Table 1. Adverse Effects Reported in > 2% of patients.8-10,16-18,20
| Adverse Effect by System | Sildenafil | Vardenafil | Tadalafil |
|---|---|---|---|
| Cardiovascular | Flushing | Flushing | Flushing |
| Central Nervous System | Headache, dizziness | Headache, dizziness | Headache |
| Gastrointestinal | Dyspepsia, diarrhea | Dyspepsia, nausea | Dyspepsia |
| Neuromuscular & Skeletal | N/A | Increased CPK | Increased CPK, back pain, myalgia |
| Respiratory | Nasal congestion | Rhinitis, sinusitis | Nasal congestion |
| Dermatologic | Rash | N/A | N/A |
| Ophthalmic | Abnormal vision (color changes, blurred or increased sensitivity to light) | N/A | N/A |
| Genitourinary | Urinary tract infection | N/A | N/A |
| Miscellaneous | N/A | Flu-like syndrome | Limb pain |
CPK = creatine phosphokinase