Amox clav 875 is a prescription antibiotic tablet containing 875 mg of amoxicillin and 125 mg of clavulanate potassium. It’s one of the most commonly prescribed antibiotics in the United States, used to treat bacterial infections that plain amoxicillin can’t always handle on its own. If you’ve just picked this up from the pharmacy, here’s what you’re actually taking and what to expect.
What the Two Ingredients Do
Amoxicillin is the antibiotic doing the heavy lifting. It belongs to the penicillin family and works by stopping bacteria from building their cell walls, which kills them. The problem is that many bacteria have learned to fight back by producing enzymes that break down amoxicillin before it can work.
That’s where clavulanate comes in. It isn’t really an antibiotic itself. It acts as a shield for the amoxicillin, blocking those bacterial enzymes so the amoxicillin can do its job. This combination makes the medication effective against a wider range of bacteria than amoxicillin alone. Every tablet at this strength contains the same fixed ratio: 875 mg of amoxicillin paired with 125 mg of clavulanate.
What It’s Prescribed For
Doctors prescribe amox clav 875 for bacterial infections in several parts of the body. The most common reasons include sinus infections, ear infections, lower respiratory infections like bronchitis or pneumonia, urinary tract infections, and skin infections (particularly bite wounds or infected cuts where multiple types of bacteria may be involved). It’s also frequently used for dental infections and abscesses.
This medication only works against bacteria. It won’t help with viral infections like the common cold or flu, and using it unnecessarily can contribute to antibiotic resistance.
How to Take It
The standard schedule for the 875 mg strength is one tablet every 12 hours, so you’ll typically take it twice a day. A full course usually lasts 7 to 14 days depending on the type and severity of your infection.
You can technically take it with or without food, but there are good reasons to eat something first. The FDA prescribing information notes that absorption of the clavulanate component improves when taken at the start of a meal. More importantly for your comfort, taking it with food significantly reduces the chance of stomach upset, which is the most common complaint with this medication. Even a small snack helps.
Finish the entire course your doctor prescribed, even if you start feeling better after a few days. Stopping early gives surviving bacteria a chance to bounce back, potentially causing a harder-to-treat infection.
Common Side Effects
The clavulanate component is responsible for most of the side effects people experience. Diarrhea is the most frequent one, affecting a notable percentage of people who take the medication. Other common effects include nausea, vomiting, and general stomach discomfort. These tend to be mild and improve once you finish the course.
Because antibiotics kill beneficial gut bacteria along with the harmful ones, yeast infections (particularly vaginal yeast infections) can develop during or shortly after treatment. Eating yogurt with live cultures or taking a probiotic supplement may help maintain your gut balance, though spacing the probiotic a couple of hours away from your antibiotic dose is a good idea.
Skin rashes occur in some people. A mild, flat rash without itching is relatively common with amoxicillin and isn’t always a true allergy. However, hives, swelling of the face or throat, or difficulty breathing are signs of a serious allergic reaction that needs immediate medical attention.
Penicillin Allergy and This Medication
Since amoxicillin is a penicillin-type antibiotic, anyone with a confirmed penicillin allergy should not take amox clav 875 without medical guidance. That said, penicillin allergy is widely over-reported. Research published in The Journal of Allergy and Clinical Immunology: In Practice found that fewer than 1 in 20 people who believe they’re allergic to penicillin actually react when given a supervised test dose. Many people labeled as allergic in childhood have outgrown it or never had a true allergy in the first place.
If you have a documented penicillin allergy, your doctor may recommend allergy testing before prescribing this medication, or they may choose a different antibiotic class entirely. The key distinction is between a mild childhood rash (which often isn’t a true allergy) and a history of hives, throat swelling, or anaphylaxis (which is).
Liver Concerns
The clavulanate component can, in rare cases, cause liver irritation. People who have previously experienced jaundice (yellowing of the skin or eyes) or liver problems while taking amoxicillin-clavulanate should not take it again. Symptoms to watch for include dark urine, pale stools, persistent nausea, or a yellowish tint to your skin or the whites of your eyes. These effects can sometimes appear days or even weeks after finishing the course.
Why 875 Instead of 500
Amox clav comes in multiple strengths. The two most common adult formulations are 500 mg and 875 mg, and both contain the same 125 mg of clavulanate. The 500 mg version is typically taken three times a day (every 8 hours), while the 875 mg version is taken twice a day (every 12 hours). Your doctor chooses between them based on the severity of your infection and convenience. The 875 mg, twice-daily schedule is easier to stick to and is the more commonly prescribed adult dose for moderate to severe infections.
The clavulanate amount stays at 125 mg per tablet regardless of the amoxicillin strength. This is intentional, because higher doses of clavulanate increase the risk of digestive side effects without adding antibacterial benefit. You should not substitute two 500 mg tablets for one 875 mg tablet, since that would double your clavulanate intake.
Interactions Worth Knowing About
Amox clav can reduce the effectiveness of hormonal birth control pills, though the clinical significance of this is debated. Using a backup method of contraception during your antibiotic course is a reasonable precaution. The medication can also interact with blood thinners, increasing their effect, so your doctor may want to monitor your clotting levels if you take both.
Alcohol doesn’t have a dangerous interaction with amox clav, but it can worsen the stomach side effects and slow your recovery from the infection. Keeping alcohol to a minimum during treatment is practical advice more than a strict medical rule.