Where can I find additional information about tadalafil?

Additional information about tadalafil is available  at regulatory websites, including websites  for the US Food and Drug Administration  (FDA), the European Medicines Agency (EMEA),  or from regulatory agencies in your country.  You can find additional information on the  Internet at the official Cialis website: http://  www.cialis.com.  There are also several good books available,  in addition to the articles referenced herein:  Jackson, Sex, the Heart and Erectile Dysfunction;  Eardley and Sethis, Erectile Dysfunction: Current  Investigation and Management; and Shabsigh,  Back to Great Sex: Overcome ED and Reclaim Lost  Intimacy. 

Can tadalafil be taken with amyl nitrate?

No. Amyl nitrate, often referred to as ‘‘poppers,’’  is an organic nitrate. All PDE5 inhibitors  including tadalafil are contraindicated in the  presence of ANY organic nitrate. Men should  be counseled that amyl nitrate and butyl  nitrate, which may be abused recreationally,  are organic nitrates and are therefore also  contraindicated.  Continued Learning 

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. 

Some of my patients with ED taking tadalafil also have ischemic heart disease. Can I prescribe PRN nitrate therapy in case they have chest pain?

No. All PDE5 inhibitor therapy including tadalafil  are contraindicated in men taking any form  of organic nitrates including sublingual and  long-acting nitroglycerin. PDE5 inhibitors  potentiate the hypotensive effect of nitrates.  Nitrate therapy, even if PRN, should not be  prescribed and patients should be instructed  to discard any leftover nitroglycerin tablets  while on PDE5 inhibitor therapy. Patients  with ischemic heart disease who wish to take  a PDE5 inhibitor for the treatment of their ED  should be counseled that in case they have  chest pain they should seek immediate medical  care, they should not take nitroglycerin,  and they should inform the health care provider  that they are on a PDE5 inhibitor, and  when they last took it. Though nitrates are  highly effective in relieving pain associated  with myocardial ischemia, they do not alter  long-term survival [63–65]. 

Can tadalafil be prescribed to men with ED who are on one or more antihypertensives?

Tadalafil can be prescribed to men with ED  who are on one or more antihypertensives,  with the exception of those alpha-blockers  which are used to treat hypertension. However,  appropriate clinical advice should be  given to patients regarding a possible decrease  in blood pressure when they are being treated  with antihypertensive medications and taking  a PDE5 inhibitor.  Tadalafil has been studied with concomitant  use of antihypertensive medications  because many patients who experience erectile  dysfunction also have hypertension. Specific  drug-interaction studies, examining the use of  tadalafil and commonly prescribed oral antihypertensive  agents, and extensive safety data  from patients taking tadalafil and oral antihypertensives  concomitantly, demonstrate that  tadalafil is generally safe in patients receiving  one or more concomitant antihypertensive  agents [61,62].  Studies have been conducted to test the  interaction of tadalafil with antihypertensive  agents including amlodipine besylate (Norvasc1),  metoprolol (Toprol-XL1), bendrofluazide,  enalapril maleate (Vasotec1), or  angiotensin II receptor blockers. No clinically  significant interactions were observed.