[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.
Castanedo-Cazares
Juan Pablo
JP
Departamento de Dermatología, Hospital Central Dr. Ignacio Morones Prieto, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí SLP, México.
Torres-Alvarez
Bertha
B
Martínez-Rodríguez
Alejandra
A
Díaz-Rosales
Adriana
A
Moncada
Benjamín
B
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