Uncovering the role of opioids in sexual dysfunction is a difficult task. The interaction between many variables, including chronic pain, depression, and smoking make it a hard question to answer.
Here are some key points about opioid use and erectile dysfunction. More detail and supporting information is in the main article.
- Many factors can influence erectile dysfunction, including smoking and depression
- One study concluded that 20 percent of patients receiving high-dose long-term opioids had evidence of sexual dysfunction
- Long-term opioid use may also cause female sexual dysfunction, but evidence is scarce
Decreased sex hormone levels
Opioid use may decrease levels of sex hormones.
In 2016, the United States Food & Drug Administration (FDA) issued a warning regarding severe safety issues associated with opioid pain medications.
Among new warnings on impeded renal gland function and central nervous system reactions, the FDA report declared that:
"Long-term use of opioids may be associated with decreased sex hormone levels and symptoms such as reduced interest in sex, impotence, or infertility."
The FDA based their decision on a review of published studies that assessed the levels of sex hormones in people who were chronic users of opioids; they also pointed out that some brands of opioids already carry warnings of this risk.
However, the FDA cautioned that all of the studies they reviewed on the relationship between chronic opioid use "had limitations that make it difficult to determine whether the symptoms were caused by the opioids or other factors."
It is known that sexual dysfunction is a common problem among people who suffer from chronic pain. Despite this, there is a relative lack of literature on the subject, possibly because it is not usual for doctors to inquire about the sexual health of patients presenting with symptoms of chronic pain. As such, it has been difficult to say with certainty whether painkillers are causing sexual dysfunction, or if it is something else.
For instance, one potentially confounding factor that may have previously masked an association between sexual dysfunction and opioid use is depression. Depression is associated with sexual dysfunction, and people with depression are also thought to be more likely to use opioids, but studies have also shown that opioids may cause or exacerbate depression.
So, is it depression or opiate use - or both - that are affecting sexual function, or is opiate use worsening depression, which, in turn, damages sexual health?
Similarly, smoking has been associated both with prescription opioid use and with erectile dysfunction, so if someone has erectile dysfunction and smokes it can be difficult to determine which factor has the biggest influence.
Men taking opioids 'more likely to use erectile dysfunction treatments'
A 2013 study, published in the journal Spine, found that long-term male users of opioids were significantly more likely to also use treatments for erectile dysfunction and hormone replacement therapies, compared with men who did not use opioids.
The study looked at 11,327 adult men who had been diagnosed with back pain. The researchers found that 909 of these men had received medications for sexual dysfunction. The men were also significantly older than those with back pain who had not received treatment for sexual dysfunction, and were more likely to smoke, have depression, and to use sedative-hypnotic medications.
From this data, the researchers calculated that nearly 20 percent of patients receiving high-dose long-term opioids had evidence of sexual dysfunction.
But what is driving this link between the use of painkillers and sexual dysfunction?
One mechanism behind the association may be that opioids affect the function of hormones in the hypothalamic-pituitary-gonadal (HPG) pathways that control the production of sex hormones via the secretion of gonadotropin-releasing hormone (GnRH).
Opioids inhibit GnRH, which leads to a decrease in the production of luteinizing hormone (LH). Decreased levels of LH, in turn, inhibit production of testosterone, which - in both men and women - can cause depression and sexual dysfunction.
Are female opioid users at risk?
In addition to the issue of decreased testosterone production, we also know that opioids have a negative effect on adrenal androgen production, which has been found to decrease sexual desire, sexual receptivity, and pleasure in some women. So, if there are several biological mechanisms related to opioid use that affect female sexual health, to what extent are women who use opioid painkillers at risk?
Data on associations between female sexual dysfunction and opioid use is scarce. However, one study published in the Journal of Clinical Endocrinology and Metabolism reported that decreased libido or impotence was found in 23 of 24 male participants receiving opioids, compared with decreased libido in just 22 of 32 female participants receiving opioids. In this study, the participants were receiving opioids via the spine for the long-term control of chronic intractable pain.
Because of the lack of research on this subject among female patients, doctors are less certain about what treatments might help women who have opioid-related sexual dysfunction. However, androgen treatment might be beneficial, and the oral contraceptive pill could also help younger women.
For men, testosterone supplementation is the primary treatment, though in some cases erectile dysfunction drugs such as sildenafil (Viagra), tadalafil, or vardenafil may be more suitable.
Opioid prescriptions are escalating in the U.S.
The escalating use of opioid painkillers is currently a major source of concern; overdose deaths from these prescription drugs and illegal opiates have nearly quadrupled in the U.S. since 1999.
Recently, a study published in JAMA Internal Medicine found that more than half of patients who have prescribed opioids hold on to leftover pills rather than getting rid of them. What is more, 20 percent of participants revealed that they had shared their pills with another person.
"The fact that people are sharing their leftover prescription painkillers at such high rates is a big concern," senior study author Prof. Colleen L. Barry, Ph.D. said. "It's fine to give a friend a Tylenol if they're having pain, but it's not fine to give your OxyContin to someone without a prescription."
"If we don't change our approach," Prof. Barry warned, "we are going to continue to see the epidemic grow."
In their recent safety warning, the FDA urge any patients to inform their healthcare professionals if they experience symptoms of low libido, impotence, erectile dysfunction, lack of menstruation, or infertility.