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Amoxicillin / clarithromycin / omeprazole Side Effects

For the Consumer

Applies to amoxicillin / clarithromycin / omeprazole: oral capsule, oral capsule delayed release, oral tablet

In addition to its needed effects, some unwanted effects may be caused by amoxicillin / clarithromycin / omeprazole. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking amoxicillin / clarithromycin / omeprazole:

Incidence not known:
  • Abdominal or stomach tenderness, cramps, or pain
  • blistering, peeling, or loosening of the skin
  • diarrhea
  • difficulty with swallowing
  • dizziness
  • fast heartbeat
  • fever or chills
  • hives or welts, itching, or skin rash
  • joint or muscle pain
  • muscle pain or weakness
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • redness of the skin
  • sores, ulcers, or white spots in the mouth or on the lips
  • swelling of the body, feet, and ankles
  • tightness in the chest
  • unusual tiredness or weakness
  • unusual weight gain
  • watery and severe diarrhea, which may also be bloody

Minor Side Effects

Some of the side effects that can occur with amoxicillin / clarithromycin / omeprazole may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Bad, unusual, or unpleasant (after) taste
  • change in taste
  • headache

For Healthcare Professionals

Applies to amoxicillin / clarithromycin / omeprazole: oral kit


The most frequently reported side effects observed using combination therapy with omeprazole, clarithromycin and amoxicillin were diarrhea, taste perversion and headache[Ref]


Postmarketing reports: QT prolongation and ventricular arrhythmias, including ventricular tachycardia and torsades de pointes

Postmarketing reports: Chest pain or angina, tachycardia, bradycardia, palpitations, elevated blood pressure, peripheral edema[Ref]


Postmarketing reports: Severe generalized skin reactions including toxic epidermal necrolysis (some fatal), Stevens-Johnson syndrome, and erythema multiforme; photosensitivity; urticaria; rash; skin inflammation; pruritus; petechiae; purpura; alopecia; dry skin; hyperhidrosis[Ref]


Postmarketing reports: Gynecomastia[Ref]


Postmarketing reports: Nausea, vomiting, diarrhea, and hemorrhagic/Clostridium difficile-associated colitis, tooth discoloration

Common (1% to 10%): Diarrhea, nausea, abnormal taste, dyspepsia, abdominal pain/discomfort
Postmarketing reports: Glossitis, stomatitis, oral moniliasis, anorexia, vomiting, pancreatitis, tongue discoloration, tooth discoloration

Common (1% to 10%): Abdominal pain, nausea, diarrhea, vomiting, flatulence, acid regurgitation, constipation
Postmarketing reports: Pancreatitis, anorexia, irritable colon, fecal discoloration, esophageal candidiasis, mucosal atrophy of the tongue, stomatitis, abdominal swelling, dry mouth, gastric fundic gland polyps, gastroduodenal carcinoids, taste perversion[Ref]


Postmarketing reports: Interstitial nephritis, hematuria, proteinuria, elevated serum creatinine, microscopic pyuria, urinary tract infection, glycosuria, urinary frequency, testicular pain[Ref]


Postmarketing reports: Anemia, including hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia, agranulocytosis, decrease WBC, elevated prothrombin time

Postmarketing reports: Thrombocytopenia, leukopenia, neutropenia

Postmarketing reports: Agranulocytosis (some fatal), hemolytic anemia, pancytopenia, neutropenia, anemia, thrombocytopenia, leukopenia, leucocytosis[Ref]


Postmarketing reports: Moderate rise in AST (SGOT) and/or ALT (SGPT), hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis

Postmarketing reports: Hepatic dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, hepatic failure with fatal outcomes

Postmarketing reports: Liver disease including hepatic failure (some fatal), liver necrosis (some fatal), hepatic encephalopathy hepatocellular disease, cholestatic disease, mixed hepatitis, jaundice, and elevations of liver function tests[Ref]


Postmarketing reports: Serum sickness like reactions, erythematous maculopapular rashes, erythema multiforme, Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, hypersensitivity vasculitis and urticaria

Postmarketing reports: Allergic reactions ranging from urticaria and mild skin eruptions to rare cases of anaphylaxis, Stevens-Johnson syndrome, and toxic epidermal necrolysis have occurred[Ref]


Postmarketing reports: Hypoglycemia

Postmarketing reports: Hypoglycemia, hyponatremia, weight gain[Ref]


Common (1% to 10%): Asthenia, back pain
Postmarketing reports: Muscle weakness, myalgia, muscle cramps, joint pain, leg pain[Ref]

Nervous system

Postmarketing reports: Reversible hyperactivity, agitation, insomnia, confusion, dizziness

Common (1% to 10%): Headache
Postmarketing reports: Hearing loss, alterations of sense of smell, tinnitus, dizziness, vertigo, convulsions, insomnia, tremor

Common (1% to 10%): Headache, dizziness
Postmarketing reports: Nervousness, insomnia, somnolence, tinnitus[Ref]


Postmarketing reports: Optic atrophy, anterior ischemic optic neuropathy, optic neuritis, dry eye syndrome, ocular irritation, blurred vision, double vision[Ref]


Postmarketing reports: Anxiety, behavioral changes

Postmarketing reports: Anxiety, behavioral changes, confusional states, depersonalization, disorientation, hallucinations, manic behavior, nightmares, psychosis

Postmarketing reports: Psychiatric and sleep disturbances including depression, agitation, aggression, hallucinations, confusion, apathy, anxiety, and dream abnormalities[Ref]


Postmarketing reports: Crystalluria, elevated BUN, elevated serum creatinine

Postmarketing reports: Interstitial nephritis[Ref]


Common (1% to 10%): Upper respiratory infection, cough
Postmarketing reports: Epistaxis, pharyngeal pain[Ref]


1. "Product Information. Omeclamox-Pak (amoxicillin / clarithromycin / omeprazole)." Pernix Therapeutics, Magnolia, TX.

Not all side effects for amoxicillin / clarithromycin / omeprazole may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.