Is there a cross tolerance among opiates?

Yes, there is cross-tolerance among opiates, meaning that tolerance developed to one opioid can extend to others within the same class. This occurs because they all act on the same opioid receptors in the brain. For example, a person who has developed a tolerance to morphine may also exhibit a reduced response to other opioids like oxycodone or fentanyl. However, the degree of cross-tolerance can vary between different opioids.