Comparison of Drugs for Male Erectile Dysfunction: Tadalafil, Sildenafil & Apomorphine Hydrochloride Sublingual Tablets

Drug Name	Drug Type	Mechanism of Action	Indications	Dosage and Administration	Common Side Effects	Contraindications	Special Population Precautions
	Apomorphine Hydrochloride Sublingual Tablets	Sildenafil	Tadalafil
Drug Type	Dopamine D2 receptor agonist	Phosphodiesterase type 5 (PDE5) inhibitor	Phosphodiesterase type 5 (PDE5) inhibitor
Mechanism of Action	Stimulates dopamine receptors in the central nervous system to improve erectile function	Inhibits PDE5 enzyme, enhances nitric oxide (NO) effects, relaxes vascular smooth muscle, increases genital blood flow	Inhibits PDE5 enzyme, enhances nitric oxide (NO) effects, relaxes vascular smooth muscle, increases genital blood flow with longer duration of action
Indications	Male erectile dysfunction	Male erectile dysfunction	Male erectile dysfunction; Erectile dysfunction with benign prostatic hyperplasia
Dosage and Administration	Sublingual administration 20 minutes before sexual activity, starting dose 2mg, adjustable to 3mg or 4mg	Oral administration 0.5-4 hours before sexual activity, recommended starting dose 50mg, adjustable to 25mg or 100mg	On-demand use: recommended starting dose 10mg, adjustable to 20mg or 5mg; Once-daily use: recommended starting dose 2.5mg, adjustable to 5mg
Common Side Effects	Nausea, headache, dizziness, drowsiness, occasional syncope	Headache, facial flushing, nasal congestion, indigestion, rare sudden hearing loss and NAION	Headache, indigestion, less common eyelid swelling or eye pain and conjunctival hyperemia
Contraindications	Hypersensitivity to apomorphine, severe cardiovascular disease, hypotension, etc.	Hypersensitivity to sildenafil, recent heart attack, severe hepatic/renal impairment, hypotension, concurrent use with nitrates	Hypersensitivity to tadalafil, patients taking nitrate medications
Special Population Precautions	No dose adjustment required for elderly patients	Dose adjustment or contraindication for severe hepatic/renal impairment	Caution in mild-moderate hepatic impairment, contraindication in severe hepatic impairment; no dose adjustment needed for elderly patients

Purchase Recommendations:

1. Apomorphine Hydrochloride Sublingual Tablets

• Recommended For:
  • Patients requiring rapid improvement in erectile function (onset within ~15 minutes);
  • Individuals prioritizing discreet administration (sublingual route, no water needed);
  • Mild-to-moderate erectile dysfunction without severe cardiovascular comorbidities.
• Use With Caution/Contraindicated In:
  • Hypersensitivity to apomorphine;
  • Severe cardiovascular conditions (e.g., angina, hypotension), renal/hepatic impairment;
  • Concurrent use of dopamine antagonists or antihypertensives.

2. Sildenafil

• Recommended For:
  • Routine on-demand treatment for erectile dysfunction;
  • Stable cardiovascular patients with controlled comorbidities (medical evaluation required);
  • Those not requiring prolonged efficacy (4-6 hours duration).
• Use With Caution/Contraindicated In:
  • History of myocardial infarction, stroke, or severe arrhythmia within 6 months;
  • Concomitant nitrate therapy (e.g., nitroglycerin) or α-blocker use;
  • Retinitis pigmentosa or other retinal disorders.

3. Tadalafil

• Recommended For:
  • Patients desiring extended efficacy (up to 36 hours);
  • Individuals with comorbid benign prostatic hyperplasia and erectile dysfunction;
  • Those preferring fewer dietary restrictions (may be taken with food).
• Use With Caution/Contraindicated In:
  • Pediatric patients under 18 years or females;
  • Severe renal/hepatic impairment (dose adjustment required);
  • Concurrent strong CYP3A4 inhibitors (e.g., rifampin) or nitrate therapy.

Universal Recommendations:

1. Complete cardiovascular risk assessment prior to use (especially for patients with hypertension, diabetes, etc.);
2. Avoid concurrent PDE5 inhibitor therapy to prevent hypotensive risks;
3. Discontinue use and seek immediate medical attention for chest pain, visual disturbances, or other adverse reactions.