Final answer:
Opioid analgesics can cause respiratory depression, constipation, and dependence. These side effects manifest due to the way opioids interact with the body's receptors, and they have a high potential for abuse and addiction.
Step-by-step explanation:
Opioid analgesics can cause a number of side effects even when taken as directed. Three significant effects that opioids can cause are respiratory depression, which means a reduced breathing rate, constipation, and dependence or addiction. Opioids work by binding to opioid receptors in the body, reducing pain and producing euphoria, which can lead to their high potential for abuse. The risk of addiction is high and can occur even when opioids are used as prescribed. Additionally, overdose can result from taking too many prescription opioids, which can potentially stop a person's breathing and lead to death.