**3.2.2.2 Opioids**

Delirium has been reported to be associated with opioid use (Gray et al., 1999, Brouquet, 2010). The association of delirium with opioids is dose-related (Burkhart et al., 2010). Persistent delirium has been reported to be associated with use of opioids at doses greater than 54mg/day (Pisani et al., 2010). On the other hand, there are studies reporting no association between opioid use and delirium (Pandharipande et al., 2006; Pisani et al., 2007). In a systemic review which aimed to determine medications to avoid in people at risk of delirium, it was concluded that, although use of opioids should be prescribed with caution in people at risk of delirium, as untreated severe pain can itself trigger delirium, this caution should be tempered (Clegg & Young, 2011).
