Talafil (Cialis): situations where its use is not recommended
tadalafil (tadalafil) has the following main contraindications:
1. Nitrate interaction
Mechanism: Tadalafil is a phosphodiesterase inhibitor-5 (PDE-5). Nitrates (e.g. nitroglycerin, isosorbide mononitrate, isosorbide dinitrate) are used to treat angina pectoris and act by releasing nitric oxide, which relaxes smooth vascular muscles. The combination with tadalafil may enhance the hypotensive action of nitric oxide, which can lead to a drastic drop in systolic and diastolic blood pressure, which in turn can lead to severe hypotension, dizziness, fainting and, in extreme cases, brain or cardiac damage.
Recommendation: the combination of tadalafil and nitrates is absolutely contraindicated. Patients taking nitrates in any form (sublingual, transdermal, oral, etc.) They should not receive tadalafil.
2. Hypersensitivity to tadalafil or any of the ingredients of the formula
Mechanism: a defense mechanism of the organism in response to a substance perceived as strange and potentially harmful. The reaction can range from a mild rash to a severe anaphylactic reaction, which can compromise breathing and blood circulation.
Recommendation: in case of known hypersensitivity to tadalafil, this drug should not be administered.
3. Severe cardiac abnormalities
Mechanism: in patients with certain complex and severe heart diseases, tadalafil induced vasodilation may pose an additional risk for cardiac function and hemodynamic stability. For example, in patients with severe heart failure (class III-IV of the New York heart Association), a drop in tadalafil induced blood pressure can worsen blood flow to the heart and the rest of the body, exacerbating heart failure.
Recommendation: Tadalafil should be used with caution or may be contraindicated in these patients, and its use should be carefully evaluated by a cardiologist.
4. Unstable blood pressure
MechanismSince tadalafil may cause a decrease in blood pressure, in patients with unstable blood pressure (e.g. those with severe chronic hypotension or sudden and uncontrolled changes in blood pressure), the administration of tadalafil may exacerbate hemodynamic instability.
Recommendation: tadalafil should be avoided until blood pressure has stabilized properly.
5. Concomitant use with certain potent CYP3A4 inhibitors
Mechanism: Tadalafil is metabolised in part by cytochrome P450 3A4 (CYP3A4) in the liver. Potent CYP3A4 inhibitors (such as ritonavir, ketoconazole) may increase the blood concentration of tadalafil, increasing the risk of adverse effects, particularly hypotension and other effects associated with increased drug exposure.
RecommendationIn general, the combination should be avoided or, if necessary, tadalafil dose adjusted and the patient carefully monitored.