(P-389) Utilisation and Safety of Glycopyrronium Bromide (GPB) Oral Solution for the Treatment of Sialorrhoea in Children <18 Years in the UK

Background: Glycopyrronium bromide (GPB) is used to treat sialorrhoea (drooling) in children ≥ 3 years with chronic neurological disorders. Maintaining the positive benefit-risk profile of GPB requires careful titration as many side effects are related to the anticholinergic mechanism of action. This utilisation and safety study aimed to investigate GPB use in children, and adverse events reported during GPB treatment.

Objectives: Primary objectives were to examine utilisation of GPB oral tablets and solutions among children (aged <18 years) and in those diagnosed with sialorrhoea, as well as safety of the GPB 1mg/5ml solution prescribed for sialorrhoea in children. Secondary objectives were to characterise patients (pts) to assess potential indications for prescribing.

Methods: A retrospective cohort design was used, with two non-mutually exclusive cohorts identified from the Clinical Practice Research Datalink (CPRD) GOLD database from February 2009 to March 2020. Cohort 1 identified children who were prescribed GPB oral tablets or solutions and were GPB naïve (n=550). Cohort 2 identified children with a sialorrhoea diagnosis (n=2717).

Results: Cohort 1
53.8% had a first-ever index prescription for GPB solutions, with 68.5% of these pts prescribed the 1mg/5ml solution. Of these pts, 61.1% were between ≥ 3 and <12 years of age and 61.1% had one GPB 1mg/5ml treatment episode (TE) with a median treatment duration, in TE1, of 116.0 days (IQR 60.0-376.0). The most common prescribed total daily dose for GPB 1mg/5ml was 3mg.
7.9% had a sialorrhoea indication prior to starting GPB 1mg/5ml. The most frequently prescribed concomitant medications (5.6% of medications) were listed under the Control of Epilepsy BNF Chapter.
Cough was the most common incident event on GPB 1mg/5ml treatment (3.4% of reported events), followed by Chest infection (3.3%). Cumulative incidence (CI) risk for both Cough and Chest infection, in TE1, was 6.9% (95% CI: 3.8, 11.3) and CI rate was 7.2 per 100 person-years (95% CI: 4.3, 12.2).
Cohort 2
3.0% were GPB naïve and prescribed GPB tablets or solutions, on or after first sialorrhoea diagnosis. 50.0% of these pts were prescribed GPB solutions; with 75.6% prescribed the 1mg/5ml solution. Of these pts 61.3% were between ≥ 3 and <12 years of age and 58.1% had one GPB 1mg/5ml TE. The median treatment duration, in TE1, was 101.0 days (IQR 60.0- 433.0) and the median number of prescriptions in TE1 was 2 (IQR 1-14).

Conclusions: Frequently reported events on GPB treatment are likely to be reflective of common childhood illnesses. The safety aspect did not identify clinical events on GPB 1mg/5ml treatment which may not be expected in this population.