Clozapine and gastro-oesophageal reflux disease (GORD) - an investigation of temporal association.

OBJECTIVE: To establish the temporal relationship between prescription of acid-suppressant therapy, GORD and clozapine prescribing. METHOD: In this retrospective cohort study, we identified out-patients prescribed clozapine and other atypical antipsychotics (AAP) and compared times and rates of prescribing of acid-suppressant therapy. Odds ratios were calculated. RESULTS: Of 352 patients on clozapine and 358 patients on other AAP, there were 74 (21.0%) and 23 (6.7%) patients prescribed acid-suppressant therapy respectively [OR = 3.9 (95% CI: 2.4-6.4) P ≤ 0.0001]. In 67 of 74 cases (90.5%) vs. 18 of 23 cases (81.8%), acid-suppressant therapy began after the start of the antipsychotic. Clozapine patients were more likely to be prescribed acid-suppressant therapy within the first 5 years of initiation than those on other AAP (P = 0.039). Where indication for acid-suppressant therapy was known, it was prescribed for GORD in 44 of 62 (71.0%) of the clozapine patients and 6 of 13 (46.2%) of those on other AAP (P = 0.109). Rate of known GORD was 44 of 352 (12.5%) for clozapine and 6 of 358 (1.7%) for other atypicals [OR = 8.4 (95% CI: 3.5-19.9) P ≤ 0.0001]. CONCLUSION: Clozapine was associated with higher rates of GORD and acid-suppressant therapy prescribing than other AAP. There was a clear temporal relationship between the prescribing of clozapine and the later use of acid-suppressant therapy. These observations strongly suggest that prescription of clozapine was associated with the onset of GORD.

Invited article: CO2 laser production of fused silica fibers for use in interferometric gravitational wave detector mirror suspensions.

In 2000 the first mirror suspensions to use a quasi-monolithic final stage were installed at the GEO600 detector site outside Hannover, pioneering the use of fused silica suspension fibers in long baseline interferometric detectors to reduce suspension thermal noise. Since that time, development of the production methods of fused silica fibers has continued. We present here a review of a novel CO(2) laser-based fiber pulling machine developed for the production of fused silica suspensions for the next generation of interferometric gravitational wave detectors and for use in experiments requiring low thermal noise suspensions. We discuss tolerances, strengths, and thermal noise performance requirements for the next generation of gravitational wave detectors. Measurements made on fibers produced using this machine show a 0.8% variation in vertical stiffness and 0.05% tolerance on length, with average strengths exceeding 4 GPa, and mechanical dissipation which meets the requirements for Advanced LIGO thermal noise performance.