tranylcypromine will increase toxicity of fentanyl transdermal by Other (see comment). Contraindicated. Remark: Stay clear of fentanyl in people who involve concomitant administration MAOIs, or in just 14 days of stopping an MAOI. Intense and unpredictable potentiation by MAO inhibitors has long been reported with opioid analgesics.amobarbital will