What is Cialis (tadalafil) used for?

Cialis (Tadalafil): Uses and Clinical Applications

Cialis (tadalafil) is primarily used for the treatment of erectile dysfunction (ED), with additional approved uses for benign prostatic hyperplasia (BPH) symptoms and pulmonary arterial hypertension. 1

Primary Uses

Erectile Dysfunction Treatment

• Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor that increases blood flow to the penis by delaying cGMP degradation 2
• Mechanism: Produces smooth muscle relaxation in corpus cavernosum, enhancing blood flow resulting in erection during sexual stimulation 2
• Dosing options:
  • As-needed dosing: 10-20 mg taken prior to anticipated sexual activity 1
  • Daily dosing: 2.5-5 mg once daily for continuous treatment 3
• Daily use of tadalafil provides an alternative for couples who prefer spontaneous rather than scheduled sexual activity 2

Benign Prostatic Hyperplasia (BPH)

• Effectively treats lower urinary tract symptoms associated with BPH 4
• Can be particularly beneficial for men who have both ED and BPH symptoms 1
• Standard dose for BPH treatment is 5 mg daily 1

Pulmonary Arterial Hypertension

• Used at different doses for treatment of pulmonary arterial hypertension (PAH) 2
• Improves exercise capacity and delays clinical worsening in PAH patients 2

Clinical Efficacy

• In clinical trials, tadalafil significantly improved erectile function compared to placebo, with 64% of patients achieving normal erectile function scores 5
• Daily tadalafil (10/20 mg) has shown effectiveness as a salvage therapy for previous on-demand tadalafil non-responders 6
• Treatment satisfaction is high, with 87% of patients reporting satisfaction with tadalafil treatment 5
• Tadalafil's longer half-life (17.5 hours) allows for effectiveness up to 24-36 hours after dosing, distinguishing it from other PDE5 inhibitors 7

Important Contraindications and Precautions

• Absolute contraindication: Never use with nitrates due to risk of severe hypotension 1
  • Must wait at least 24 hours after taking tadalafil before using nitrates 3
• Do not use with guanylate cyclase stimulators like riociguat (Adempas®) 1
• Use with caution in patients with:
  • Recent cardiovascular events (MI within 90 days, unstable angina, stroke within 6 months) 1
  • Uncontrolled hypertension or hypotension 1
  • Heart failure (NYHA Class 2 or greater in last 6 months) 1

Side Effects and Monitoring

• Common side effects include headache, dyspepsia (indigestion), back pain, myalgia, nasal congestion, and flushing 3
• Rare but serious side effects requiring immediate medical attention:
  • Priapism (erection lasting >4 hours) 1
  • Sudden vision loss (possible NAION) 1
  • Sudden hearing decrease or loss 1

Unique Characteristics of Tadalafil

• Longer half-life (17.5 hours) compared to other PDE5 inhibitors 7
• Effective for up to 36 hours after dosing, earning it the nickname "weekend pill" 7
• No significant visual side effects reported, unlike some other PDE5 inhibitors 7
• Food and alcohol intake do not significantly affect its efficacy 1

Clinical Pearls

• For ED treatment, the recommended starting dose is typically 10 mg before sexual activity, which can be adjusted to 5 mg or 20 mg based on efficacy and tolerability 3
• The maximum recommended dosing frequency is once per day 1
• Daily dosing may be preferred for men who anticipate frequent sexual activity (>2 times weekly) 3
• Tadalafil has been shown to improve ejaculatory function and sexual satisfaction in addition to erectile function 4
• Consider tadalafil over tamsulosin for men with both BPH and ED, as tamsulosin may decrease ejaculatory/orgasmic frequency 4

Tadalafil represents an important treatment option with proven efficacy for erectile dysfunction, with additional benefits for those with comorbid BPH symptoms, offering flexibility in dosing regimens to accommodate patient preferences and lifestyle.