditions where histamine is involved, e.g., urticaria, their beneficial effects in other pruritic conditions may largely be due to their sedative action [2], Among the great number of therapies claimed to control pru ritus, intravenous injections of the local anesthetic lidocaine have been reported to give temporary relief of severe itch in 1 pa tient with biliary cirrhosis [3] and in 20 pa tients with uremia [4], However, regular in travenous injections of lidocaine to prevent itching can only be given to a few selected cases.…”