What are the side effects of Cialis (tadalafil)?

Side Effects of Cialis (Tadalafil)

Cialis (tadalafil) commonly causes headache, dyspepsia (indigestion), back pain, muscle aches, flushing, and nasal congestion as its primary side effects, with most resolving within a few hours after taking the medication. 1

Common Side Effects

The FDA-approved drug label for tadalafil reports the following common side effects with their frequency rates:

• Headache: 3-15% (dose-dependent)
• Dyspepsia (indigestion): 2.4-10% (dose-dependent)
• Back pain: 2.4-6% (dose-dependent)
• Myalgia (muscle aches): 1.2-4% (dose-dependent)
• Nasal congestion: 2-4%
• Flushing: 1-3%
• Pain in extremities: 1.4-3%
• Dizziness: 1%

Most of these side effects are mild to moderate in severity and typically resolve on their own within a few hours 1.

Timing and Characteristics of Back Pain/Myalgia

Back pain and muscle aches associated with tadalafil:

• Usually occur 12-24 hours after dosing
• Typically resolve within 48 hours
• Are characterized by diffuse bilateral lower lumbar, gluteal, thigh, or thoracolumbar muscular discomfort
• Are exacerbated by lying down
• Generally mild to moderate in severity (severe back pain occurs in less than 5% of cases)
• Usually resolve without medical treatment 1

Serious Side Effects

Although rare, tadalafil can cause serious side effects that require immediate medical attention:

1. Priapism: An erection lasting more than 4 hours requires immediate medical attention to prevent permanent damage to the penis 1

2. Vision changes: Rare cases of sudden vision decrease or loss, sometimes with color vision changes (blue tinge to objects or difficulty distinguishing blue from green) 1

3. Hearing loss: Sudden decrease or loss of hearing, sometimes with tinnitus and dizziness 1

4. Cardiovascular effects: Patients with cardiac conditions may experience adverse cardiovascular events 2

Cardiovascular Considerations

Tadalafil is contraindicated in patients:

• Taking nitrates in any form
• With unstable angina or recent cardiovascular events
• With uncontrolled hypertension 2

The American Heart Association recommends a waiting period of 48 hours between taking tadalafil and nitrate administration in case of a medical emergency 2.

Less Common Side Effects (<2%)

Additional less frequent side effects include:

• Digestive: dry mouth, nausea, vomiting, GERD, abdominal pain
• Musculoskeletal: arthralgia, neck pain
• Nervous system: insomnia, paresthesia, somnolence, vertigo
• Respiratory: dyspnea, epistaxis, pharyngitis
• Skin: pruritus, rash, sweating
• Ophthalmologic: blurred vision, conjunctivitis, eye pain, increased lacrimation
• Urogenital: spontaneous penile erection 1

Risk Factors for Increased Side Effects

Certain populations may experience more pronounced side effects:

• Elderly patients (>65 years): Higher incidence of diarrhea (2.5%)
• Patients with hepatic or renal impairment: May experience delayed metabolism
• Patients taking certain medications: Potential drug interactions 1

Minimizing Side Effects

To minimize side effects:

• Start with the lowest effective dose
• Take as directed (with or without food)
• Avoid excessive alcohol consumption, which can increase dizziness and lower blood pressure
• Do not use other ED treatments simultaneously
• Report persistent or bothersome side effects to your healthcare provider 1

Long-term Safety

Long-term studies have shown that tadalafil maintains a consistent safety profile over extended use, with no new or unexpected adverse events emerging with continued treatment 3. The discontinuation rate due to adverse events in long-term studies was approximately 6.3%, with no single adverse event causing discontinuation in more than 1% of patients 3.