The recommended dosage of Fildena CT 100 is typically one tablet taken orally, chewed, and swallowed approximately 30 minutes to 1 hour before anticipated sexual activity. It is important to follow your healthcare provider's instructions regarding dosage and usage for safe and effective treatment of ED. Fildena CT 100 is generally well-tolerated when used as directed. However, like any medication, it may cause side effects in some individuals. Common side effects of sildenafil citrate may include headache, flushing, nasal congestion, upset stomach, back pain, and muscle aches. These side effects are usually mild and temporary.