Sildenafil for Pulmonary Hypertension

What is Sildenafil or Sildenafil Citrate? 

Sildenafil is a potent and selective inhibitor of cGMP-specific phosphodiesterase type 5 (PDE5). 

It is associated with the treatments of Erectile Dysfunction (ED) or impotency in men, hypertension or NYHA Functional Class II-III Pulmonary arterial hypertension (PAH), and Premature Ejaculation (PE). 

Is Sildenafil used to treat Pulmonary Hypertension?

The US Food and Drug Administration (FDA) has given full approval of using sildenafil to treat pulmonary hypertension in adults. However, it slightly differs in the case of children. The FDA doesn’t recommend ‘never’ giving the drug to children. Instead, it may be used when the benefits outweigh the risks and there are limited alternatives for treatment.

How does Sildenafil work for Pulmonary Hypertension?

Pulmonary hypertension causes vasoconstriction, where the blood vessels that supply blood to your lungs become tight and narrow. This increases the resistance against blood flow; which again is responsible for high blood pressure.

Sildenafil is a phosphodiesterase-5 (PDE5) inhibitor, meaning it decreases the activity of PDE5; thereby causing vasodilation or widening of your blood vessels. 

PDE5 is an enzyme that breaks down cyclic guanosine monophosphate (GMP). Cyclic GMP has a relaxing effect on your blood vessels.

Sildenafil lowers your PDE5 levels; which allows more cyclic GMP to act on the blood vessels. This results in vasodilation, which lowers resistance against blood flow and lowers blood pressure.

What is the ideal dose of Sildenafil for Pulmonary Hypertension?

The usual sildenafil dosage for pulmonary hypertension is 5 mg or 20 mg; to be taken three times a day. A gap of  4 to 6 hours should be there between each of the doses. 

The ideal dosage depends on the severity of your PH. Therefore, you might need higher and more frequent doses if you have severe PH.

However, one should always consult a doctor first before taking such medications. 

Side effects of Sildenafil for Pulmonary Hypertension

Usually, not much is heard about Sildenafil for high blood pressure or even pulmonary hypertension (PH), inciting issues in patients. However, as with all medications, it might cause a few side effects as mentioned below:

• Stomach upset 
• Nausea
• Heartburn
• Headache
• Nosebleeds
• Skin flushing
• Trouble sleeping
• Shortness of breath
• Nasal congestion
• Low blood pressure
• Diarrhea
• Pain in the arms or legs
• Muscle aches
• Fever
• Numbness
• Fluid retention

In some rare cases, the following side effects may also occur: 

• A prolonged erection (lasting longer than 4 hours) in people with penises
• Sudden loss of vision in one or both eyes
• Sudden loss of hearing
• Allergic reactions to Sildenafil 

Precautions while taking Sildenafil for Pulmonary Hypertension

It’s recommended to avoid taking sildenafil if you:

• Have low blood pressure
• Are taking drugs that lower blood pressure, such as nitrates
• Are taking other medications that might interact with Sildenafil 
• Are taking antiretroviral agents for HIV or AIDS
• Are taking Viagra
• Have recently had a heart attack or stroke
• Have a serious heart or liver condition
• Have a condition that affects nerve function

Does sildenafil lower Pulmonary Hypertension in both men and women?

Yes, Sildenafil lowers pulmonary hypertension for both men and women and does not showcase any gender-specific side effects either.