The impact of opiate pain medications and psychoactive drugs on the quality of colon preparation in outpatient colonoscopy

Background: Suboptimal colon preparation is a significant barrier to quality colonoscopy. The impact of pharmacologic agents associated with gastrointestinal dysmotility on quality of colon preparation has not been well characterized. Aims: Evaluate impact of opiate pain medication and psychoactive medications on colon preparation quality in outpatients undergoing colonoscopy. Methods: Outpatients undergoing colonoscopy at a single medical centre during a 6-month period were retrospectively identified. Demographics, clinical characteristics and pharmacy records were extracted from electronic medical records. Colon preparation adequacy was evaluated using a validated composite colon preparation score. Results: 2600 patients (57.3. ±. 12.9 years, 57% female) met the inclusion and exclusion criteria. 223 (8.6%) patients were regularly using opioids, 92 antipsychotics, 83 tricyclic antidepressants and 421 non-tricyclic antidepressants. Opioid use was associated with inadequate colon preparation both with low dose (OR=1.4, 95%CI 1.0-2.1, p=0.05) and high dose opioid users (OR=1.7, 95%CI 1.1-2.9, p=0.039) in a dose dependent manner. Other significant predictors of inadequate colon preparation included use of tricyclics (OR=1.9, 95%CI 1.1-3.0, p=0.012), non-tricyclic antidepressants (OR=1.5, 95%CI 1.1-2.0, p=0.013), and antipsychotic medications (OR=2.2, 95%CI 1.4-3.4, p=0.001). Conclusions: Opiate pain medication use independently predicts inadequate quality colon preparation in a dose dependent fashion; furthermore psychoactive medications have even more prominent effects and further potentiates the negative impact of opiates with concurrent use.