Sildenafil Side Effects – Common and Uncommon effects of Viagra

Posted February 5, 2020 by Michael Chamberlain - See Editorial Guidelines

If you’re considering taking Sildenafil, or you’re already taking it and are perhaps experiencing unusual symptoms, then you may want to know what the list of Sildenafil side effects might be. In this article, we’re going to list all the common Sildenafil side effects.

But first, let’s make sure we all know what Sildenafil is, then we’ll head into the side effects and other information.

Sildenafil Side EffectsWhat Is Sildenafil? Sildenafil is a renowned prescription drug that is available in the form of a tablet and a liquid suspension, both of which are taken orally. It is also available in an intravenous (IV) form, but a licensed physician only administers this form.

The oral Sildenafil tablet is commercially available under brand-names Viagra and Revatio. It’s also available as a generic drug, which usually costs less for retail pricing compared to the brand-name variants of it.

Enrollment with Prescription Hope enables access to patient assistance programs, which can provide these brand name medications at a reduced cost.

Why Is Sildenafil Prescribed?

Sildenafil belongs to the family of drugs known as phosphodiesterase type 5 (PDE5) inhibitors. A family of drugs comprises of a group of medications that have a similar mechanism of action in the body.

These drugs are typically prescribed to treat a similar type of disorder.  Sildenafil works differently, though, depending upon the kind of condition it’s being used to treat.

  • For Erectile Dysfunction:

Sildenafil helps in increasing blood circulation towards the penis, which helps you either get or maintain an erection. Sildenafil will only work for this condition if one is already in a state of sexual arousal.

  • For Pulmonary Arterial Hypertension:

Sildenafil relaxes the smooth muscles and dilates the blood vessels in your lungs. This helps to reduce the blood pressure in your lungs. Sildenafil will slow down the rate of progression of your disease and enables you to perform vigorous exercises with greater ease.

How to Take Sildenafil Tablets

  • Take Sildenafil in the same manner as your healthcare practitioner advises you to take it.
  • Your healthcare practitioner will tell you how much Sildenafil to consume and at what time to take it.
  • Your healthcare practitioner should be the one to adjust your dose according to your needs. You should not increase or decrease the dose by yourself. 
  • Take Sildenafil about an hour before sexual intercourse. You may take Sildenafil between half an hour to four hours before sex if needed.
  • Sildenafil can be taken either with or without food. If you take the pill after a meal rich in fats, the medication will start exhibiting its effects immediately. 
  • Do not take Sildenafil more than once daily.
  • In case of an accidental overdose, call your doctor right away or visit the nearest healthcare facility as soon as possible. 

Before you take Sildenafil, inform your healthcare practitioner if you are, or have:

  • Previously suffered from any heart diseases or are currently facing any such as a heart attack, irregular heartbeat, chest pain, angina, narrowing of the atrial valve or heart failure
  • Have had cardiac surgery within the six months previous to taking the drug
  • Have pulmonary hypertension
  • Have suffered from a stroke
  • Have low blood pressure or high blood pressure that needs medication to be controlled
  • Have an unusual or deformed penis shape
  • Have experienced an erection that lasted for four or more hours
  • Have blood cell-related problems such as sickle cell anemia, multiple myeloma, or leukemia
  • Have retinitis pigmentosa, which is a rare eye disease running in families (of a genetic nature)
  • Have ever experienced loss of vision, including an eye disease known as non-arteritic anterior ischemic optic neuropathy (NAION)
  • Have bleeding issues
  • Have or experienced peptic ulcers
  • Have a liver disorder of any sort
  • Have a renal disease or are currently on kidney dialysis
  • Have a history of other disorders 

You should stop the intake of medication instantly if:

  • If you’re experiencing any erection that refuses to go away.
    Priapism is a medical condition in which an erection lasts for 4 hours or more than that. It is a grave condition that requires you to seek medical help right away. If it is not catered to right away, priapism can even result in causing permanent damage to your penis.
  • Sudden vision loss in one or both eyes. Sudden vision loss in either one or both the eyes can be a warning sign of a severe eye disorder known as non-arteritic anterior ischemic optic neuropathy (NAION). Stop taking Sildenafil and contact your healthcare practitioner immediately if you have experience vision loss in one or both your eyes.
  • Sudden decline in hearing ability or complete loss of hearing.
    Some people may experience a slight ringing in their ears, a condition known as tinnitus, or mild dizziness. If you expect such symptoms, then discontinue the use of Sildenafil and contact your physician right away.

Interactions of Various Drugs with Sildenafil

Sildenafil Side Effects

Before your healthcare practitioner prescribes you this medication, inform them of all the medicines you are currently taking, whether they are prescription, over-the-counter medications, vitamins, or any other nutritional and herbal supplements.

Sildenafil can affect how other medications might work, and other medications may interfere with the way Sildenafil works, causing serious side effects. You need to particularly inform your healthcare practitioner if you take any of the following medications:

  • Alpha-blockers, such as Uroxatral (alfuzosin), Cardura (doxazosin), Minipress (prazosin), Flomax, Jalyn (tamsulosin), and terazosin
  • Norvasc, Amturnide, Tekamlo (amlodipine)
  • Certain antifungals, such as Onmel, Sporanox (itraconazole) and Nizoral (ketoconazole)
  • Blood thinners, such as Coumadin, Jantoven (warfarin)
  • Certain barbiturates, such as Butapap, Fioricet, Fiorinal, other butalbital drugs and Seconal (secobarbital)
  • Beta-blockers, such as Tenormin, Tenoretic (atenolol), Trandate (labetalol), Lopressor, Toprol XL, Dutoprol (metoprolol), Corgard, Corzide (nadolol), and Hemangeol, Inderal LA, InnoPran (propranolol)
  • Tracleer (bosentan)
  • Cimetidine
  • Sustiva, Atripla (efavirenz)
  • E.E.S., E-Mycin, Erythrocin (erythromycin)
  • HIV protease inhibitors, including Reyataz, Evotaz (atazanavir), Prezista, Prezcobix (darunavir), Lexiva (fosamprenavir), Crixivan (indinavir), Kaletra (lopinavir), Viracept (nelfinavir), Norvir, Kaletra (ritonavir), Invirase (saquinavir), and Aptivus (tipranavir)
  • Viramune (nevirapine)
  • Other sorts of medications or therapies used to treat erectile dysfunction
  • Medicines for high blood pressure
  • Certain medicines for epilepsy and seizures, such as Carbatrol, Epitol, Tegretol, others (carbamazepine), phenobarbital, and Dilantin, Phenytek (phenytoin)
  • Mycobutin (rifabutin)
  • Rifadin, Rimactane, Rifamate, Rifater (rifampin)
  • Certain other antibiotics

Sildenafil Side Effects

Common Sildenafil Side Effects

The most commonly reported adverse reactions reported through clinical trials on human subjects include:

  • Headache
  • Flushing
  • Dyspepsia
  • Abnormal vision
  • Nasal congestion
  • Back pain
  • Myalgia
  • Nausea
  • Dizziness
  • Rash

Other Sildenafil Side Effects:

  • Cardiovascular side effects
  • Gastrointestinal side effects
  • Musculoskeletal side effects
  • Nervous system side effects
  • Ocular side effects
  • Respiratory side effects
  • Dermatologic side effects
  • Hematologic side effects
  • Metabolic side effects

Miscellaneous Sildenafil Side Effects

  • Psychological side effects
  • Genitourinary side effects
  • Hypersensitivity

Sildenafil and Alcohol 

Sildenafil is one of the most popular drugs for men who have erectile dysfunction. However, alcohol might be one of the primary reasons why you might have erectile dysfunction in the first place.

Alcohol might help you overcome your fears and anxiety and give you that boost of confidence. However, all of this comes at a price.

What happens is that alcohol consumption reduces the volume of blood that stays within your penis, which makes it difficult for you to get or maintain an erection.

If you’re taking Sildenafil because of your experience with erection problems in the past, then you should avoid consuming alcohol as much as possible.

In addition, alcohol and Sildenafil have been reported to interact. The drug is known to lower the blood pressure, and so does alcohol.

If your blood pressure level gets lower than normal, you’re bound to experience dizziness, light-headedness, fainting, severe headache, and even an irregular heartbeat. Undergoing such side effects isn’t only potentially harmful to your health; it also certainly doesn’t enhance your sexual performance.

Grapefruit and Sildenafil

Grapefruit and grapefruit juice are an overall healthy fruit and fruit beverage which provides an ample amount of vitamin C, potassium, dietary fiber, and other beneficial nutrients.

However, the bad news is that grapefruit juice can interact with a significant number of drugs, sometimes even in a dangerous manner.

Researchers have not been able to pinpoint which one of the hundreds of chemicals in grapefruit is mainly responsible for this. The leading suspect is the compound furanocoumarin, which is also found in sour oranges and tangelos. Thus, the precautionary guidelines for grapefruit also apply to these fruits, as well.

Why Do Grapefruit and Sildenafil Interact?

The suspected chemical in Grapefruit does not directly interact with Sildenafil. Instead, it acts in a way that binds to an enzyme in a person’s intestinal tract – an enzyme known as CYP3A4. This, in turn, decreases the absorption of this drug into the bloodstream, thus rendering the drug mostly ineffective.

In some, cases though, the chemicals in grapefruit juice can completely block the enzyme, this then makes it easier for the drug to pass from the digestive tract into the bloodstream.

This then causes blood levels to rise more rapidly than usual, and the abnormally high plasma levels of the blood can be potentially dangerous. This is a major Sildenafil side effect that requires urgent consultation with a physician.

To Conclude

We hope this has been useful in understanding the types of Sildenafil side effects you could be exposed to if you begin taking Sildenafil. Keep in mind that with any drugs, side effects can occur, but are less common than you might think.

As always, for a more in-depth consultation, refer to your relevant practitioner or your local doctor for further advice relating to your individual circumstances.

If you have any questions about how Prescription Hope can help you save money for any other drugs that we offer, or if you’re having trouble affording any of the medications you’ve been prescribed, then contact us. Visit the enrollment page to create an account and fill out an application and let us save you money!



ENROLL NOW LEARN MORE