Drug-induced pancreatitis (DIP) is considered a relative rare disease entity, possibly due to lack of recognition. Its diagnosis is often challenging because of the lack of unique clinical features to distinguish it from acute pancreatitis (AP) due to other causes. The latest adapted classification system for DIP was published in 2007 and categorised 120 drugs into four classes based on the published weight of evidence with AP:

• Class I includes drugs of which at least one case report with recurrence of AP after rechallenge has been published.
• Class II includes drugs in which there is a consistent latency in 75% or more of the reported cases.
• Class III includes drugs that have neither a rechallenge nor a consistent latency period, but at least two cases are reported.
• Class IV drugs are similar to class III, but only one case report is reported

This paper reports a Dutch observational study evaluating the aetiology, disease course, use, and discontinuation of pancreatitis-associated drugs at hospital admittance and discharge in a cohort of patients with an established clinical diagnosis of AP or recurrent AP, according to the latest evidence-based DIP classification system.

The first documented hospital admissions of 168 patients were analysed and the following findings reported:

• 70 out of 168 (41.6%) patients used pancreatitis-associated drugs at admission.

• In 26.2% (44/168) of cases, at least one class I pancreatitis-associated drug was used.

• Most often, the class I drug was a cardiovascular or gastrointestinal agent.

• The most frequently used class I drugs, single or in combination with other drugs, were simvastatin (class Ia) 29.5% (13/44), enalapril (class Ia) 22.7% (10/44), and omeprazole (class Ib) 20.5% (9/44).

• DIP was possibly present in 12.5% (21/168); in less than half of these patients (9/21 or 42.9%), the prescribed drugs were actually discontinued, with no recurrence of AP later on.

• Among the remaining 12 patients without discontinuation of their drugs use and in absence of an alternative aetiological cause of AP, 8 used a class I pancreatitis-associated drug, representing 4.8% (8/168) of the total study population.

The researchers conclude that “in this series, a remarkably high percentage of patients who were admitted because of an attack of AP used pancreatitis-associated drugs. Physicians should be more aware of the possibility of DIP in patients with otherwise unexplained AP and act appropriately by discontinuation of the drug.”