Perioperative Methadone Compared to Placebo in Elderly Hip Fracture Patients

Hip fractures are associated with severe pain and are sustained by the elderly population. Demand for adequate pain relief combined with a low tolerance for analgesic drugs makes the treatment of elderly hip fracture patients difficult. Perioperative methadone could improve the analgesic treatment of these patients. An earlier pilot study showed that 0.10 mg/kg was safe to use. This study further investigates the advantages of methadone. The study's objective is to investigate the analgesic effects of a single dose of methadone given during hip fracture surgery.

Studies investigating the perioperative use of methadone have shown promising analgesic properties. Our pilot study (EudraCT no.: 2022-001857-22) showed that a dosage of 0.10 mg/kg was safe to use and showed excellent analgesic properties. Sufficient management of acute postoperative pain is important in relation to morbidity, hospital costs, and mortality. About 60% of patients undergoing surgical intervention experience moderate to severe postoperative pain. Thus, sufficient analgesic treatment is crucial in the initial postoperative days, which are considered the most painful phase of recovery. Opioids have conventionally been used as an analgesic treatment in this phase. However, this treatment has been accompanied by side effects and addiction. Methadone shares these side effects, however, as methadone only needs to be administered once, the risk of side effects decreases significantly. This study will investigate the analgesic effects of a single dose of methadone given during hip fracture surgery.

The first objective is to investigate the analgesic effect of perioperative methadone compared with a placebo in acute hip fracture surgery. The second objective is to investigate the long-term effects of methadone on continued opioid consumption, pain, and mobility three months after surgery.

The null hypothesis is that there is no difference in postoperative pain, opioid consumption, or related side effects if a patient receives a dose of methadone or placebo during the surgery.

Eligibility Criteria:
Inclusion Criteria:

* Patients diagnosed with an acute hip fracture (incurred \<24 hours ago) on x-rays in the emergency department (ED) at the university hospital of southern Denmark (SHS). This includes collum femoris fractures, pertrochanteric fractures, and subtrochanteric fractures.
* Patients must be able to read and understand Danish.

Exclusion Criteria:

* Multiple fractures or multi-trauma patient
* Previous allergic reactions or hypersensitivity towards methadone hydrochloride or sodium chloride
* Health conditions preventing treatment:

Chronic obstructive pulmonary disease with either past exacerbations or daily symptoms History of acute asthma attacks History of drug-induced eczema Pulmonary hypertension Raised intracranial pressure or recent head injury Pheochromocytoma History of paralytic ileus QT-interval prolongation on electrocardiogram (ECG) Myasthenia gravis Known liver disorder Hypotension (systolic blood pressure \<100 mmHg at admission) Acute pancreatitis Severe kidney disease (GFR ≤10)

* Concurrent administration with MAO inhibitors or within 2 weeks of suspending treatment with these medicinal products
* Concurrent administration of benzodiazepines
* Impaired cognitive function e.g. dementia. Patients must be able to give informed consent and be able to ask for rescue analgesics if needed
* Current opioid addiction or intravenous addiction