Cialis - Side Effects & Drug Interactions

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Both alcohol and CIALIS, a PDE5 inhibitor, act as mild vasodilators. When mild vasodilators are taken in combination, blood-pressure-lowering effects of each individual compound may be increased. Substantial consumption of alcohol (e. g., 5 units or greater) in combination with CIALIS can increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache.

Anti-Hypertensives PDE5 inhibitors, including tadalafil, are mild systemic vasodilators. Clinical pharmacology studies were conducted to assess the effect of tadalafil on the potentiation of the blood-pressure-lowering effects of selected anti-hypertensive medications.

Alpha Blockers Doxazosin —

When tadalafil 20 mg was administered to healthy subjects taking doxazosin (8 mg daily), an alpha[ 1]-adrenergic blocker, there was significant augmentation of the blood-pressure-lowering effect of doxazosin.

Tamsulosin —

In a clinical pharmacology study, when a single dose of tadalafil 20 mg was administered to healthy subjects taking 0.4 mg once-daily tamsulosin, a selective alpha[ 1A]-adrenergic blocker, no significant decreases in blood pressure were observed. Therefore, based upon significant augmentation of the blood-pressure-lowering effect of doxazosin, an alpha[ 1]-adrenergic blocker, and no significant effect seen with 0.4 mg once-daily tamsulosin, a selective alpha[ 1A]-adrenergic blocker, administration of CIALIS to patients taking any alpha-adrenergic blocker other than 0.4 mg once-daily tamsulosin is contraindicated. Other Anti-Hypertensive Agents

Amlodipine —

A study was conducted to assess the interaction of amlodipine (5 mg daily) and tadalafil 10 mg. There was no effect of tadalafil on amlodipine blood levels and no effect of amlodipine on tadalafil blood levels. The mean reduction in supine systolic/ diastolic blood pressure due to tadalafil 10 mg in subjects taking amlodipine was 3/ 2 mm Hg, compared to placebo. In a similar study using tadalafil 20 mg, there were no clinically significant differences between tadalafil and placebo in subjects taking amlodipine.