Tramadol Cimetidine

ALFENTANIL, FENTANYL, PETHIDINE, TRAMADOL CIMETIDINE Cimetidine may t fentanyl, pethidine and tramadol levels Cimetidine inhibits CYP2D6-medi-ated metabolism of these opioids. Ranitidine weakly inhibits CYP2D6 Watch for excessive narcotization... 

No clinically significant interaction appears to occur between ci-metidine and butorphanol (intranasal), hydromorphone, morphine, pethidine or tramadol between famotidine and hydromorphone or between ranitidine and hydromorphone, morphine, or pethidine. However, isolated reports describe adverse reactions in patients taking methadone, morphine or mixed opium alkaloids with cimetidine, or morphine with ranitidine. 

In an unpublished study on file with the manufacturers, cimetidine increased the AUC of tramadol hy 15% to 27% and decreased the total body clearance by 14% to 22% in healthy subjects. The manufacturers say that these changes are not clinically significant. ... 

Relative history of seizure disorder, bipolar disorder (may induce mania), urinary retention, narrow-angle glaucoma, delirium, hyperthyroidism, bradycardia (or drugs that cause bradycardia), or electrolyte disturbance (esp. K+ or Mg ). Use caution in conjunction with other antidepressants (including MAOIs and SSRIs), other anticholinergic medications, drugs that increase plasma levels (phenothiazines, haloperidol, cimetidine), or drugs that lower seizure threshold (esp. tramadol). Use caution in elderly, children/adolescents. 

---