What Is Tadalafil and How Does It Work?

The primary use of tadalafil is to treat erectile dysfunction. Tadalafil is a PDE5 inhibitor.

As with other ED medicines, tadalafil’s effects last less than 24 hours. Research has shown that the half-life for tadalafil is about 17.5 hours, so the effects are present longer than for other PDE5 inhibitors.

Tadalafil can be used to treat BPH and address symptoms associated with an enlarged prostate. As mentioned above, tadalafil can be prescribed for the treatment of PAH, but only for the dosing and form ratio used in that specific case.

To treat BPH, Tadalafil work similarly to other alpha blockers and relaxes the prostate and the surrounding muscles. It also widens the urethra for easier urine flow.

How Does Tadalafil Work?

Tadalafil works by blocking the enzyme phosphodiesterase type 5 (PDE5).

During sexual stimulation, the body produces nitric oxide. This leads to an increase in another chemical, cyclic guanosine monophosphate (cGMP). cGMP is responsible for the relaxation of smooth muscles lining the blood vessels of the penis. This then enables blood flow and the formation of an erection.

PDE5 serves to degrade cGMP. By limiting PDE5, tadalafil allows cGMP to persist and therefore serves to improve the erection by increasing blood flow.

It is essential to note that tadalafil will not cause an automatic erection. Sexual stimulation is still necessary for the medicine to function.

What Is Tadalafil Used For?

Tadalafil has many different approved uses.

Erectile Dysfunction

For the treatment of erectile dysfunction (ED), the prescription of tadalafil helps enhance the ability for achieving and maintaining an erection during sexual intercourse. Results of clinical studies have documented improved scores for erectile function and successful completion of intercourse when compared to the placebo.

Benign Prostatic Hyperplasia

In the treatment of benign prostatic hyperplasia (BPH), tadalafil helps alleviate lower urinary tract symptoms such as difficulty initiating urination and urinating frequently.

Pulmonary Arterial Hypertension

Tadalafil in its formulated doses is indicated for the treatment of pulmonary arterial hypertension (PAH). Due to the nature of the condition, this use of tadalafil is different than the treatment of erectile dysfunction. Tadalafil for PAH requires ongoing medical supervision.

How Long Does Tadalafil Work?

One characteristic of tadalafil is its length of action.

Research shows improvement beyond 36 hours after use of tadalafil when dealing with proper patients to aid in the erectile function during that period.

This length of time is associated with tadalafil’s half-life of around 17.5 hours. In a study of 237 participants given a dose of 20 mg, the average time for participants to reach blood concentration levels took about 2 hours, and the average half-life was 17.5 hours.

The correct tadalafil dose is determined by why a patient is being prescribed the medication and their existing health conditions.

Tadalafil Dosage

The dose of tadalafil is determined based on the reason for use and the patient’s health.

For erectile dysfunction, tadalafil is prescribed in the following ways:

As needed: dose of 10 mg with a potential increase to 20 mg, and a decrease to 5 mg based on response and tolerance.

Most medical practitioners recommend starting doses of 2.5 mg or 5 mg to be taken once a day. The correct dose of tadalafil should be prescribed by your doctor. Avoid taking tadalafil more than instructed by your doctor.

Does Food Affect Tadalafil?

Food does not affect the absorption of tadalafil as it does other ED medicines (if at all). According to research, food has minimal effect on the bioavailability of tadalafil. Therefore, tadalafil can be taken with or without food, as directed on the prescription.

However, tadalafil should be avoided with excessive alcohol as the risk of dizziness and low blood pressure are increased. The NHS also advises against the consumption of grapefruit juice when tadalafil is taken as it may affect how the medicine functions.

Common Side Effects of Tadalafil

Most people do not suffer from any side effects of tadalafil. The common side effects of tadalafil include:

• Headaches
• Indigestion
• Back pain
• Muscle pain
• Flushing
• Stuffy or blocked nose

These side effects are mild, but anyone who experiences any persistent or troublesome symptoms should contact their healthcare professional.

Who Should Not Take Tadalafil?

Tadalafil is not suitable for everyone. One of the most important considerations is that tadalafil should not be taken in conjunction with any nitrate medicines as these are used to control chest pain.

Combination of tadalafil and nitrates has been shown to cause a potentially hazardous drop in blood pressure. The American Urological Association does not recommend that men on nitrates use PDE5 inhibitors.

Tadalafil should be used with caution in men with certain heart, kidney, liver or blood pressure conditions.

Tadalafil and Other Drugs

Some of the medicines that tadalafil can potentially interact with include:

• Nitrates
• Blood Pressure Lowering Drugs
• Alpha Blockers
• Certain Antifungals
• Certain Antibiotics
• Certain HIV Medicines
• Other Erectile Dysfunction Medicines

Tadalafil should not be used in combination with another PDE5 inhibitor unless a health care professional advises otherwise.

What Does the Research Say About Tadalafil?

Tadalafil has been well-studied in men with erectile dysfunction. One study integrated data for 1,112 men across five randomized, placebo-controlled trials; tadalafil was shown to be effective in improving erectile dysfunction metrics. In the 20 mg group, 75% of attempts at intercourse were successful, while intercourse attempts in the placebo group resulted in significant lower metrics for success.

Improvements in the metrics for erectile dysfunction using once-daily tadalafil has also been studied. In a study involving 1,913 men from randomized clinical studies, the daily tadalafil group improved outcomes for intercourse with greater success compared to the placebo group.

Frequently Asked Questions

Does tadalafil improve sexual desire?

Tadalafil does not change sexual desire. Tadalafil increases blood flow and helps the physical process of becoming aroused.

Does tadalafil work without sexual stimulation?

Tadalafil does not work in the absence of sexual stimulation.

How quickly does tadalafil start working?

Tadalafil can start helping some men in about 30 minutes, but the response time can vary. Unlike other medications with a shorter duration, tadalafil does not have to be taken immediately before sexual activity.

Is tadalafil the same as Viagra?

No, Viagra has sildenafil, and tadalafil is a different PDE5 inhibitor. Both medications enhance the process of achieving an erection by increasing the availability of cGMP, but tadalafil has a much longer duration than sildenafil.

Conclusion

Tadalafil is a PDE5 inhibitor that has been thoroughly researched for the treatment of erectile dysfunction. It also has uses for benign prostatic hyperplasia (BPH) and pulmonary arterial hypertension. Tadalafil works by inhibiting PDE5 and prevents the breakdown of cyclic guanosine monophosphate (cGMP). As a result, cGMP levels increase and promote the relaxation of penile blood vessels in order for blood to flow into the penis during sexual stimulation.

Due to its half-life of about 17.5 hours, the therapeutic window for tadalafil is longer than most other ED medications. Erectile dysfunction treatments are often administered once to allow benefits to last for 36 hours.

Medical advice should always be sought out and tadalafil should be used with caution if you have cardiovascular, renal, hepatic, or are on nitrate medication.

Sources

• NHS – Tadalafil: current patient information, uses, dosing, interactions, and side effects.
• PubMed – Tadalafil pharmacokinetics in healthy subjects: pharmacokinetic analysis of 237 subjects and the 17.5-hour mean half-life.
• American Urological Association – Erectile Dysfunction Guideline: PDE5 inhibitor mechanism and safety considerations.
• PubMed – Integrated tadalafil efficacy analysis: clinical trial data from 1,112 men.
• PubMed – Once-daily tadalafil: integrated analysis of 1,913 patients.