Comprehensive guide to opioid medications for pain management
Opioid analgesics are usually used to relieve moderate to severe pain particularly of visceral origin. Repeated use of opioid analgesics can result in tolerance and dependence, although this is less relevant in the acute clinical context. Opioid dependent patients may require much higher doses of opioids to control their pain.
Clinical Note: Always balance pain relief benefits against risks of dependence, side effects, and respiratory depression.
Do not prescribe opioids to people who have:
Prescribe opioids with caution in people with the following conditions (reduced doses often required):
| Condition | Rationale for Caution |
|---|---|
| Impaired respiratory function/asthma | Increased risk of respiratory depression |
| Renal impairment | Increased and prolonged effects |
| Hepatic impairment | Sedation/constipation may precipitate encephalopathy |
| Prostatic hyperplasia | Risk of urinary retention |
| Bowel disorders | Reduced gastric motility exacerbates conditions |
| Biliary tract disease | Risk of ureteric/biliary spasm |
| Convulsive disorders | Avoid tramadol in uncontrolled epilepsy |
| Adrenocortical insufficiency/Hypothyroidism | Reduced dose recommended |
| Elderly/debilitated patients | Increased sensitivity, reduced dose required |
Dependence and Tolerance: Repeated use can lead to physical dependence and tolerance, requiring dose escalation for same analgesic effect.
All opioids interact with CNS depressants - risk of potentiated respiratory depression and sedation.
| Drug Class | Interaction Effect |
|---|---|
| SSRIs & SNRIs | Increased risk of seizures and serotonin syndrome |
| Tricyclic antidepressants | Increased seizure risk |
| Carbamazepine | Reduces serum tramadol levels |
| Warfarin | Increased anticoagulant effects |
Naloxone Notes: Short half-life may require repeated dosing. Monitor for re-sedation after initial reversal.