title: Initial uptake in use of sildenafil in general practice.
abstract: OBJECTIVE
  To assess the initial uptake in use and co-prescribing patterns of sildenafil.
  
  
  METHODS
  We examined prescription details of the Eastern Health Board Region (including Dublin) of the General Medical Services (GMS) in Ireland, which provides detail on prescriptions dispensed in primary care for this population (n = 334,031). We identified 1422 patients who received 3740 prescriptions for sildenafil over a 6-month period (July 1999-December 1999) and determined the percentage of patients who were co-prescribed nitrate therapy, medications which may interact with sildenafil and medications associated with impotence.
  
  
  RESULTS
  We identified 1422 (1.4% of the male population over 16 years who might be expected to suffer from erectile dysfunction given an overall prevalence of 10%) who received a prescription for sildenafil over the study period at a cost of 0.14% of the annual drug budget. Up to 2.5%, 6% and 25% of patients were co-prescribed, respectively, nitrate therapy, potentially interacting drugs and drugs associated with impotence.
  
  
  CONCLUSIONS
  The initial uptake and cost associated with sildenafil was lower than expected. The rate of prescribing of nitrates and other potentially interacting medications was found to be low. Medication use may also contribute to erectile dysfunction in this population of patients.
authors.affiliation: Department of Pharmacology and Therapeutics, Trinity Centre for Health Sciences, St James Hospital, Dublin 8, Ireland. williamd@tcd.ie
authors.forename: D
authors.initials: D
authors.lastname: Williams
authors.forename: J
authors.initials: J
authors.lastname: Feely
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004347:Drug Interactions; D007172:Erectile Dysfunction / Q000139:chemically induced* / Q000453:epidemiology; D005194:Family Practice; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000009:adverse effects*; D017891:Pharmacoepidemiology; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D010879:Piperazines / Q000008:administration & dosage / Q000009:adverse effects*; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D009566:Nitrates; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate