Drug Interactions between Cialis and dutasteride / tamsulosin
This report displays the potential drug interactions for the following 2 drugs:
- Cialis (tadalafil)
- dutasteride/tamsulosin
Interactions between your drugs
tamsulosin tadalafil
Applies to: dutasteride / tamsulosin and Cialis (tadalafil)
Consumer information for this interaction is not currently available.
ADJUST DOSE: Tadalafil may potentiate the hypotensive effect of alpha blockers, resulting in symptomatic hypotension in some patients. Tadalafil inhibits phosphodiesterase-5-mediated degradation of cyclic guanosine monophosphate (cGMP), which in vascular smooth muscles can cause peripheral vasodilation that may be additive with that induced by alpha blockers. In 18 healthy subjects taking doxazosin 8 mg daily for at least 7 days, administration of tadalafil 20 mg resulted in significant augmentation of the blood pressure lowering effect of doxazosin, an alpha-1 adrenergic blocker. Specifically, nine patients given tadalafil had either a standing systolic blood pressure of less than 85 mm Hg or a decrease from baseline of greater than 30 mm Hg at one or more time points, compared to three such patients when given placebo. Two significant adverse events (vertigo and dizziness) potentially related to blood pressure effects were reported with tadalafil, compared to none with placebo. No syncope was reported. In a clinical study of healthy male subjects 45 to 78 years of age, administration of silodosin with a single 20 mg dose of tadalafil resulted in increased frequency of positive orthostatic test results during a 12-hour period following concomitant dosing compared to administration with placebo. No events of symptomatic orthostasis or dizziness were reported in subjects receiving silodosin with tadalafil, a selective alpha-1A adrenergic blocker. No significant adverse events related to decreases in blood pressure were observed when a single dose of tadalafil 10 mg or 20 mg was administered to healthy subjects taking 0.4 mg once-daily tamsulosin, another selective alpha-1A adrenergic blocker.
MANAGEMENT: Caution is advised if tadalafil is used in combination with alpha blockers. Patients who demonstrate hemodynamic instability on alpha blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of tadalafil. Therefore, patients should be stable on alpha blocker therapy prior to initiating tadalafil, and tadalafil should be initiated at the lowest recommended dosage. In those patients already on an optimized dosage of tadalafil, alpha blocker therapy should be initiated at the lowest dosage. Clinicians should bear in mind that the safety of tadalafil in combination with alpha blockers may also be affected by other variables such as intravascular volume depletion and use of other antihypertensive medications. The combination of tadalafil and alpha blockers is not recommended for the treatment of benign prostatic hyperplasia (BPH) due to the lack of safety and efficacy data. Patients on alpha blocker therapy for BPH should discontinue the alpha blocker at least one day prior to starting tadalafil for once-daily use in the treatment of BPH.
References
- "Product Information. Cialis (tadalafil)." Lilly, Eli and Company (2003):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- "Product Information. Rapaflo (silodosin)." Watson Pharmaceuticals (2008):
- "Product Information. Adcirca (tadalafil)." United Therapeutics Corporation (2009):
- "Product Information. Entadfi (finasteride-tadalafil)." Veru Inc (2021):
Drug and food interactions
tamsulosin food
Applies to: dutasteride / tamsulosin
Food may affect the intestinal absorption of tamsulosin. You should take tamsulosin approximately one-half hour following the same meal each day to ensure steady absorption and blood levels of the drug.
tadalafil food
Applies to: Cialis (tadalafil)
Tadalafil can lower blood pressure, and combining it with alcohol may further increase this effect. You may be more likely to experience symptoms such as dizziness, lightheadedness, fainting, flushing, headache, and heart palpitations. You should avoid or limit the use of alcohol while being treated with tadalafil, and use caution when getting up from a sitting or lying position. You may also want to avoid drinking large amounts of grapefruit juice, since it may increase the blood levels and effects of tadalafil. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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