Master Your Sleep

Sleep apnea (or sleep apnoea in British English) is a sleep disorder characterized by pauses in breathing during sleep.

Types of sleep apnea

• Obstructive sleep apnea is the most common type of sleep apnea. It happens when the upper airway becomes blocked during sleep. Most frequently, the blockage of airways happens when the soft tissue in the back of the throat collapses and closes the throat during the night. Another blockage happens when throat muscles are relaxed, and there is only a narrow airway in place. At this time, a large tongue or abnormal tissue in the throat can also block the airway.
• Central apnea and mixed apnea are other types of sleep apnea, but are uncommon. In case of central sleep apnea there is a part of the brain, which controls our breathing mechanism, doesn’t work appropriately.  

No clear guidelines are available on when or whether to treat central sleep apnea.

One of the most important methods of treating sleep apnea is through continuous positive airway pressure or more commonly known as CPAP.

Sleep Apnea Treatment

Several different treatments have been described:

• Treatment of the underlying cause, such as:
  • positive airway pressure (PAP)
  • adaptive servo ventilation (ASV)
  • oxygen
  • acetazolamide
  • sedative-hypnotics
  • theophylline
  • added dead space
  • carbon dioxide inhalation

Sleep Apnea Medication

Attention should be given to treatment of other predisposing factors such as nasal obstruction. The followong medication is recommended: 

• Acetazolamide (Diamox): Acetazolamide is a carbonic anhydrase inhibitor that causes bicarbaturia and metabolic acidosis, which presumably shifts the apneic threshold of PaCO₂ to a lower level.
  • It has been shown to be effective therapy in primary central sleep apnea and CSB in patients with heart failure and in the treatment of high-altitude periodic breathing
  • While increased respiratory drive may uncover obstructive sleep apnea, and because most central sleep apnea patients have obstructive sleep apnea, follow-up PSG is suggested after the initiation of acetazolamide therapy
• Theophylline
  • Theophylline has been studied in patients with heart failure and was found to be effective in attenuating CSB
  • It is also effective for high-altitude periodic breathing
• Temazepam and zolpidem have been shown to be effective in treating nonhypercapnic central sleep apnea and are believed to work by consolidating the sleep pattern, thus minimizing the instability in ventilation induced by sleep-wake transitions.

Carbonic Anhydrase Inhibitor

• To induce metabolic acidosis and increase baseline ventilation

Acetazolamide (Diamox)

• Carbonic anhydrase inhibitor for acclimatization to altitude in HACE and AMS
• Helps prevent AMS in forced rapid ascent or in patients with history of repeated AMS
• Improves symptomatic periodic breathing and hypoxia experienced at high altitudes
• Not indicated for general prophylaxis of AMS
• Treatment of AMS may be discontinued when patient is asymptomatic

Benzodiazepines

• To promote deeper stages of sleep

Temazepam (Restoril)

• Intermediate rate of absorption and duration of action make this drug useful for treating initial and middle insomnia.
• Has no active metabolites, which reduce cognitive impairment and grogginess the following day

Nonbenzodiazepine sedative hypnotic

• To consolidate sleep

Zolpidem (Ambien)

• Rapidly absorbed, with fast onset of action (20-30 min), which makes this a good drug for sleep induction.
• The ER product (Ambien CR) consists of a coated 2-layer tab and is useful for insomnia characterized by difficulties with sleep onset and/or sleep maintenance
• First layer releases drug content immediately to induce sleep, whereas second layer gradually releases additional drug to provide continuous sleep

Phosphodiesterase inhibitor

• Respiratory stimulant

Theophylline (Theo-dur)

• Has a number of physiological effects, including increases in collateral ventilation, respiratory muscle function, mucociliary clearance, and central respiratory drive
• Partially acts by inhibiting phosphodiesterase, elevating cellular cyclic AMP levels, or antagonizing adenosine receptors in bronchi, resulting in relaxation of smooth muscle
• Note: clinical efficacy is controversial, especially in acute setting