Can intramuscular (IM) testosterone cause insomnia?

Intramuscular Testosterone and Insomnia

Intramuscular testosterone therapy does not directly cause insomnia, but it can exacerbate or induce sleep apnea which may secondarily lead to sleep disturbances. 1

Relationship Between Testosterone and Sleep

Sleep Architecture Effects

• Testosterone affects the timing of sleep but not its duration, with higher levels potentially leading to later bedtimes 2
• Low testosterone levels are associated with lower sleep efficiency, increased nocturnal awakenings, and less time in slow-wave sleep 3
• Higher testosterone concentrations are positively associated with sleep efficiency in men with normal cortisol levels 4

Sleep Apnea Connection

• Testosterone therapy has been associated with exacerbation of sleep apnea or development of sleep apnea, primarily through central mechanisms rather than anatomical changes in the airway 1
• This effect is more common in men treated with higher doses of parenteral testosterone who have other identifiable risk factors for sleep apnea 1
• Testosterone contributes to sleep-disordered breathing primarily through central mechanisms rather than by means of anatomical changes in the airway 1

Evidence from Clinical Studies

• A randomized controlled trial found that intramuscular testosterone undecanoate (1000 mg) worsened oxygen desaturation index and nocturnal hypoxemia at 7 weeks, but these effects were time-limited and not present at 18 weeks 5
• The worsening of sleep-disordered breathing occurred irrespective of initial testosterone concentrations 5
• In men with obstructive sleep apnea (OSA), low testosterone is more related to obesity rather than the OSA itself 2
• Testosterone treatment only transiently worsens severity of OSA, which need not be considered a contraindication to its use 2

Risk Factors and Monitoring

• Risk factors that should prompt screening for sleep apnea before initiating testosterone therapy include:

  • Obesity 1
  • History of snoring 1
  • Witnessed apneas 1
  • Excessive daytime sleepiness 1
  • Hypertension 1

• Monitoring recommendations during testosterone therapy:

  • Assessment of sleep apnea symptoms at follow-up visits (1-2 months after initiation and every 3-6 months thereafter) 1
  • Vigilance for symptoms of worsening sleep apnea including increased daytime sleepiness, morning headaches, and deterioration in cognitive function 1

Clinical Implications

• Untreated severe OSA has traditionally been considered a contraindication to testosterone therapy 6
• For patients with diagnosed OSA, Continuous Positive Airway Pressure (CPAP) therapy should be initiated before or concurrently with testosterone therapy 6
• Testosterone therapy may be initiated in patients with adequately treated sleep apnea 6

Common Pitfalls to Avoid

• Do not initiate testosterone therapy without screening for sleep apnea in high-risk patients 1
• Do not overlook the importance of weight management, as obesity is a significant risk factor for both OSA and hypogonadism 1
• Do not assume that all sleep disturbances in patients on testosterone therapy are directly caused by the hormone; evaluate for other common causes of insomnia 1
• Do not discontinue testosterone therapy solely based on mild sleep disturbances without proper evaluation for sleep apnea and other potential causes 2

In conclusion, while intramuscular testosterone does not directly cause insomnia, it can exacerbate or induce sleep apnea which may lead to sleep disturbances. Proper screening before initiation and monitoring during therapy are essential to identify and manage these effects.