What is the effect of opioids on respiratory rate?

Opioids are known to depress the central nervous system, leading to a primary effect of reducing the respiratory rate. This occurs because opioids bind to specific receptors in the brain that regulate respiratory function, particularly the brainstem where the respiratory centers are located. When these receptors are activated, the body's respiratory drive is diminished, causing a decrease in the rate and depth of breathing.

This respiratory depression is a critical aspect of opioid pharmacology and is a key reason for the careful monitoring of patients receiving opioid therapy. Individuals using opioids can experience side effects such as apnea or hypoventilation, making understanding this effect vital for safe medical practice. The other options do not accurately reflect the typically recognized effects of opioids on respiration—opioids do not generally cause an increased or normal respiratory rate, nor do they lead to a variable respiratory rate in a predictable manner, but rather a consistent decrease.