A preliminary study of cocaine absorption from the nasal mucosa

To determine factors affecting the safe use of topical cocaine for anesthesia and vasoconstriction during rhinologic surgery.

Prospective, randomized study of the kinetics of cocaine absorption through human nasal mucosa in 12 consecutive patients without nasal mucosal disease who were having septoplasty or septorhinoplasty.

With patients under general anesthesia, cocaine was applied topically to each nasal cavity by using cottonoid pledgets. Group I received 4 mL of a 4% solution (160 mg) of cocaine for 10 min, Group II received 4 mL of a 4% solution (160 mg) of cocaine for 20 min, and Group III received 4 mL of a 10% solution (400 mg) of cocaine for 20 min. Absorption rate was determined by measuring serum cocaine concentration at intervals of 5, 10, 15, and 20 min. Residual cocaine was extracted from the pledgets and was analyzed quantitatively by using gas chromatography and mass spectroscopy.

Of total cocaine applied, 35% was absorbed systemically: 17% was absorbed within 5 min, 25% within 10 min, and 32% within 15 min. Of the cocaine absorbed, 47% was absorbed within the first 5 min, 70% within 10 min, and 90% within 15 min. Two patients (16.6%), both in Group III, had intraoperative hypertension; one of these patients also had transient ventricular tachycardia.

Although a 4% solution of cocaine applied to the nasal mucosa on cottonoid pledgets for 20 min is safe, we observed an idiosyncratic absorption rate four times greater than expected; therefore, we advise against topical use of a 10% cocaine solution for anesthesia and vasoconstriction during rhinologic surgery.