The CSO said that €3.9 billion worth of goods were exported to the US in November - down 51% year on year.
But between January and November exports to the US were up 60% year on year to €108.4 billion, reflecting the front-loading many exporters engaged in to get ahead of US tariffs.
Today's figures show that overall Irish exports fell 17% to €3.5 billion in November, but were up 18% in the first 11 months of the year to 37.4 billion.
Meanwhile imports of goods rose slightly by 1.8% to €215m to €12 billion in November.
Ireland's main exporting partners were the US, the Netherlands and Belgium in November, with Ireland exporting 22.9% (€3.9 billion), 12.1% (€2.1 billion) and 11.9% (€2 billion) of total exports respectively to these countries.
Ireland imported the highest value of goods in November from the US, Great Britain and China with these countries representing 14.2% (€1.7 billion), 11.8% (€1.4 billion) and 10.9% (€1.3 billion) of the total import trade respectively.
Meanwhile, exports to Great Britain eased by €9.5m (-0.7%) to €1.28 billion in November compared to the same time last year, while imports from Great Britain increased by €56.5m (4.2%) to €1.41 billion.
On the surface this looked dramatic, with US-bound pharma shipments falling far below their levels a year earlier. However, these monthly swings need to be seen in the context of the overall year. Over the first part of the year, pharmaceutical exports to the US surged compared with the previous year, while overall exports were also significantly higher. This suggests that much of the apparent weakness reflects timing rather than a deterioration in demand. Exports recovered modestly in November, although they remained below last year's level. The year-on-year decline was again concentrated in medical and pharmaceutical products, while other sectors such as organic chemicals and technology-related exports showed growth.
For investors and policymakers alike, hopefully the real story is not falling demand but uneven shipment timing in the pharma sector.