If my patient has chest pain while on tadalafil, how should he be treated in the emergency room?

Administration of nitrates to a patient on any  PDE5 inhibitor, including tadalafil, is contraindicated.  Physicians and paramedics need to  be aware of this potentially serious interaction.  Thus, if a patient presents with chest  pain, it will be imperative to question whether  the patient has used a PDE5 inhibitor and the  Supplement  154 Vol. 2, No. 1, pp. 141–157, March 2005  timing of any such use. In a drug-interaction  study, the hemodynamic interaction between  tadalafil and sublingual nitroglycerin lasted  24 hours, but was not seen at 48 hours [66].  If the man has taken tadalafil within 48 hours,  then organic nitrates should not be given. If  nitrates are deemed medically necessary in a  life-threatening situation 48 hours or more  after the use of tadalafil, they should be administered  under medical supervision with  hemodynamic monitoring. If the chest pain  is secondary to myocardial ischemia, then  treatment other than nitrates should be instituted  immediately. These include beta-blockers,  calcium channel blockers, morphine,  oxygen, aspirin, heparin, percutaneous coronary  intervention, and/or thrombolytic therapies.  Physician judgment should guide the  selection of the most appropriate treatment  modality for the patient.  According to ACC/AHA guidelines, where  there is no contraindication, antiplatelet therapy  should be initiated with aspirin early in  the emergency care of patients with acute  coronary syndrome [67]. Tadalafil does not  potentiate the increase in bleeding time  caused by aspirin.