When midazolam fails.

Significant distress is experienced by patients, families, and caregivers when a symptom or disorder, such as an agitated delirium, becomes an intractable, or a catastrophic event, such as irreversible stridor. When palliative sedation is indicated for these patients, midazolam is usually the preferred drug. In some cases, however, midazolam fails to provide adequate sedation. Two cases are presented to illustrate this phenomenon and explore the possible mechanisms underlying this lack of response. These mechanisms appear to be multifaceted. The heterogeneity of the GABA(A) receptor complex and the alterations that this complex can undergo functionally can explain, to some degree, the diversity of the physiological and pharmacological outcomes. Other factors responsible for the diversity in response may include concomitant medications, age, concurrent disease, overall health status, alcohol use, liver disease, renal disease, smoking and hormonal status. Evidence-based guidelines on alternative treatment options should midazolam fail are required. In the interim, a lower threshold for adding an alternative drug, such as phenobarbital, or substituting midazolam with another drug, such as propofol, should be considered in these circumstances.