tranylcypromine raises toxicity of fentanyl transdermal by Other (see remark). Contraindicated. Comment: Stay clear of fentanyl in patients who require concomitant administration MAOIs, or inside of 14 days of stopping an MAOI. Extreme and unpredictable potentiation by MAO inhibitors has long been described with opioid analgesics.fentanyl transderm