Side Effects of Cialis (Tadalafil)
The most common side effects of Cialis (tadalafil) include headache (occurring in up to 15% of patients), dyspepsia (indigestion) (up to 10%), back pain (up to 6%), myalgia (muscle aches) (up to 3%), nasal congestion (up to 3%), and flushing (up to 3%). 1
Common Side Effects
Tadalafil's side effect profile is well-documented in clinical trials and FDA labeling. The most frequently reported adverse events include:
- Headache: Occurs in 3-15% of patients depending on dosage 1
- Dyspepsia (indigestion): Affects 2.4-10% of patients 1
- Back pain: Reported in 2.4-6% of patients 1
- Myalgia (muscle aches): Occurs in 1.2-4% of patients 1
- Nasal congestion: Affects 2-3% of patients 1
- Flushing: Occurs in 1-3% of patients 1
- Pain in extremities: Reported in 1.4-3% of patients 1
Back pain and muscle aches typically occur 12-24 hours after dosing and generally resolve within 48 hours. These symptoms are usually mild to moderate in severity and often resolve without treatment 1.
Cardiovascular Considerations
Cialis, like other PDE5 inhibitors, has important cardiovascular considerations:
- Absolute contraindication: Cannot be used with nitrates due to risk of severe hypotension. If nitrates are needed in an emergency, they should not be given until at least 48 hours after tadalafil use 2, 1
- Blood pressure effects: May cause mild to moderate decreases in blood pressure 1
- Cardiovascular risk assessment: Patients should be assessed for cardiovascular risk before starting treatment 2
Less Common Side Effects
Less frequent adverse reactions (occurring in <2% of patients) include:
- Digestive system: Nausea, vomiting, dry mouth, gastroesophageal reflux disease, abdominal pain 1
- Nervous system: Dizziness (1%), insomnia, paresthesia, somnolence, vertigo 1
- Respiratory: Dyspnea (shortness of breath), epistaxis (nosebleeds), pharyngitis 1
- Skin: Pruritus (itching), rash, sweating 1
- Vision/hearing: Blurred vision, changes in color vision (rare, <0.1%), eye pain, swelling of eyelids 1
Serious Adverse Events
Though rare, serious adverse events can occur:
- Priapism: Erection lasting more than 4 hours requires immediate medical attention to prevent permanent damage 1
- Vision changes: Sudden decrease or loss of vision (rare) 1
- Hearing changes: Sudden decrease or loss of hearing, sometimes with tinnitus and dizziness (rare) 1
- Non-arteritic anterior ischemic optic neuropathy (NAION): Risk may be increased in patients with certain eye conditions 3
Special Populations
- Elderly patients: Patients over 65 years may experience more diarrhea (2.5% vs. younger patients) 1
- Patients with renal/hepatic impairment: May require dose adjustments; use with caution in severe cases 1
- Patients with diabetes: Tadalafil is effective but response may be less robust than in non-diabetic patients 2, 4
Precautions and Monitoring
- Regular follow-up is recommended to assess efficacy, side effects, and any changes in health status or medications 2
- Patients should report any chest pain, severe dizziness, or fainting immediately 1
- Avoid excessive alcohol consumption which can increase risk of headache, dizziness, increased heart rate, or lower blood pressure 1
Differences from Other PDE5 Inhibitors
Tadalafil has a longer half-life (17.5 hours) compared to other PDE5 inhibitors, allowing for once-daily dosing options and effectiveness up to 36 hours after taking the medication 1, 5.
Long-term safety studies have shown that tadalafil remains well-tolerated with continued use over periods of 18-24 months, with no new safety concerns emerging with extended use 6.