Yes, you can take amoxicillin with lisinopril. There is no recognized drug interaction between these two medications, and they are routinely prescribed together. Major drug interaction databases list no direct conflicts between them, so if your doctor has prescribed both, you can take them as directed without needing to separate doses or adjust timing.
That said, there are a few practical things worth knowing about how these drugs behave in your body at the same time, especially when it comes to side effects that overlap.
Why These Two Don’t Conflict
Amoxicillin is a penicillin-type antibiotic, most often prescribed for infections like strep throat, ear infections, sinus infections, and urinary tract infections. Lisinopril is an ACE inhibitor used to lower blood pressure and protect the heart and kidneys. They work through completely different mechanisms, and neither drug meaningfully changes how the other is absorbed or used by the body.
Both drugs are cleared primarily through the kidneys. About 50 to 70 percent of amoxicillin leaves your body unchanged in urine, and 80 to 90 percent of lisinopril does the same. In theory, two drugs that rely heavily on the kidneys could compete for the same elimination pathways, but amoxicillin and lisinopril use different renal transport systems. There’s no documented evidence that one slows down or interferes with the clearance of the other at normal doses.
Diarrhea Is the Overlap to Watch
The most relevant practical concern isn’t a true drug interaction. It’s that both medications can independently cause diarrhea, and taking them together may make that more likely or more noticeable.
Amoxicillin, like most antibiotics, disrupts the normal bacteria in your gut. This frequently leads to loose stools or diarrhea during and shortly after a course of treatment. The effect is even more common with amoxicillin-clavulanate (the combination version sometimes sold as Augmentin), but plain amoxicillin can do it too.
Lisinopril can also cause diarrhea on its own, though it’s less common. In some people, ACE inhibitors trigger watery diarrhea through an unclear mechanism. In rare cases, the diarrhea is linked to a form of intestinal swelling related to how the drug affects certain chemical pathways in the body. Some observational studies have even connected lisinopril to microscopic colitis, a condition that causes persistent watery diarrhea.
If you experience significant diarrhea while taking both, it matters because fluid loss and dehydration can amplify lisinopril’s blood-pressure-lowering effect. ACE inhibitors are more likely to cause a drop in blood pressure in people who are dehydrated or low on sodium. Symptoms of this include dizziness, lightheadedness, or feeling faint when you stand up. Staying well hydrated during your antibiotic course helps prevent this chain reaction.
Blood Pressure May Shift Slightly
Being sick with an infection can itself affect your blood pressure, sometimes raising it due to stress and inflammation, sometimes lowering it if you’re not eating or drinking normally. Animal research has shown that amoxicillin may modestly lower blood pressure by changing the composition of gut bacteria, though this effect has not been confirmed in human studies and is unlikely to be significant during a standard 7- to 10-day antibiotic course.
The practical takeaway: if you feel unusually dizzy or lightheaded while taking both medications, it’s probably related to dehydration or the infection itself rather than a direct drug conflict. Drinking enough fluids and eating regularly will do more than any dose adjustment.
Angioedema: Rare but Worth Knowing
Both ACE inhibitors and penicillin-type antibiotics are independently linked to angioedema, a type of swelling that typically affects the face, lips, tongue, or throat. With ACE inhibitors like lisinopril, angioedema occurs in roughly 0.1 to 0.7 percent of users. Penicillin-class antibiotics (which include amoxicillin) are also listed among drugs that can rarely trigger this reaction.
There is no evidence that taking them together increases the risk beyond what each carries alone. But if you’ve ever experienced swelling of the face, lips, or throat while taking either medication in the past, that’s important information to share with your prescriber before starting the other one.
No Special Timing Needed
Unlike some drug combinations that require you to space out doses by a few hours, amoxicillin and lisinopril don’t need any special scheduling. You can take them at the same time of day or at different times, whatever fits your routine. Neither drug blocks the absorption of the other.
The one thing that does help: take your full course of amoxicillin as prescribed, even if you start feeling better. Stopping early increases the chance of the infection coming back, which means another round of antibiotics and more time for side effects to stack up. Continue taking lisinopril on your normal schedule throughout. There’s no reason to pause or adjust your blood pressure medication while on amoxicillin.