| Opioid type | Medications | Notes about therapy |
| Pure agonists | Codeine | Mainstay of therapy for moderate to severe cancer pain. No clinically relevant ceiling effect for analgesia; as dose is raised, analgesic effects increase until analgesia is achieved or dose-limiting side effects supervene. Meperidine and propoxyphene are not preferred due to potential effects of toxic metabolites. Methadone must be used with caution; only clinicians who are knowledgeable about the risks posed by long and variable half-life, unpredictable potency, and potential for QTc prolongation should use this drug without guidance. |
| Hydrocodone | ||
| Dihydrocodeine | ||
| Morphine | ||
| Hydromorphone | ||
| Fentanyl | ||
| Oxycodone | ||
| Oxymorphone | ||
| Levorphanol | ||
| Methadone | ||
| Meperidine | ||
| Mixed agonist-antagonists | Buprenorphine | Agonist-antagonists include mu receptor agonists with lower intrinsic efficacy (partial agonists) and drugs that have agonist effects at one opioid receptor and antagonist effects at another (mixed agonist-antagonists). Most were developed to be less attractive to individuals with the disease of addiction; this characteristic does not rationalize widespread use for cancer pain. All have the potential to induce acute abstinence in patients with physical dependency on agonist opioids. Most of the mixed agonist-antagonists have a ceiling effect for analgesia. However, buprenorphine does not have a ceiling effect. It is available as a transdermal patch and in a buccal formulation and may be of use in relatively opioid-naïve cancer patients. Some mixed agonists-antagonists (pentazocine and butorphanol) have a high risk of psychotomimetic side effects. |
| Butorphanol | ||
| Dezocine | ||
| Nalbuphine | ||
| Pentazocine | ||
| Mixed-mechanism drugs | Tramadol | Centrally acting analgesics that have agonist actions at the mu receptor and block reuptake of monoamines. |
| Tapentadol |
