Drugs that can Impair Respiration
Alcohol, when ingested while awake, can lead to reduction of both hypoxic and hypercapnic ventilatory responses. Irregular breathing with transient apneas can develop. When ingested close to bedtime, it depresses the upper airway muscle tone and may precipitate or aggravate a pre-existing obstructive sleep apnea; the latter is generally most evident during the first 1 to 3 hours of sleep when alcohol levels are at their highest. Hypercapnia and significant hypoxemia can occur with severe intoxication. The risk of sleep-disordered breathing remains elevated in some abstinent alcoholics following long-term habitual alcohol use, possibly caused by residual upper airway muscle dysfunction or central nervous system damage.
Anesthetics can impair the hypoxic ventilatory response, decrease lung volumes, and decrease upper airway muscle tone, all of which can lead to significant deterioration of respiratory status in patients with an existing obstructive sleep apnea or advanced chronic obstructive lung disease.
Narcotics are potent respiratory depressants and, when ingested at bedtime, can diminish upper airway muscle tone, give rise to hypoxemia, and decrease the hypercapnic ventilatory response.
Sedative hypnotics (eg, benzodiazepines or barbiturates) are mild respiratory depressants. Depression of breathing is more pronounced during coingestion with other central nervous system depressants, such as alcohol, or in individuals with an underlying respiratory impairment (eg, severe chronic obstructive pulmonary disease, neuromuscular weakness, or hypoventilation syndromes).
Source : Respiratory Disorders and Sleep, An Issue of Sleep Medicine Clinics (The Clinics: Internal Medicine)
