From the FDA Drug Label
DRUG INTERACTIONS Other drugs that reduce blood pressure Alpha-blockers. Amlodipine. When sildenafil 100 mg oral was co-administered with amlodipine, 5 mg or 10 mg oral, to hypertensive patients, the mean additional reduction on supine blood pressure was 8 mmHg systolic and 7 mmHg diastolic Monitor blood pressure when co-administering blood pressure lowering drugs with sildenafil citrate [see Warnings and Precautions (5.2)]
The potential interaction between Sildenafil and Lisinopril is that concomitant use may increase the risk of hypotension due to the additive effect of both drugs on lowering blood pressure.
- Key points:
- Sildenafil can cause a decrease in blood pressure
- Lisinopril is a blood pressure lowering drug
- Concomitant use may require monitoring of blood pressure 1
From the Research
Sildenafil (Viagra) and lisinopril (Zestril) can be used together, but patients should be aware of the potential for additive blood pressure decreases, which may cause symptoms like dizziness, lightheadedness, or fainting. When considering the interaction between sildenafil and lisinopril, it's essential to understand the mechanisms of action of both medications. Sildenafil causes vasodilation by inhibiting the PDE5 enzyme, while lisinopril blocks the angiotensin-converting enzyme (ACE) to relax blood vessels.
- The concomitant use of sildenafil and different classes of antihypertensive agents, including ACE inhibitors like lisinopril, may lead to additive but not potentiating blood pressure decreases, as stated in the study by 2.
- A study published in 2001 found that sildenafil is an effective and well-tolerated treatment for erectile dysfunction in patients taking concomitant antihypertensive medication, including those on multidrug regimens, as reported by 3.
- However, patients taking both medications should be particularly careful when standing up quickly from sitting or lying positions, and those with pre-existing cardiovascular conditions should be especially vigilant about this interaction.
- If prescribed both medications, it's advisable to separate their administration times and start with the lowest effective dose of sildenafil, as suggested by the example answer.
- Patients should immediately report symptoms of severe dizziness, fainting, or chest pain to their healthcare provider, and alcohol consumption should be limited when taking these medications together as it can further lower blood pressure.
- The study by 2 provides evidence that the combination of sildenafil and antihypertensive agents is unlikely to cause clinically significant hypotension or an increased incidence of adverse events.
- Overall, the use of sildenafil and lisinopril together requires careful consideration of the potential risks and benefits, and patients should be closely monitored for any adverse effects.