Comparison of Lormetazepam and Midazolam Used as Sedatives for Patients That Require Intensive Care

Midazolam is almost exclusively metabolized intrahepatically. The methyl-group at position 1 of the imidazole ring is oxidized by liver enzymes. The product is a-OH-midazolam. This reaction is catalyzed by a p450-dependent oxidase in the liver.

Active a-OH-midazolam is inactivated by a biotransformation type II reaction after conjugation. The water soluble, conjugated midazolam can be excreted by the kidney.

During an intensive care treatment, the p450 dependent metabolization is known to be a "bottleneck of elimination" as many drugs are inactivated by this pathway.

As the phase II (glucuronidation) is non-saturable in practice - the phase I reaction limits the metabolic capacity. This leads to unpredictable prolongation of midazolam effects.

In contrast, Lormetazepam is glucuronized directly at its OH-group during a phase II reaction. Since the glucuronidation is non-saturable, Lormetazepam is metabolized with nearly constant kinetics even if repeatedly administered.

Due to the pharmacokinetics we hypothesize that Lormetazepam has an improved controllability compared to midazolam. As this leads to less frequent agitation and over-sedation, we hypothesize that there are multiple beneficial clinical outcomes for patients treated with lormetazepam instead of midazolam.

Inclusion criteria

• Mechanically ventilated ICU patients with the need for sedatives to achieve or maintain the intended target-RASS (surgical/ nonsurgical).
• Age ≥ 18 years
• Patients who are incapable of giving consent at study inclusion: Written informed consent by patient's legal representative or an independent medical consultant, patients give informed consent subsequent if they are capable.
• Patients who are able to give informed consent at study inclusion: Written informed consent by patients for planned postoperative prolonged ventilatory support who undergo heart surgery
• Consensable patients for inclusion: with necessary intubation with analgosedation

Exclusion criteria

• Any bolus administration of benzodiazepines until 72hrs before inclusion (except from premedication due to anaesthesia).
• Continuous administration of benzodiazepines within the last 7 days before start of study drug application
• Titration phase: No way that a target RASS between -3 and 0 can be determined by the attending physician
• Known drug intolerance or allergy against lormetazepam, midazolam or one of the additional components.
• Addictive disorder
• Increased intracranial pressure
• Acute intoxication with alcohol, analgesics, sedatives, antipsychotics (neuroleptics, anti-depressives, lithium).
• Patients with cerebrale Pathology, which changes the controllability of sedation or die consciousness (e.g. patients known mental retardation due to syndromatic disorders or an infantile brain damage)
• Patients with a suspected or secured hypoxic brain damage
• Patients with intracranial surgery during actual hospital care
• Tetraplegic patients
• Myasthenia Gravis
• Cerebellar or spinal Ataxia
• Moribund patients with an expected lifespan of less than 24 hours.
• Sickle cell anaemia
• Thallassemia
• Enzyme related disorders that are associated with a severe decreased activity of UDP-glucoronyltransferase (e.g. M. Crigler- Najjar)
• Chronic liver insufficiency CHILD C with MELD Score > 17 before access to intensive care unit
• Diagnosed propofol intolerance/anamnestic propofol infusion Syndrome
• Known depression/suicidality
• Pregnancy (positive beta-HCG test from urine or positive beta-HCG laboratory test from serum (in anuric patients the serum beta-HCG test is obliged) or lactation
• Woman of child-bearing potential who are not using a highly effective contraception (Pearl - Index <1) until 3 months after study inclusion and during this trial
• Referral following an order of official authorities (court order or administrative decision) according to German Drug Law (AMG)

§40 (1) 4

• Participation in clinical trials according to the German Drug Law (AMG) 30 days to and during the study
• Local staff