Tadalafil

Tadalafil Clinical Information

How Tadalafil Works

Tadalafil is a phosphodiesterase type-5 (PDE5) inhibitor — the same class as sildenafil — but with a much longer duration of action (up to 36 hours, sometimes longer). It enhances the body’s natural erectile response when sexual stimulation triggers nitric oxide release. Tadalafil does not cause an erection on its own; sexual stimulation is required. It can be dosed two ways: as-needed before activity, or daily at a low dose for spontaneous responsiveness.

Indications

• Erectile dysfunction (ED) in adult men
• Symptoms of benign prostatic hyperplasia (BPH) — daily dosing
• Pulmonary arterial hypertension (PAH) — different brand, different dose, not addressed here

Do Not Use If You Take Nitrates

Combining tadalafil with any nitrate medication can cause a sudden, life-threatening drop in blood pressure. Tadalafil’s long half-life means the interaction risk persists for at least 48 hours after the last dose. Nitrates include:

• Nitroglycerin (sublingual tablets, sprays, patches, ointment, IV)
• Isosorbide mononitrate (Imdur, Monoket)
• Isosorbide dinitrate (Isordil, Dilatrate-SR)
• Amyl nitrate / amyl nitrite (“poppers”)

Tell your provider before starting any PDE5 inhibitor if you have ever been prescribed a nitrate.

Other Contraindications

• Riociguat (Adempas) or other guanylate cyclase stimulators
• Recent heart attack or stroke (within 6 months)
• Unstable angina or severe heart failure
• Severely uncontrolled high or low blood pressure
• Severe liver impairment
• Hereditary degenerative retinal disorder
• Known allergy to tadalafil

Use with Caution If You Have

• Cardiovascular disease where sexual activity is inadvisable
• History of priapism or penile anatomical issues
• Sickle cell anemia, multiple myeloma, or leukemia
• Bleeding disorders or active peptic ulcer
• Hearing impairment

Drug Interactions

• Alpha-blockers (tamsulosin/Flomax, doxazosin, terazosin)
• Other antihypertensive medications
• HIV protease inhibitors (ritonavir, indinavir)
• Strong CYP3A4 inhibitors: ketoconazole, itraconazole, clarithromycin, erythromycin
• Recreational substances (especially “poppers”; see contraindications)

Common Side Effects

• Headache
• Back pain (more common than with sildenafil)
• Muscle aches
• Indigestion
• Stuffy nose
• Facial flushing
• Dizziness

When to Seek Emergency Care

Call 911 or go to the nearest emergency room if you experience:

• Erection lasting more than 4 hours (priapism) — immediate intervention required
• Sudden vision loss in one or both eyes
• Sudden hearing loss
• Severe chest pain, shortness of breath, or fainting during or after use

Tadalafil Dosing Strategies

• As-needed — taken 30–60 minutes before sexual activity. Effects last 24–36+ hours, giving more spontaneity than shorter-acting options.
• Daily low-dose (2.5–5 mg) — for men who want continuous responsiveness without timing doses to activity. Also treats BPH symptoms.

How DMHealth Prescribes Tadalafil

1. Free virtual consultation and goals discussion
2. Cardiovascular & medication screen — confirm no nitrate use or other contraindications
3. Provider evaluation by Diana Medina, MMS, PA-C, under Luis Campillo, MD’s medical direction
4. Compounded prescription via verified pharmacy when appropriate
5. Dosing strategy chosen with you — as-needed vs. daily
6. Follow-up for response, side effects, and any dose changes