Domperidone

Day 1: After recognition that early antipsychotic drugs acting on dopamine pathways had an impact on vomiting, the search was on for an anti-emetic without extra pyramidal side-effects (EPS). #domperidone was licensed in the 1970s

Day 2: Indications for #domperidone; relief of nausea/vomiting for those over 12 years & over 35kg. Dose 10mg up to three times/day for 1 week, including 2nd line for nausea/vomiting in pregnancy. Same dose used for GI pain in adult palliative care

Day 3: #domperidone has rapid oral absorption with high first pass metabolism in the gut & liver. High Vd (low concn in brain), hepatic phase 1 breakdown e.g CYP3A4 & 1A2. 2/3 faecal excretion with small amount unchanged. T½ 7-9hrs; prolonged if severe renal or hepatic impairment

Day 4: #domperidone has a dual anti-emetic effect via blocking dopamine receptors in the chemoreceptor trigger zone & accelerating gastric motility & emptying (pro-kinetic effect)

Day 5: Common ADEs: dry mouth. Uncommon: reduced libido, anxiety, headache, diarrhoea, breast pain. Unknown: anaphylactic reaction, convulsion, urinary retention, ventricular arrhythmia, sudden cardiac death, QT prolongation, Torsade de Pointes (NOT exhaustive)