[Analysis of the digital unit as reference measurement for the topical prescription in Mexico].
BACKGROUND
Topical prescription unlike other dosage forms is generally considered an inaccurate procedure. The fingertip unit (FTU) is a proposed measure for dosing a topical drug. FTU is the amount of ointment obtained from a tube with a 5 mm diameter nozzle, applied from the distal skin-crease to the tip of the index finger.


OBJECTIVE
Asses FTU as a reference measure for topical prescription among the Mexican population.


METHODS
The length of the II hand fingertip was recorded in 324 individuals and the weight of 1 FTU and its covering surface was registered.


RESULTS
Average length of index fingertip was 24 mm (IC95 26.7-27.2) in males (n=40), and 24 mm (IC95 24.3-24.8) in females (n=50). One FTU weighed 0.45 g (IC95 0.41-0.48) in males (n=40), and 0.38 g (IC95 0.35-0.41) in females (n=50). One FTU covered 275 cm2 (IC95 255-294) in males (n=15), and 257 cm2 (IC95 200-240) in females (n=15).


CONCLUSIONS
FTU may be a helpful measure for dosing and supervising the administration of topical medications for both patients and dermatologists in Mexico.
Departamento de Dermatología, Hospital Central Dr. Ignacio Morones Prieto, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí SLP, México.
Juan Pablo
JP
Castanedo-Cazares
Bertha
B
Torres-Alvarez
Alejandra
A
Martínez-Rodríguez
Adriana
A
Díaz-Rosales
Benjamín
B
Moncada
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D011307:Drug Prescriptions / Q000592:standards*; D005260:Female; D005385:Fingers; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D010865:Pilot Projects; D012015:Reference Standards