What is Tadalafil?
Tadalafil is a prescription medication belonging to a class of drugs called
phosphodiesterase type 5 (PDE5) inhibitors. It was approved by the FDA in 2003 and is
marketed under the brand names Cialis (for erectile dysfunction and
benign prostatic hyperplasia) and Adcirca (for pulmonary arterial
hypertension).
Key Facts
- Generic Name: Tadalafil
- Brand Names: Cialis, Adcirca
- Drug Class: PDE5 Inhibitor
- FDA Approval: 2003
- Duration: Up to 36 hours
Uses
Tadalafil is FDA-approved for several conditions:
1. Erectile Dysfunction (ED)
The primary use of Tadalafil is to treat erectile dysfunction in men. It helps achieve
and maintain an erection sufficient for sexual activity when sexually stimulated.
2. Benign Prostatic Hyperplasia (BPH)
Tadalafil is also approved to treat symptoms of an enlarged prostate, including
difficulty urinating, weak stream, and frequent urination.
3. ED and BPH Combined
Tadalafil can be prescribed to treat both conditions simultaneously.
4. Pulmonary Arterial Hypertension (PAH)
Under the brand name Adcirca, Tadalafil is used to treat pulmonary arterial hypertension
to improve exercise capacity.
How It Works
Tadalafil works by inhibiting the enzyme phosphodiesterase type 5 (PDE5). Here's how the
process works:
- Sexual Stimulation: When sexually
aroused, your body releases nitric oxide.
- Increased cGMP: Nitric oxide
triggers the production of cyclic guanosine monophosphate (cGMP).
- Muscle Relaxation: cGMP relaxes
smooth muscle tissue and dilates blood vessels.
- Increased Blood Flow: This allows
increased blood flow to the penis.
- PDE5 Inhibition: Tadalafil prevents
PDE5 from breaking down cGMP, maintaining the erection.
âšī¸
Important: Tadalafil only works in the presence of sexual
stimulation. It does not cause automatic erections or increase sexual desire.
Onset and Duration
- Onset Time: Typically begins working within 30-60 minutes
- Peak Effect: Reaches maximum concentration in 2 hours
- Duration: Can remain effective for up to 36 hours
- Food Interaction: Can be taken with or without food
Dosage Information
| Condition |
Dosing Schedule |
Typical Doses |
| ED (As-Needed) |
Take before sexual activity |
5mg, 10mg, or 20mg |
| ED (Daily) |
Once daily, same time |
2.5mg or 5mg |
| BPH |
Once daily |
5mg |
| ED + BPH |
Once daily |
5mg |
| PAH |
Once daily |
40mg (Adcirca) |
Important Dosage Guidelines
- Do not take more than one dose per day
- For as-needed use, take at least 30 minutes before sexual activity
- Daily dosing provides the flexibility for spontaneous sexual activity
- Your doctor may adjust your dose based on effectiveness and tolerability
- Lower doses may be recommended for those with kidney or liver problems
â ī¸
Warning: Never exceed the prescribed dose. Taking more than
recommended does not improve effectiveness and increases the risk of serious side
effects.
Side Effects
Common Side Effects
These side effects are generally mild and may decrease over time:
- Headache
- Indigestion or heartburn
- Back pain
- Muscle aches
- Flushing (warmth, redness)
- Stuffy or runny nose
Serious Side Effects
Seek immediate medical attention if you experience:
đ¨
Seek Emergency Care:
- Erection lasting more than 4 hours (priapism)
- Sudden vision loss in one or both eyes
- Sudden hearing decrease or loss
- Chest pain or irregular heartbeat
- Severe dizziness or fainting
- Shortness of breath
Warnings & Precautions
Do Not Take Tadalafil If:
đĢ
- You take nitrates for chest pain (nitroglycerin, isosorbide)
- You take riociguat (Adempas) for pulmonary hypertension
- You are allergic to tadalafil or any ingredients
- Your doctor has advised against sexual activity
Tell Your Doctor If You Have:
- Heart problems or history of heart attack/stroke
- High or low blood pressure
- Liver or kidney disease
- Blood cell disorders (sickle cell anemia, leukemia)
- Bleeding disorders
- Stomach ulcers
- Peyronie's disease or penile deformity
- Retinitis pigmentosa or vision problems
Drug Interactions
Tadalafil can interact with many medications. Always inform your healthcare provider
about all medications you're taking, including:
- Alpha-blockers for prostate or blood pressure
- Other blood pressure medications
- Antifungal medications (ketoconazole, itraconazole)
- Antibiotics (clarithromycin, erythromycin)
- HIV protease inhibitors
- Other ED medications