The purpose of this study is to evaluate the efficacy of testosterone replacement therapy in men with low testosterone due to opioid treatment on body composition, the haemostatic system, glucose metabolism, muscle function, pain sensitivity, pain modulation, lipids, sexual function and quality of life.

Male patients on opioids for non-malignant diseases aged 18-59 years diagnosed with hypogonadotrophic hypogonadism, referred from day hospitals and outpatient populations. 40 patients are randomized to either testosterone undecanoate i.m. or placebo i.m., i.e. 20 patients per arm

A double blinded randomized placebo controlled trial

The study duration is 24 weeks. Patients are treated with Testosterone Undecanoate 1000 mg/4 ml, intramuscular (i.m.) or placebo at 0, 6 and 18 weeks.

Outcome measures will be evaluated at 0 and 14 weeks.

Inclusion Criteria:

• Male patients 18-75 years
• Treatment with opioid for >3 months, daily dose >50-100 mg
• Total testosterone < 12 mmol/L
• Follicle Stimulating Hormone (FSH)/Luteinizing Hormone (LH) levels normal og below normal laboratory values
• Normal prolactin levels

Exclusion Criteria:

• Hematocrit> 54% at screening
• Prostate Specific Antigen (PSA) > 3 ng/ml
• Severe organic and mental disease
• current or present cancer diagnosis
• Previous venous thrombotic embolism and cerebrovascular disease
• Uncontrolled hypertension
• Epilepsy or migraine not adequately controlled by therapy
• Severe benign prostate hypertrophy with symptom score >19
• Sleep apnea
• Alcohol or drug abuse
• Implantation of sustained action sex hormone in the last 12 months
• Use of oral, buccal or transdermal testosterone in the last two weeks
• Treatment with glucocorticoids > 5 mg/day or 5 alfa reductase inhibitors
• Hypersensitivity to Nebido