Interactions between Viagra and Estrogen in Treating Heart Failure?

We all know that Viagra is a drug created to eliminate the symptoms of impotence in men. But sildenafil (the main component of Viagra) can also be used to treat other diseases. That is, it can be used by women. Our article is devoted to the possible interactions of sildenafil and estrogen, which is contained in female drugs Estrace & Estrace Vaginal Cream.

Sildenafil as a Remedy for Patients with Heart Failure & PAH

Sildenafil citrate is a potent pharmaceutical agent that was originally developed to treat certain heart diseases. However, scientists found that the effect of the substance on the erection was higher. Therefore, they continued research in a new way, which resulted in the well-known blue pill. Now Viagra has a lot of competitors in the field of erectile dysfunction treatment. Therefore, developers and scientists are investigating old forgotten and new effects of sildenafil. For example, according to the study by Blum A. (2009), the substance improves the working capacity and quality of life of individuals suffering from heart failure.

In addition, sildenafil is widely used both by men & women for treating PAH (pulmonary arterial hypertension), the disease that can be caused by heart failure. The US FDA has approved the drug for using for such purpose. So in 2005, Pfizer company released a new medical remedy based on sildenafil and intended for improving symptoms of PAH. This drug is called Revatio the same as Generic Viagra. 

Estrace for Improving Symptoms of Menopause

Estrace is a medicament based on synthetic or natural (plant) analogues of estradiol, a female estrogen hormone. It is used to reduce the negative symptoms of the climacteric (menopause), such as hot flashes and a feeling of dryness inside the vagina. Such symptoms are caused by the fact that the body reduces the quantity of estrogens. If a woman uses Estrace only to treat the symptoms inside and around the vagina, it is better to choose the form of the drug for topical (intravaginal) administration, rather than oral tablets that have a more systemic effect. One of intravaginal forms is Estrace Vaginal Cream. It is prescribed for the treatment of dryness inside and around the vagina. The remedy is made from estrogen derived from plants.

How Might Sildanafil Interact with Estrogen (Estrace)?

It’s known that estrogen has natural protective effects for the heart. According to the study by Zoma WD (2004), sildenafil increases the amount of estrogen in blood current. However, the research by Dr. Takimoto (2014) has shown that estrogen negatively influences the effect of sildenafil in the treatment of heart failure in women, whereas in men such interaction has not been detected. Fortunately, sildenafil and estrogen combination doesn’t cause side effects. This suggests that doctors should take into account the patient’s sex when prescribing drugs.

Estrace (Estradiol) Drug Interactions

We have found out the possible interactions between sildenafil and estradiol. We believe that you should also be aware of other interactions of these medications. Estrace reduces the effect of diuretic medications, anticoagulants, antihypertensive, and anti-diabetic agents. It also reduces glucose tolerance. Therefore, a patient may need to adjust the regimen of taking medications intended to lower blood sugar levels. In addition, Estrace increases the effect of lipid-lowering agents. 

Some anticonvulsant and antimicrobial agents (including hydantoin anticonvulsants, barbiturate meds, primidone, carbamazepine, and rifampicin), can enhance the metabolism of estradiol. As a result, the effectiveness of the drug may be decreased. 

Supplements containing vitamin B9 (folic acid) and drugs for treating thyroid ailments strengthen the action of estradiol. Excess consumption of alcoholic beverages during the treatment with Estrace can lead to increased rates of circulating estradiol. This in turn can cause a number of adverse events, such as significant worsening of fertility, hyperthyroidism, and ovarian tumor (in rare cases).

Viagra (Sildenafil) Drug Interactions

If you take nitrates (drugs to treat certain heart diseases), you are not allowed to take generic sildenafil from Canada pharmacies. The combination of these medications can lead to a significant reduction in arterial pressure. Even lethal effect is possible. If you take a drug from the group of alpha-blockers to decrease high arterial pressure, it can also lead to a decrease in arterial pressure.

Care should be taken when using inhibitors of isoenzyme CYP3A4, such as erythromycin (antibiotic), ketoconazole (a medicine for fungal infections), itraconazole (another antifungal drug) simultaneously with sildenafil-based medical remedies.

How can these drugs interact? Isoenzyme CYP3A4 is responsible for the metabolism of external substances, including medicines. In the case of inhibition of this substance, the level of sildenafil in the blood current increases. This in some cases requires a dose adjustment.