Final answer:
Phosphodiesterase-5 inhibitors like sildenafil can cause hypotension when combined with certain medications, such as nitrates. Individuals with cardiac disease should avoid using sildenafil without medical guidance.
Step-by-step explanation:
Phosphodiesterase-5 inhibitors (such as sildenafil) can cause hypotension when taken in combination with certain medications. One example is the combination of sildenafil and nitrates, which can lead to a dangerous drop in blood pressure. Nitrates are commonly prescribed for heart conditions, so individuals with cardiac disease should avoid taking sildenafil without consulting their physician. It is important to be cautious when using phosphodiesterase-5 inhibitors and to follow the advice of healthcare professionals.