Is it safe to use Cialis (tadalafil) with hypotension (low blood pressure)?

Cialis (Tadalafil) and Low Blood Pressure: Safety Assessment

Direct Answer

Cialis (tadalafil) is contraindicated in patients with hypotension (systolic blood pressure <90/50 mmHg) and should be used with extreme caution in those with borderline low blood pressure, as it causes systemic vasodilation that can result in clinically significant blood pressure drops. 1

Cardiovascular Contraindications and Precautions

Absolute Contraindications

• Tadalafil is not recommended for patients with hypotension (less than 90/50 mm Hg) until blood pressure is stabilized, as the drug has mild systemic vasodilatory properties that result in transient decreases in blood pressure 1

• Patients with severely impaired autonomic control of blood pressure are particularly sensitive to the actions of vasodilators, including PDE5 inhibitors like tadalafil 1

High-Risk Patient Populations to Avoid

The FDA drug label explicitly states tadalafil is not recommended for the following groups until further information is available 1:

• Myocardial infarction within the last 90 days
• Unstable angina or angina occurring during sexual intercourse
• New York Heart Association Class 2 or greater heart failure in the last 6 months
• Uncontrolled arrhythmias or uncontrolled hypertension
• Stroke within the last 6 months

Hemodynamic Effects of Tadalafil

Blood Pressure Impact

• In healthy subjects, tadalafil 20 mg resulted in a mean maximal decrease in supine blood pressure of 1.6/0.8 mm Hg relative to placebo 1

• The blood pressure-lowering effects of tadalafil in healthy volunteers are minimal 2

• However, patients with left ventricular outflow obstruction (e.g., aortic stenosis, idiopathic hypertrophic subaortic stenosis) can be particularly sensitive to the action of vasodilators, including PDE5 inhibitors 1

Critical Drug Interactions Causing Severe Hypotension

Nitrates - Absolute Contraindication

• Tadalafil is absolutely contraindicated with nitrate medications due to profound systemic hypotension risk 3, 1

• Patients should avoid nitrates for at least 48 hours after tadalafil use (compared to 24 hours for sildenafil/vardenafil due to tadalafil's longer half-life of 17.5 hours) 3, 4

• The combination of tadalafil with any nitric oxide donor can lead to life-threatening hypotension 2

• After taking tadalafil, where nitrate administration is deemed medically necessary for a life-threatening situation, at least 48 hours should have elapsed after the last dose before nitrate administration is considered 1

Alpha-Blockers - Use with Extreme Caution

• Tadalafil 20 mg augmented the hypotensive effect of doxazosin by producing a mean maximal decrease in standing systolic blood pressure that was significantly greater than placebo (mean difference of 9.8 mm Hg) 5

• In subjects taking doxazosin plus tadalafil, 28% had standing systolic blood pressure less than 85 mm Hg versus only 6% with doxazosin plus placebo 5

• Tadalafil had little hemodynamic interaction with tamsulosin 0.4 mg, with mean maximal decreases in standing systolic blood pressure similar to placebo 5

• Combination with alpha-blocking agents such as doxazosin may only be considered when patients are hemodynamically stable for a longer period using the lowest dose of tadalafil and with close blood pressure monitoring 2

Antihypertensive Medications

• When tadalafil 10 mg was combined with amlodipine 5 mg daily, the mean reduction in supine systolic/diastolic blood pressure was 3/2 mm Hg compared to placebo 1

• With angiotensin II receptor blockers, tadalafil 20 mg showed differences of 8/4 mm Hg in systolic/diastolic blood pressure compared to placebo 1

• With bendrofluazide 2.5 mg daily, tadalafil 10 mg caused a mean reduction in supine systolic/diastolic blood pressure of 6/4 mm Hg compared to placebo 1

• With enalapril 10-20 mg daily, tadalafil 10 mg caused a mean reduction of 4/1 mm Hg compared to placebo 1

• With sustained-release metoprolol 25-200 mg daily, tadalafil 10 mg caused a mean reduction of 5/3 mm Hg compared to placebo 1

Alcohol Interaction

• When tadalafil 20 mg was administered with alcohol (0.7 g/kg, equivalent to approximately 6 ounces of 80-proof vodka), more patients had clinically significant decreases in blood pressure compared to alcohol alone 1

• Some subjects reported postural dizziness, and orthostatic hypotension was observed with this combination 1

• When tadalafil 20 mg was given with a lower alcohol dose (0.6 g/kg, approximately 4 ounces of 80-proof vodka), orthostatic hypotension was not observed 1

Clinical Recommendations for Safe Use

Pre-Treatment Assessment

• Physicians should consider the cardiovascular status of their patients, since there is a degree of cardiac risk associated with sexual activity 1

• Before prescribing tadalafil, physicians should carefully consider whether their patients with underlying cardiovascular disease could be affected adversely by vasodilatory effects 1, 6

• A complete diagnostic work up and potentially optimized cardiovascular treatment may be necessary before sexual intercourse can be recommended and tadalafil may be prescribed 2

Monitoring and Patient Education

• Patients who experience symptoms such as chest pain, dizziness, or nausea during sexual activity should stop and seek immediate medical attention 1

• All healthcare providers should be informed that the patient takes tadalafil, as the active ingredient can remain in the body for more than 2 days after a single tablet 1

• The active ingredient can remain longer in patients with kidney or liver problems, or those taking certain other medications 1

Common Pitfalls to Avoid

• Never prescribe tadalafil to patients currently using nitrates or who may need nitrates within 48 hours - this is the most critical safety concern 1

• Do not assume all alpha-blockers interact similarly - tamsulosin appears safer than doxazosin when combined with tadalafil 5

• Avoid initiating tadalafil in patients with baseline systolic blood pressure <100 mmHg 3

• Do not overlook the prolonged half-life of tadalafil (17.5 hours) compared to other PDE5 inhibitors when considering drug interactions 3

• Remember that patients with autonomic dysfunction are at particularly high risk for hypotensive episodes 1