Cialis Side Effects: A Comprehensive Guide

Before you start taking any prescription medication, it’s important to learn about the potential risks and side effects involved — erectile dysfunction treatments like Cialis are no different. Here, the ZipHealth clinical experts break down everything you need to know to guide you through this popular treatment, the risks, and how to take it safely.

How does Cialis (tadalafil) treat erectile dysfunction?

Cialis is a branded erectile dysfunction, sometimes sold in a smaller daily dose, known as Cialis Daily. The active ingredient in Cialis is tadalafil, a type of medication called phosphodiesterase type 5 inhibitors (PDE5 inhibitors. It helps to treat erectile dysfunction by relaxing the blood vessels in the penis, allowing more blood to flow during sexual stimulation or arousal. With more blood filling the penis, it’s easier to both achieve and maintain erections.

What are the common side effects of Cialis?

There are some common side effects of Cialis, but the good news is they’re temporary, and often don’t last very long. Before we take a look, here are some important points to remember.

1. Keep your patient information leaflet handy: Always keep the information that comes with your medication, as it can be an important reference for side effects.
2. Your prescription is personal: Cialis (tadalafil) is prescribed specifically for you, so follow your prescriber’s instructions on how to take it. Don’t share it with others, even if they have similar symptoms — it could harm them.
3. Report side effects: If you experience any side effects, inform your doctor or pharmacist immediately, even if they aren’t listed here.

Potential Side Effects

Common Side Effects (May affect up to 1 in 10 people)

Headaches

Clinical studies indicate that up to 15 percent of people experience headaches with Cialis (tadalafil), and that they’re more likely at higher doses [1]. Here’s how we recommend combating them:

• Over-the-counter pain relief: Common pain relievers like aspirin or acetaminophen can help manage headache pain.
• Taking a lower dose: Because studies show that side effects are more prevalent at higher doses [1], it may help to reduce your dose. Speak to your prescriber about lowering your dose, or consider Cialis Daily (or tadalafil 2.5mg) instead of taking a stronger dose before sexual activity.

Indigestion

If you experience indigestion after taking Cialis, don’t worry — it’s so common that it’s even been dubbed ‘Cialis heartburn’, and it’s easy to treat with over-the-counter antacids. Stomach problems like indigestion are the second most common side effect of tadalafil (the active ingredient in Cialis), with 8-10% of users reporting it. It's not just Cialis that can trigger this — all PDE5 inhibitors are associated with this side effect.

That's because as well as relaxing your blood vessels, PDE5 inhibitors can also relax the 'lower esophageal sphincter' (LES). The LES is a collection of muscle fibres that stop food moving back up the food pipe after eating. When relaxed, it can lead to heartburn and other stomach upsets as stomach acid travels back up the food pipe.

If you're already taking steps to prevent indigestion, acid reflux, upset stomach, and heartburn (including drinking more water and taking antacids), speak to your prescriber or healthcare provider for more advice.

Nasal congestion

Some people report a stuffy nose when taking Cialis. [1] This might occur because the drug  improves your blood flow by relaxing the muscles that line your blood vessels. Relaxing these muscles dilates your blood vessels, lowering your nitric oxide levels. Nitric oxide promotes healthy breathing, and reducing it slightly can lead to nasal congestion, or make it more difficult to breathe comfortably.

Like other side effects, nasal congestion normally subsides once the medication is no longer in your system. As Cialis (tadalafil) can work for up to 36 hours, anyone affected by this particular symptom may prefer to try PDE5 inhibitors with a shorter half life, such as Viagra (sildenafil), which lasts an average of 1-4 hours.

Flushing

Facial flushing is another possible side effect of Cialis. Like other side effects we've covered so far, this is also caused by the active ingredient, tadalafil, improving blood flow throughout the body. This can lead to dilated blood vessels in the face, which might lead to a temporarily flushed appearance, particularly around the nose, cheeks, chin, and forehead.

Approximately three percent of people who use Cialis experience this side effect, and it tends to occur more in higher doses. It's unlikely that switching to a different PDE5 inhibitor erectile dysfunction treatment will reduce the chances of facial flushing — it should simply fade as the medication leaves your body.

Muscle or back pain

One lesser known, but relatively common, side effect is myalgia, which includes pain in the muscles, ligaments, tendons, and fascia (connective tissues). It affects a small percentage of men using Cialis (tadalafil) — up to 5% experience muscle pain, and 6% experience back pain, according to clinical trials. (1)It typically appears 12-24 hours after taking the medication, but normally resolves within 24 hours, before the medication has lost its effects. If this side effect causes you discomfort while using an ED treatment, over-the-counter pain relievers like acetaminophen can help until the pain subsides.

Other side effects of Cialis (tadalafil)

There are, of course, more adverse effects than can occur while taking Cialis, but they’re much less common. Here’s a look at these potential symptoms, at a glance:

Uncommon side effects (May affect up to 1 in 100 people):

• Dizziness
• Stomach upset such as aching, nausea, or vomiting
• Blurred vision, eye pain
• Difficulty breathing
• Blood in urine
• Prolonged erections
• Rapid or pounding heartbeat
• Low or high blood pressure
• Nose bleeds
• Ringing in the ears
• Swelling of the hands, feet, or ankles
• Fatigue

Rare side effects (May affect up to 1 in 1,000 people):

• Fainting
• Seizures, memory loss
• Swelling of the eyelids, red eyes
• Sudden hearing loss
• Hives
• Penile bleeding, blood in semen
• Increased sweating
• Heart attack or stroke (rarely, usually in men with pre-existing heart problems)
• Vision loss in one or both eyes

When to seek emergency medical care for Cialis (tadalafil) side effects

If, at any time, you experience an allergic reaction, including rashes, you should seek emergency medical attention by calling 911 or visiting your nearest ER department.You should also get urgent medical attention if you experience chest pain, sudden vision or hearing loss, or priapism (which is an erection lasting more than 4 hours).

Who should not use Cialis (tadalafil)?

Although Cialis is a regulated medication approved by the FDA and widely trusted by medical professionals, it's not suitable for all men. If you're allergic to tadalafil or any other ingredients in the medication, or have had allergic reactions to PDE5 inhibitors before, you shouldn't attempt to take Cialis for erectile dysfunction. Instead, speak to your primary healthcare provider for advice.

• Are taking nitrates or nitric oxide donors (e.g., amyl nitrite), often used for chest pain, as it can increase their effects.
• Have serious heart conditions or have had a recent heart attack or stroke.
• Have low or uncontrolled high blood pressure.
• Have experienced vision loss due to Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION).
• Are taking riociguat, a medication for pulmonary arterial hypertension.
• Are using recreational drugs, as this can cause a serious health risk.

Other important precautions:

Sexual activity can pose risks for those with heart disease, so consult your primary care provider before taking ED medication if you have heart problems.

Interaction with Cialis (tadalafil) and other medicines

Always inform your doctor about any other medications you are taking. Tadalafil can interact with several drugs, including:

• Alpha blockers (for high blood pressure or prostate issues)
• Other blood pressure medications
• Riociguat
• 5-alpha reductase inhibitors (for prostate issues)
• Antifungal medications like ketoconazole or itraconazole
• HIV medications (protease inhibitors)
• Anticonvulsants like phenobarbital, phenytoin, and carbamazepine

You should also speak to your doctor about the risks of erectile dysfunction treatments if you have any other health issues such as sickle cell anaemia, multiple myeloma, leukaemia, penile deformities, liver, or kidney problems.

Looking to start an erectile dysfunction medication like Cialis or tadalafil? Find the right treatment for you with our fast, free online consultation at ZipHealth now.

References

1. Coward RM, Carson CC. Tadalafil in the treatment of erectile dysfunction. Therapeutics and Clinical Risk Management [Internet]. 2008 Dec 1;4(6):1315–30. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2643112/