title: Determinants of headache in lansoprazole users in The Netherlands: results from a nested case-control study.
abstract: OBJECTIVE
  During proton pump inhibitor (PPI) use, in clinical trials, headache is one of the most frequently reported adverse events (frequency 1.3 to 8.8%), while results of one observational study indicate that headache is the fifth most frequently reported adverse event (incidence densities 2.5 to 4.6 per 1000 patient-months of exposure). However, there are no observational studies performed regarding the occurrence and features of headache during use of PPIs in daily practice. For this reason this study was set up with the aim to assess the incidence and characteristics of headache and to investigate possible associated co-factors in PPI users in daily practice.
  
  
  METHODS
  Data were used from a prospective, observational study in which 10 008 lansoprazole users were followed over time. The study was designed according to the Safety Assessment of Marketed Medicines guidelines. A nested case-control design was used to compare PPI users reporting headache or not.
  
  
  RESULTS
  The frequency of headache was 2.5% in users of lansoprazole and the incidence density was 7.2 per 1000 patient-months of PPI lansoprazole use. Two-thirds of patients with headache had tension headache and one-third had migraine. The analysis of co-factors revealed that women, patients with previous use of analgesics and patients reporting several adverse events, were at risk to develop headache during PPI use. Patients with headache also, significantly more often, reported diarrhoea, nausea and dizziness. A discontinuation of PPI therapy resulted in a cessation or reduction of the headache in 80.0% (20 of 25).
  
  
  CONCLUSIONS
  As can be expected, headache was reported less frequently in this study compared with clinical trials with lansoprazole. The incidence density was comparable with other observational data of lansoprazole and omeprazole users. Besides several commonly accepted co-factors such as female gender and a history of analgesic use, we also found the reporting of other adverse events to be associated with the reporting of headache during lansoprazole use. The cessation of headache after a discontinuation of use of the PPI and the observed dose relationship suggested that headache was indeed an adverse effect of lansoprazole use.
authors: Department of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht, The Netherlands. claessens.angela@kendle.com
authors: Angela A M C
authors: AA
authors: Claessens
authors: Eibert R
authors: ER
authors: Heerdink
authors: Jacques T H M
authors: JT
authors: van Eijk
authors: Cornelis B H W
authors: CB
authors: Lamers
authors: Hubert G M
authors: HG
authors: Leufkens
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000009:adverse effects; D006261:Headache / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D064747:Lansoprazole; D016555:Matched-Pair Analysis; D008875:Middle Aged; D009426:Netherlands; D009853:Omeprazole / Q000009:adverse effects* / Q000031:analogs & derivatives*; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D004791:Enzyme Inhibitors; D064747:Lansoprazole; D009853:Omeprazole