title: [Considerations about administration angle of prostaglandin analogs].
abstract: OBJECTIVE
  To investigate if there is any difference in volume and drop weight of prostaglandin analogs when adopting drip angles of 45 masculine and 90 masculine, regarding a horizontal line.
  
  
  METHODS
  An experimental study was conducted using the follow ophthalmic solutions: latanoprost, travoprost and bimatoprost. In this study the ophthalmic solutions were dripped according to an angle of 45 masculine or 90 masculine. Prostaglandin analogs were chosen due to their common use in ophthalmology and their cost. The first drop and other ten drops were weighed, alternating the drip angle (45 masculine or 90 masculine). Statistical analysis was done with SPSS 12.0 (Microsoft), using quantitative comparisons with the ANOVA test. An odds value (P) below 0.001 was considered a statistical significant difference.
  
  
  RESULTS
  We verified differences in weight and size of the travoprost and bimatoprost drops instilled at 45 masculine and 90 masculine. The drip at 45 masculine produces a smaller drop of travoprost (P<0.001), and the inverse occurs for bimatoprost. There were no statistical significant differences in weight of latanoprost drops according to the instillation angle.
  
  
  CONCLUSIONS
  Once there was statistical difference in weight--which has direct relationship with size--of the drops of two kinds of prostaglandin analogs and in another one we did not observe this variation, we infer that cost and therapy duration estimates should be analyzed carefully, especially if this kind of drip measure is used.
authors.affiliation: Faculdade de Medicina, Universidade de Passo Fundo, Passo Fundo, RS, Brasil. paulo@estacia.trix.net
authors.forename: Paulo
authors.initials: P
authors.lastname: Estacia
authors.forename: Taíse
authors.initials: T
authors.lastname: Tognon
mesh_terms: D000577:Amides / Q000008:administration & dosage; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000191:economics; D000069580:Bimatoprost; D003008:Cloprostenol / Q000008:administration & dosage / Q000031:analogs & derivatives; D005901:Glaucoma / Q000188:drug therapy; D006801:Humans; D007322:Instillation, Drug; D000077338:Latanoprost; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000191:economics; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage* / Q000191:economics; D000069557:Travoprost
chemical_list: D000577:Amides; D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions; D011461:Prostaglandins F, Synthetic; D003008:Cloprostenol; D000077338:Latanoprost; D000069580:Bimatoprost; D000069557:Travoprost