Evidence for an effect of sodium cromoglycate on sensory nerves in man.

Sodium cromoglycate was given by both intravenous injection and local intra-arterial infusion to healthy volunteers. Intravenous injection of a dose of 4 mg in four subjects caused a statistically significant rise in blood pressure and pulse rate associated with a feeling of warmth in the perineum and blush areas of the face and chest. Brachial artery infusion of sodium cromoglycate at doses of 100-1000 microgram/min caused a feeling of warmth in the limb during 26 out of 30 infusions and this sensation was subject to tachyphylaxis. During eight infusions in which there was a sensation of warmth there was no change in local blood flow as measured by strain-gauge plethysmography. In a further six studies involving 12 infusions of sodium cromoglycate the feeling of warmth was not accompanied by a rise in local skin temperature. The results suggest that sodium cromoglycate may stimulate afferent nerves in man.