Tadalafil

Benjamin Clanner-Engelshofen is a freelance writer in the medical department. He studied biochemistry and pharmacy in Munich and Cambridge / Boston (USA) and noticed early on that he particularly enjoyed the interface between medicine and science. That is why he went on to study human medicine.

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The active ingredient Tadalafil is one of the most important means of treating erectile dysfunction (impotence). It belongs to the drug class of PDE-5 inhibitors. Compared to the other representatives of this class (Sildenafil, Vardenafil, Avanafil), Tadalafil has a much longer duration of action in the body. Here you can read everything you need to know about the effects and use of Tadalafil, side effects and contraindications.

This is how Tadalafil works

Erectile dysfunction

The male erection occurs after sexual arousal, either through psychological stimuli or mechanical stimulation. Nerve signals that release messenger substances in the blood vessels of the penis lead to a filling of blood in the erectile tissue of the penis. Among other things, the messenger substance "cGMP" plays a decisive role. It dilates the supplying blood vessels so that more blood flows into the erectile tissue - the limb becomes stiff. Gradually, however, this messenger substance is broken down, not least to allow the penis to relax again after sexual intercourse.

In erectile dysfunction, i.e. the inability to get or keep an erection, PDE-5 inhibitors such as tadalafil are used: They inhibit a certain enzyme (phosphodiesterase 5, PDE-5 for short) that breaks down the messenger substance cGMP. This keeps the blood level of cGMP elevated, which improves erectile function.

Benign enlargement of the prostate (benign prostatic hyperplasia)

The vessels of the prostate and the bladder behave in a similar way to the tissue of the penis. Here, too, by inhibiting the breakdown of cGMP, tadalafil can cause the muscles in the vessel walls to relax - the vessels expand, which improves blood flow. This has a positive influence on the progression of benign prostate enlargement.

High blood pressure of the pulmonary artery (pulmonary arterial hypertension)

With pulmonary hypertension, the blood pressure in the pulmonary circulation is too high (more precisely: in the pulmonary artery). Here, too, Tadalafil can relax the blood vessels and thus lower blood pressure. In the long run, this protects the vessel walls and the organs involved.

Tadalafil uptake and breakdown

Tadalafil is well absorbed into the body after ingestion and reaches its maximum concentration in the blood after two hours. In the liver, the active ingredient is broken down into ineffective metabolic products. After about 17.5 hours, half of the active ingredient is excreted - two thirds in the stool, one third in the urine.

When is Tadalafil used?

The active ingredient tadalafil is used to treat the following diseases:

• erectile dysfunction in adult men
• Pulmonary hypertension (pulmonary arterial hypertension)

Treatment is usually long-term. Only in the case of erectile dysfunction is a situation-adapted, isolated intake possible.

This is how tadalafil is used

The active ingredient is only sold in Germany in the form of tablets. To treat erectile dysfunction, it should be taken at least half an hour before sexual activity - usually ten milligrams of tadalafil are taken. It is also possible to take five milligrams a day - regardless of planned sexual activity. In this way, a constant level of active ingredient in the blood can be achieved, which means that you can plan more freely.

In the case of benign prostate enlargement and pulmonary hypertension, it is taken once a day. The usual tadalafil dosage is five milligrams or forty milligrams. It should always be taken at around the same time of day.

What are the side effects of Tadalafil?

One in ten to one hundredth patients experience Tadalafil side effects such as headache, skin redness, nasal congestion, indigestion, acid regurgitation, back pain, muscle pain and joint pain.

Furthermore, every hundredth to one thousandth person treated experiences hypersensitivity reactions, dizziness, blurred vision, eye pain, ringing in the ears, accelerated heartbeat, low or increased blood pressure, shortness of breath, nosebleeds, abdominal pain, rash, increased sweating, blood in the urine and chest pain.

What should be considered when taking Tadalafil?

Tadalafil can only be used to treat pulmonary arterial hypertension in women. Only adult men can be considered as patients for the administration of benign prostate enlargement and erectile dysfunction.

A medical examination should always be carried out before the first dose, especially with regard to the function of the heart. The dose of tadalafil should be reduced in severe renal impairment. There are no studies available on the treatment of patients with impaired liver function.

The enzymes that break down tadalafil in the liver also break down other drugs. As a result, when taken at the same time, one of the active ingredients can be strengthened, while the other is reduced to a lesser extent and thus accumulates. This applies, for example, if tadalafil is taken together with the antifungal agent ketoconazole, the HIV active ingredient ritonavir or the antibiotic erythromycin. This effect can also occur when consuming grapefruit juice.

If taken at the same time, other drugs lead to an increased breakdown of tadalafil, which reduces or even completely eliminates its effect. These include active ingredients such as the antibiotic rifampicin and the anticonvulsants phenobarbital, phenytoin and carbamazepine.

One of the most dangerous interactions can occur when taking tadalafil with nitrates to lower blood pressure. This can increase the blood pressure lowering effect excessively, which can cause the blood pressure to drop dangerously sharply. The combination of these active ingredients must therefore be avoided at all costs. The same applies to other high blood pressure drugs to a lesser extent.

How to get Tadalafil medication

All preparations with the active ingredient tadalafil require a prescription in Germany and can only be obtained in pharmacies after a doctor's prescription.

How long has tadalafil been known?

Tadalafil was brought onto the market in Germany at the end of 2002 and in the USA at the end of 2003 by the pharmaceutical company Lilly Pharma. The sexual enhancer was far superior to the active ingredient sildenafil, which had been approved four years earlier, in terms of duration of action, which is why it is sometimes called the “weekend pill”. Tadalafil generics are expected in 2016 at the earliest, as the patent for the active ingredient tadalafil will then expire - if it is not renewed.

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