Conditions: Hypogonadism Opioid-Related Disorders Male Infertility
Keywords: Chronic pain Low testosterone Hypogonadism Opioid analgesics Narcotics Opioid-induced androgen deficiency OPIAD Male infertility Clomiphene citrate Selective Estrogen Receptor Modulators Testosterone replacement therapy
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 13
Healthy volunteers: no

Brief summary:
The purpose of this randomized controlled clinical trial is to evaluate the effects of clomiphene citrate compared to placebo (substance without active medication) in men who are taking pain medication (opioids) for chronic pain conditions and who have low blood testosterone levels.

The condition of men having low testosterone with long-term pain medication (opioid) usage is called opioid-induced androgen deficiency (OPIAD). Low testosterone can be caused by pain medication effects on part of the brain (hypothalamic-pituitary axis) which ultimately result in decreased testosterone production by the testes. Typical symptoms of low testosterone (hypogonadism) may include decreased muscle mass, increased fat, osteoporosis, anemia, erectile dysfunction, delayed ejaculation. In addition, men with low testosterone may experience decreased attention, and decreased libido, fatigue, and depressed mood. Few studies have looked at hormonal changes caused by long-term opioid usage in men.

Clomiphene citrate, a selective estrogen receptor modulator (SERM) oral medication which inhibits estrogen effects (feedback) on the brain, has been identified by prior studies to raise testosterone in men with low testosterone (due to reasons other than chronic pain medication). Clomiphene citrate is also known to lead to increased sperm production in men with low testosterone unlike testosterone topical or injection medications. Although clomiphene citrate has been studied in hypogonadal men with beneficial outcomes and minimal side effects, no group has previously studied clomiphene citrate as treatment in patients with OPIAD.

Detailed description:
Chronic nonmalignant pain is a widespread issue affecting 15-30% of the population. Many patients with chronic pain are responsive to first-line combination of physical modalities and non-opioid analgesics. Up to 20% of these patients, however, require opioid therapy for adequate pain relief. The use of long-acting opioids, including morphine sulfate, oxycodone, fentanyl, and methadone, although effective for pain control, carries risks of addiction, tolerance, and systemic side effects including nausea, itching, constipation, and hypogonadotropic hypogonadism with consequent testosterone depletion (in up to 86% of patients taking chronic pain medication) leading to the multiple adverse effects. Opioid-induced androgen deficiency (OPIAD), occurs with high frequency and persistence, and commonly remains undiagnosed in the pain clinic. Low testosterone may be treated using exogenous testosterone (topical or gel) or other medications such as selective estrogen receptor modulators (i.e. clomiphene citrate). While both medication types increase serum testosterone levels, clomiphene citrate is known to benefit sperm parameters in hypogonadal men while exogenous testosterone is known to inhibit sperm production. Few studies have examined the hormonal changes caused by long-term opioid usage in men, and no studies have formally studied clomiphene citrate for this patient population.

Arms:
arm 1: The initial dose of clomiphene citrate will be 25 mg (po, pill by mouth) every other day. This will be started at visit 2, week 0 of the study following diagnosis of low baseline testosterone (serum total testosterone \<350 ng/dl in men \<55 years, \<300 ng/dl in men 55-65 years). Clomiphene citrate dose will be titrated up to a maximum of 50 mg daily according to serum total testosterone levels measured at follow-up visits during the 3 month duration of the study. arm 2: Placebo pill will be administered (po, pill by mouth) every other day starting at week 0 of the study in men diagnosed with low testosterone. Treatment will be delayed in these men until the 3 month completion of the study, at which time this group may also receive testosterone replacement therapy.

Interventions: intervention 1: Clomiphene citrate intervention 2: Placebo
Intervention descriptions: intervention 1: None intervention 2: Placebo pill that will have appearance identical to the treatment pill but will not contain active medication.

Protocol document: