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Interactions between Sildenafil and Tadalafil

1 drug interaction and 47 additional warnings found for the following 2 drugs:

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Drug interactions

Major drug interactions

Major:

sildenafil tadalafil

Applies to: sildenafil and tadalafil
Generally avoid

The safety and efficacy of combining a phosphodiesterase-5 (PDE-5) inhibitor with other PDE-5 inhibitors have not been studied. Since these agents have systemic vasodilatory properties, concurrent use may result in additive hypotensive and other cardiovascular adverse effects.

Management

The concurrent use of multiple PDE-5 inhibitors, even if intended for differing indications, should generally be avoided.

References (9)
  1. (2001) "Product Information. Viagra (sildenafil)." Pfizer U.S. Pharmaceuticals
  2. (2003) "Product Information. Levitra (vardenafil)." Bayer
  3. (2003) "Product Information. Cialis (tadalafil)." Lilly, Eli and Company
  4. (2005) "Product Information. Revatio (sildenafil)." Pfizer U.S. Pharmaceuticals Group
  5. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  6. Cerner Multum, Inc. "Australian Product Information."
  7. (2009) "Product Information. Adcirca (tadalafil)." United Therapeutics Corporation
  8. (2012) "Product Information. Stendra (avanafil)." Vivus LLC.
  9. (2014) "Product Information. Staxyn (vardenafil)." Merck & Co., Inc

Therapeutic duplication warnings

Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition.

It can be intentional, when combining drugs with similar actions adds demonstrated therapeutic benefit — or unintentional, such as when a patient sees multiple prescribers or fills prescriptions at more than one pharmacy, which can lead to adverse effects.

Duplication:

Erectile dysfunction agents

The recommended maximum number of medicines in the 'erectile dysfunction agents' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'erectile dysfunction agents' category:

  • sildenafil
  • tadalafil

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

Duplication:

Agents for pulmonary hypertension

The recommended maximum number of medicines in the 'agents for pulmonary hypertension' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'agents for pulmonary hypertension' category:

  • sildenafil
  • tadalafil

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

Food/lifestyle interactions

Moderate food/lifestyle interactions

Moderate:

sildenafil Food/Lifestyle

Applies to: sildenafil
Generally avoid

Coadministration with grapefruit juice may slightly increase the oral bioavailability and delay the onset of action of sildenafil. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In a randomized, crossover study with 24 healthy male volunteers, ingestion of 250 mL of grapefruit juice one hour before and concurrently with a 50 mg dose of sildenafil increased the mean area under the plasma concentration-time curve (AUC) of sildenafil and its pharmacologically active N-desmethyl metabolite by 23% and 24%, respectively, compared to water. Peak plasma concentrations (Cmax) were unaltered, but the time to reach sildenafil Cmax was prolonged by 0.25 hour. The observed increase in sildenafil bioavailability is unlikely to be of clinical significance in most individuals. However, pharmacokinetic interactions involving grapefruit juice are often subject to a high degree of interpatient variability and may be significant in the occasional susceptible patient. Indeed, one subject in the study had a 2.6-fold increase in sildenafil concentrations.

Management

It may be advisable to avoid administration of sildenafil with grapefruit juice to prevent potential toxicity and delay in onset of action.

References (1)
  1. Jetter A, Kinzig-Schippers M, Walchner-Bonjean M, et al. (2002) "Effects of grapefruit juice on the pharmacokinetics of sildenafil." Clin Pharmacol Ther, 71, p. 21-29
Moderate:

tadalafil Food/Lifestyle

Applies to: tadalafil
Generally avoid

Coadministration with grapefruit juice is likely to increase the plasma concentrations of tadalafil, which is primarily metabolized by CYP450 3A4. However, the interaction has not been studied. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit.

Monitor

Additive hypotensive effects may occur when phosphodiesterase-5 (PDE5) inhibitors such as tadalafil are used with alcohol, as both are mild systemic vasodilators. In clinical pharmacology studies, more subjects administered alcohol at a dose of 0.7 g/kg (equivalent to approximately 6 ounces of 80-proof vodka in an 80-kg male; consumed within 10 minutes in study subjects, providing blood alcohol levels of 0.08%) in combination with tadalafil 10 or 20 mg single doses had clinically significant decreases in blood pressure than with alcohol alone. There were reports of postural dizziness, and orthostatic hypotension was observed in some. When tadalafil 20 mg was administered with alcohol at a lower dose of 0.6 g/kg (equivalent to approximately 4 ounces of 80-proof vodka in an 80-kg male), orthostatic hypotension was not observed, dizziness occurred with similar frequency relative to alcohol alone, and the hypotensive effects of alcohol were not potentiated. Neither tadalafil nor alcohol affected the plasma concentrations of the other.

Management

Caution is recommended with concurrent consumption of large amounts of alcohol in patients taking tadalafil as it may increase the potential for orthostatic signs and symptoms, such as increase in heart rate, decrease in standing blood pressure, dizziness, and headache. It may also be appropriate to avoid consuming large amounts of grapefruit juice.

References (8)
  1. (2009) "Product Information. Adcirca (tadalafil)." United Therapeutics Corporation
  2. (2024) "Product Information. Opsynvi (macitentan-tadalafil)." Actelion Pharmaceuticals US Inc
  3. (2023) "Product Information. Adcirca (tadalafil)." Eli Lilly and Company Ltd
  4. (2024) "Product Information. Opsynvi 10/40 (macitentan-tadalafil)." Janssen-Cilag Pty Ltd
  5. (2025) "Product Information. Opsynvi (macitentan-tadalafil)." Janssen Inc
  6. (2019) "Product Information. Tadalafil (tadalafil)." Amneal Pharmaceuticals LLC
  7. (2021) "Product Information. Ach-Tadalafil (tadalafil)." Accord Healthcare Inc
  8. (2024) "Product Information. Cialis (tadalafil)." Eli Lilly Australia Pty Ltd

Disease interactions

43 potential interactions Applies to: 23 conditions, including Seizures, Hypotension, Pulmonary Edema, Tinnitus, and Peptic Ulcer.

Alcoholism

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Alcoholism.

Alcohol consumption may intensify the pressure-lowering effects of mild vasodilators, such as phosphodiesterase 5 (PDE5) inhibitors. Therefore, patients that consume alcohol should be warned to limit alcohol intake while receiving these agents.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Alcoholism.

Alcohol consumption may intensify the pressure-lowering effects of mild vasodilators, such as phosphodiesterase 5 (PDE5) inhibitors. Therefore, patients that consume alcohol should be warned to limit alcohol intake while receiving these agents.

Bleeding Associated with Coagulation Defect

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Bleeding Associated with Coagulation Defect.

The safety of sildenafil in patients with bleeding disorders or active peptic ulceration is unknown. In clinical studies, the incidence of bleeding (i.e., epistaxis) was increased in patients with pulmonary arterial hypertension secondary to connective tissue disease and in patients on concomitant therapy with an oral vitamin K antagonist. There have been postmarketing reports of bleeding events in patients treated with sildenafil for erectile dysfunction.

Bleeding Disorder

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Bleeding Disorder.

The safety of sildenafil in patients with bleeding disorders or active peptic ulceration is unknown. In clinical studies, the incidence of bleeding (i.e., epistaxis) was increased in patients with pulmonary arterial hypertension secondary to connective tissue disease and in patients on concomitant therapy with an oral vitamin K antagonist. There have been postmarketing reports of bleeding events in patients treated with sildenafil for erectile dysfunction.

Cardiovascular Conditions and Disorders

Major:

sildenafil

Sildenafil has a major potential interaction with Cardiovascular Conditions and Disorders.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Major:

tadalafil

Tadalafil has a major potential interaction with Cardiovascular Conditions and Disorders.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Cerebral Vascular Disorder

Major:

sildenafil

Sildenafil has a major potential interaction with Cerebral Vascular Disorder.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Major:

tadalafil

Tadalafil has a major potential interaction with Cerebral Vascular Disorder.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Hearing Loss

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Hearing Loss.

Use of phosphodiesterase-5 (PDE5) inhibitors has been associated with sudden decrease or loss of hearing, which may be accompanied by tinnitus or dizziness. Patients with hearing problems should stop taking these agents and seek prompt medical care.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Hearing Loss.

Use of phosphodiesterase-5 (PDE5) inhibitors has been associated with sudden decrease or loss of hearing, which may be accompanied by tinnitus or dizziness. Patients with hearing problems should stop taking these agents and seek prompt medical care.

History - Cerebrovascular Disease

Major:

sildenafil

Sildenafil has a major potential interaction with History - Cerebrovascular Disease.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Major:

tadalafil

Tadalafil has a major potential interaction with History - Cerebrovascular Disease.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

History - Myocardial Infarction

Major:

sildenafil

Sildenafil has a major potential interaction with History - Myocardial Infarction.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Major:

tadalafil

Tadalafil has a major potential interaction with History - Myocardial Infarction.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Hypotension

Major:

sildenafil

Sildenafil has a major potential interaction with Hypotension.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Major:

tadalafil

Tadalafil has a major potential interaction with Hypotension.

The use of phosphodiesterase-5 (PDE5) inhibitors is not recommended in patients with preexisting cardiovascular disease for whom sexual activity is inadvisable due to the potential cardiac risk. Physicians should also consider the vasodilatory effect of these drugs and whether they may adversely affect patients with underlying cardio- and/or cerebrovascular conditions, in particular those who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; those with resting hypotension (BP < 90/50) or hypertension (BP > 170/110); and those with unstable angina associated with cardiac failure or coronary artery disease. There are no controlled clinical data on the safety or efficacy in such patients. Other adverse cardiovascular effects reported include angina pectoris, myocardial infarction, AV block, ventricular arrhythmia, tachycardia, palpitation, hypotension, postural hypotension, syncope, cerebral thrombosis, cerebrovascular hemorrhage, transient ischemic attack, cardiac arrest, heart failure, and hypertension. Many of these events occurred in patients with cardiovascular risk factors and during or shortly after sexual activity.

Liver Disease

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Liver Disease.

Phosphodiesterase 5 (PDE-5) inhibitors are cleared predominantly by hepatic metabolism. The pharmacokinetic disposition of these agents has not been assessed in patients with severe hepatic impairment. No dosage modification is recommended for patients with mild to moderate hepatic impairment, however, therapy with these agents should not be administered to patients with severe hepatic impairment. In patients with mild hepatic impairment a lower dose of these agents should be used as initial therapy.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Liver Disease.

Phosphodiesterase 5 (PDE-5) inhibitors are cleared predominantly by hepatic metabolism. The pharmacokinetic disposition of these agents has not been assessed in patients with severe hepatic impairment. No dosage modification is recommended for patients with mild to moderate hepatic impairment, however, therapy with these agents should not be administered to patients with severe hepatic impairment. In patients with mild hepatic impairment a lower dose of these agents should be used as initial therapy.

Myeloproliferative Disorders

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Myeloproliferative Disorders.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Myeloproliferative Disorders.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Optic Nerve Disorder

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Optic Nerve Disorder.

Sildenafil for the treatment of erectile dysfunction (ED) should be used with caution and only if the benefit outweighs the risk in patients with a history of non-arteritic anterior ischemic optic neuropathy (NAION) or with retinitis pigmentosa. Use of sildenafil for the treatment of pulmonary arterial hypertension is not recommended in patients with retinitis pigmentosa. Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking sildenafil; patients taking sildenafil for ED should immediately stop treatment. Most patients who developed NAION during therapy with sildenafil had underlying anatomic or vascular risk factors, including low cup to disc ratio ("crowded disc").

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Optic Nerve Disorder.

Tadalafil for the treatment of erectile dysfunction (ED) should be used with caution and only if the benefit outweighs the risk in patients with a history of non-arteritic anterior ischemic optic neuropathy (NAION) or with retinitis pigmentosa. Use of tadalafil for the treatment of pulmonary arterial hypertension is not recommended in patients with retinitis pigmentosa. Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking tadalafil; patients taking tadalafil for ED should immediately stop treatment. Most patients who developed NAION during therapy with tadalafil had underlying anatomic or vascular risk factors, including low cup to disc ratio ("crowded disc").

Penis Disorders

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Penis Disorders.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Penis Disorders.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Peptic Ulcer

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Peptic Ulcer.

The safety of sildenafil in patients with bleeding disorders or active peptic ulceration is unknown. In clinical studies, the incidence of bleeding (i.e., epistaxis) was increased in patients with pulmonary arterial hypertension secondary to connective tissue disease and in patients on concomitant therapy with an oral vitamin K antagonist. There have been postmarketing reports of bleeding events in patients treated with sildenafil for erectile dysfunction.

Peyronie Disease

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Peyronie Disease.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Peyronie Disease.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Pulmonary Edema

Major:

tadalafil

Tadalafil has a major potential interaction with Pulmonary Edema.

Tadalafil tablet for the treatment of pulmonary arterial hypertension (PAH) should not be used in patients with pulmonary veno-occlusive disease (PVOD) as it may significantly worsen the cardiovascular status of these patients. If signs of pulmonary edema develop during therapy, the possibility of associated PVOD should be considered.

Pulmonary Heart or Vascular Disease

Major:

tadalafil

Tadalafil has a major potential interaction with Pulmonary Heart or Vascular Disease.

Tadalafil tablet for the treatment of pulmonary arterial hypertension (PAH) should not be used in patients with pulmonary veno-occlusive disease (PVOD) as it may significantly worsen the cardiovascular status of these patients. If signs of pulmonary edema develop during therapy, the possibility of associated PVOD should be considered.

Renal Dysfunction

Major:

tadalafil

Tadalafil has a major potential interaction with Renal Dysfunction.

The plasma clearance of phosphodiesterase-5 (PDE5) inhibitors may be decreased in patients with severe renal impairment, resulting in drug accumulation. Therapy with these agents should be avoided in patients with severe renal disease or on renal dialysis. Dose adjustments might be needed based on individual renal assessment and tolerability if used in these patients.

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Renal Dysfunction.

Exposure to sildenafil is increased in patients with renal dysfunction. Lower starting doses of sildenafil for the treatment of erectile dysfunction (ED) are recommended in patients with severe renal impairment (CrCl less than 30 mL/min). When sildenafil is used for the treatment of pulmonary arterial hypertension, no dose adjustment is recommended for any degree of renal impairment.

Retinitis Pigmentosa

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Retinitis Pigmentosa.

Sildenafil for the treatment of erectile dysfunction (ED) should be used with caution and only if the benefit outweighs the risk in patients with a history of non-arteritic anterior ischemic optic neuropathy (NAION) or with retinitis pigmentosa. Use of sildenafil for the treatment of pulmonary arterial hypertension is not recommended in patients with retinitis pigmentosa. Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking sildenafil; patients taking sildenafil for ED should immediately stop treatment. Most patients who developed NAION during therapy with sildenafil had underlying anatomic or vascular risk factors, including low cup to disc ratio ("crowded disc").

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Retinitis Pigmentosa.

Phosphodiesterase-5 (PDE5) inhibitors have been associated with transient impairment of color discrimination (blue/green) and blue- or color-tinged vision. These agents also inhibit phosphodiesterase-6 (PDE6), to a much lesser extent, which is involved in phototransduction in the retina. There are no controlled clinical data on the safety in patients with retinitis pigmentosa, a minority of whom may have genetic disorders of retinal phosphodiesterases. Therapy with these agents should be avoided in such patients.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Retinitis Pigmentosa.

Tadalafil for the treatment of erectile dysfunction (ED) should be used with caution and only if the benefit outweighs the risk in patients with a history of non-arteritic anterior ischemic optic neuropathy (NAION) or with retinitis pigmentosa. Use of tadalafil for the treatment of pulmonary arterial hypertension is not recommended in patients with retinitis pigmentosa. Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking tadalafil; patients taking tadalafil for ED should immediately stop treatment. Most patients who developed NAION during therapy with tadalafil had underlying anatomic or vascular risk factors, including low cup to disc ratio ("crowded disc").

Seizures

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Seizures.

The use of phosphodiesterase 5 (PDE-5) inhibitors has been associated with seizures. Therapy with these agents should be administered cautiously in patients with preexisting seizure disorders.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Seizures.

The use of phosphodiesterase 5 (PDE-5) inhibitors has been associated with seizures. Therapy with these agents should be administered cautiously in patients with preexisting seizure disorders.

Sickle Cell Anemia

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Sickle Cell Anemia.

The safety and efficacy of sildenafil for the treatment of pulmonary hypertension secondary to sickle cell disease has not been established; vaso-occlusive crises requiring hospitalization were more commonly reported in this population.

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Sickle Cell Anemia.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Sickle Cell Anemia.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours) have been reported during treatment with phosphodiesterase-5 (PDE 5) inhibitors. Priapism may result in penile tissue damage and permanent loss of potency if not treated promptly. These agents should be used cautiously in patients with conditions that may predispose them to priapism such as sickle cell anemia, multiple myeloma, or leukemia, and those with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease). If an erection persists longer than 4 hours, the patient should seek immediate medical assistance.

Tinnitus

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Tinnitus.

Use of phosphodiesterase-5 (PDE5) inhibitors has been associated with sudden decrease or loss of hearing, which may be accompanied by tinnitus or dizziness. Patients with hearing problems should stop taking these agents and seek prompt medical care.

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Tinnitus.

Use of phosphodiesterase-5 (PDE5) inhibitors has been associated with sudden decrease or loss of hearing, which may be accompanied by tinnitus or dizziness. Patients with hearing problems should stop taking these agents and seek prompt medical care.

Visual Defect/Disturbance

Moderate:

sildenafil

Sildenafil has a moderate potential interaction with Visual Defect/Disturbance.

Sildenafil for the treatment of erectile dysfunction (ED) should be used with caution and only if the benefit outweighs the risk in patients with a history of non-arteritic anterior ischemic optic neuropathy (NAION) or with retinitis pigmentosa. Use of sildenafil for the treatment of pulmonary arterial hypertension is not recommended in patients with retinitis pigmentosa. Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking sildenafil; patients taking sildenafil for ED should immediately stop treatment. Most patients who developed NAION during therapy with sildenafil had underlying anatomic or vascular risk factors, including low cup to disc ratio ("crowded disc").

Moderate:

tadalafil

Tadalafil has a moderate potential interaction with Visual Defect/Disturbance.

Tadalafil for the treatment of erectile dysfunction (ED) should be used with caution and only if the benefit outweighs the risk in patients with a history of non-arteritic anterior ischemic optic neuropathy (NAION) or with retinitis pigmentosa. Use of tadalafil for the treatment of pulmonary arterial hypertension is not recommended in patients with retinitis pigmentosa. Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking tadalafil; patients taking tadalafil for ED should immediately stop treatment. Most patients who developed NAION during therapy with tadalafil had underlying anatomic or vascular risk factors, including low cup to disc ratio ("crowded disc").

More resources

sildenafil

A total of 396 drugs are known to interact with sildenafil.

tadalafil

A total of 374 drugs are known to interact with tadalafil.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.