In general, these medications are usually given intravenously when used for procedures in the emergency department (ED), with some exceptions for children (for more information, see Pediatrics, Sedation).
Compared with other modes of administration, intravenous medications generally have a quick onset, have a predictable drug absorption, and are titratable.
Benzodiazepines differ by the methods they can be given, time of onset, action duration, mechanism of metabolism, and presence of active metabolites.
Be cautious when giving a hepatically metabolized benzodiazepine (eg, midazolam) to a patient with cirrhosis.Midazolam is metabolized by the hepatic microsomal system and is not affected by renal failure (caution with cirrhosis). Second, lorazepam does not have any active metabolites.Midazolam is the fastest acting of its class because of its lipophilic abilities, and it is superior to lorazepam and diazepam in its amnestic effects, making it the ideal benzodiazepine for use in short ED procedures. Thus, it can be given as a continuous intravenous infusion (0.03-0.1 mg/kg/h) with less concern for adverse effects than an intravenous midazolam drip.Medications with different qualities are commonly coadministered to compensate for any shortcomings.
For example, midazolam is primarily an anxiolytic with some amnestic qualities that is often mixed with fentanyl, primarily an analgesic.
Nonetheless, clinicians may underuse sedation, usually from a lack of experience or from unchallenged myths regarding its use.