Minipress and Revatio Injection

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Talk to your doctor before using sildenafil together with prazosin. Combining these medications can lower your blood pressure and increase the risk of dizziness, lightheadedness, fainting, flushing, headache, and nasal congestion. These side effects may also occur with either medication alone and are most likely to be seen at the beginning of treatment, following a dose increase, or when treatment is restarted after an interruption. Let your doctor know if you develop these symptoms and they do not go away after a few days or they become troublesome. Avoid driving or operating hazardous machinery until you know how these medications affect you, and use caution when getting up from a sitting or lying position. In general, your blood pressure should be stable and you should be on a steady dose of one medication before you begin the other. You may need a dose adjustment or your blood pressure checked more often if you take both medications. 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.

ADJUST DOSE: Sildenafil may potentiate the hypotensive effect of alpha blockers, resulting in symptomatic hypotension in some patients. Sildenafil 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 patients with benign prostatic hyperplasia stabilized on the alpha blocker doxazosin, coadministration of doxazosin (4 mg or 8 mg) and sildenafil (25 mg, 50 mg, or 100 mg) resulted in mean additional reductions of supine systolic and diastolic blood pressure of 7/7 mmHg, 9/5 mmHg, and 8/4 mmHg, respectively. Mean additional reductions of standing blood pressure of 6/6 mmHg, 11/4 mmHg, and 4/5 mmHg, respectively, were also observed. There were infrequent reports of patients experiencing symptomatic postural hypotension (dizziness, lightheadedness) 1 to 4 hours after dosing with doxazosin 50 or 100 mg. In a clinical study of healthy male subjects 45 to 78 years of age, administration of silodosin with a single 100 mg dose of sildenafil 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 sildenafil.

MANAGEMENT: Caution is advised if sildenafil 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 sildenafil. Therefore, patients should be stable on alpha blocker therapy prior to initiating sildenafil, and sildenafil should be initiated at the lowest recommended dosage when used for erectile dysfunction (i.e., 25 mg). No dosage adjustment is necessary if used in the treatment of pulmonary arterial hypertension. In those patients already on an optimized dosage of sildenafil, alpha blocker therapy should be initiated at the lowest dosage. The safety of sildenafil in combination with alpha blockers may be affected by other variables such as intravascular volume depletion and use of other antihypertensive medications.

Minipress

Generic Name: prazosin

Brand name: Minipress

Synonyms: n.a.

What is Minipress?

Revatio Injection

Generic Name: sildenafil

Brand name: Revatio, Viagra

Synonyms: Revatio

What is Revatio Injection?