Strong μ-receptor agonists, variable affinity for δ and κ receptors

Effects: analgesia, relief of anxiety, sedation, slowed GI transit

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Severe pain

Adjunct in anesthesia (fentanyl, morphine)

Pulmonary edema (morphine only)

maintenance and rehab programs (methadone only)

Strong μ-receptor agonists, variable affinity for δ and κ receptors

Effects: analgesia, relief of anxiety, sedation, slowed GI transit

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Severe pain

Adjunct in anesthesia (fentanyl, morphine)

Pulmonary edema (morphine only)

maintenance and rehab programs (methadone only)

Strong μ-receptor agonists, variable affinity for δ and κ receptors

Effects: analgesia, relief of anxiety, sedation, slowed GI transit

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Severe pain

Adjunct in anesthesia (fentanyl, morphine)

Pulmonary edema (morphine only)

maintenance and rehab programs (methadone only)

Strong μ-receptor agonists, variable affinity for δ and κ receptors

Effects: analgesia, relief of anxiety, sedation, slowed GI transit

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Severe pain

Adjunct in anesthesia (fentanyl, morphine)

Pulmonary edema (morphine only)

maintenance and rehab programs (methadone only)

Less efficacious than morphine, can antagonize strong agonists

Effects: like strong agonists but weaker

Similar to strong agonists:

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Cough,  mild to moderate pain

Less efficacious than morphine, can antagonize strong agonists

Effects: like strong agonists but weaker

Similar to strong agonists:

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Mild to moderate pain

Less efficacious than morphine, can antagonize strong agonists

Effects: like strong agonists but weaker

Similar to strong agonists:

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Mild to moderate pain

Less efficacious than morphine, can antagonize strong agonists

Effects: like strong agonists but weaker

Similar to strong agonists:

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Diarrhea, mild to moderate pain

Less efficacious than morphine, can antagonize strong agonists

Effects: like strong agonists but weaker

Similar to strong agonists:

Respiratory depression, severe constipation, addiction liability, convulsions

Nausea, histamine release

Diarrhea, mild to moderate pain

Κ agonist with weak μ antagonist or partial agonist properties

May reduce analgesia or precipitate an explosive abstinence syndrome (when mixed with pure agonist drugs)

Moderate pain

Some maintenance rehab programs

Weak μ agonist, moderate SERT inhibitor, weak NET inhibitor

Analgesia

Seizures (CI in patients with epilepsy)

Moderate pain

Adjunct to opioids in chronic pain syndromes

Poorly understood but strong and partial μ agonists are also effective

Reduces cough reflex

minimal

Acute debilitating cough

Antagonist at μ, δ, and κ receptors

Rapidly antagonizes all opioid effects

Precipitates abstinence syndrome in dependent users

Opioid overdose

Short duration of action (1-2 hours) – severely depressed patient may relapse after one dose