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Amoxicillin / vonoprazan Side Effects

Medically reviewed by Last updated on Oct 22, 2023.

Applies to amoxicillin / vonoprazan: oral capsule, oral tablet.

Serious side effects

Along with its needed effects, amoxicillin / vonoprazan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking amoxicillin / vonoprazan:

More common

Less common

Incidence not known

For Healthcare Professionals

Applies to amoxicillin / vonoprazan: oral kit.


The most common adverse reaction leading to discontinuation of this product was rash.[Ref]


Common (1% to 10%): Hypertension (includes increased blood pressure)

Frequency not reported: QT prolongation, tachycardia[Ref]


Frequency not reported: Dermatitis, dry skin, rash

Amoxicillin and Vonoprazan:

-Frequency not reported: Severe cutaneous adverse reactions (including Stevens-Johnson syndrome, toxic epidermal necrolysis)


-Frequency not reported: Erythematous skin rash

-Postmarketing reports: Mucocutaneous candidiasis, erythematous maculopapular rashes, erythema multiforme, exfoliative dermatitis, urticaria, toxic epidermal necrolysis, Stevens-Johnson syndrome, drug reaction with eosinophilia and systemic symptoms (DRESS), acute generalized exanthematous pustulosis


-Postmarketing reports: Urticaria, drug eruption, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis[Ref]


Common (1% to 10%): Diarrhea, abdominal pain (includes abdominal discomfort, abdominal pain, lower abdominal pain, upper abdominal pain)

Frequency not reported: Abdominal distension, constipation, dry mouth, duodenal polyp, duodenal ulcer, dyspepsia, flatulence, gastric ulcer, gastroesophageal reflux disease, hematochezia, large intestine polyp, nausea, rectal polyp, stomatitis, tongue discomfort, vomiting, anal fungal infection, gastrointestinal viral infection, oral fungal infection, tongue fungal infection


-Frequency not reported: Clostridioides difficile-associated diarrhea

-Postmarketing reports: Black hairy tongue, hemorrhagic/pseudomembranous colitis, tooth discoloration (brown, yellow, or gray staining)

Acid-Suppressing Therapies:

-Frequency not reported: C difficile-associated diarrhea[Ref]

Onset of pseudomembranous colitis symptoms has been reported during or after antibacterial treatment.

Most reports of tooth discoloration with amoxicillin occurred in pediatric patients; discoloration was reduced/eliminated with brushing or dental cleaning in most cases.[Ref]


Common (1% to 10%): Vulvovaginal candidiasis (includes urogenital fungal infection, vulvovaginal candidiasis, vulvovaginal mycotic infection, vulvovaginal pruritus, genital pruritus, genital fungal infection)

Frequency not reported: Urinary tract infection, vaginal discharge


-Postmarketing reports: Crystalluria[Ref]


Hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, and agranulocytosis have been reported during therapy with penicillins; these reactions were usually reversible when therapy was stopped and were believed to be hypersensitivity phenomena.[Ref]

Frequency not reported: Anemia, leukocytosis, leukopenia, neutropenia


-Postmarketing reports: Hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, agranulocytosis[Ref]


Frequency not reported: Abnormal liver function test


-Postmarketing reports: Hepatic injury, hepatic failure, jaundice[Ref]


Frequency not reported: Drug hypersensitivity

Amoxicillin and Vonoprazan:

-Frequency not reported: Hypersensitivity reactions (e.g., anaphylaxis, anaphylactic shock, rash, erythema multiforme, Henoch-Schonlein purpura)


-Postmarketing reports: Anaphylaxis, serum sickness-like reactions, hypersensitivity vasculitis


-Postmarketing reports: Anaphylactic shock[Ref]


Frequency not reported: Decreased appetite[Ref]


Frequency not reported: Bone fracture[Ref]

Nervous system

Common (1% to 10%): Headache

Uncommon (0.1% to 1%): Dysgeusia (includes taste disorder)

Frequency not reported: Ageusia, dizziness, tension headache


-Postmarketing reports: Reversible hyperactivity, convulsions, aseptic meningitis[Ref]


Frequency not reported: Orbital edema[Ref]


Frequency not reported: Fatigue, pyrexia, viral infection[Ref]


Frequency not reported: Anxiety, depression, insomnia


-Postmarketing reports: Agitation, confusion, behavioral changes[Ref]


Frequency not reported: Renal hypertrophy, tubulointerstitial nephritis[Ref]


Common (1% to 10%): Nasopharyngitis

Frequency not reported: Pneumonia, upper respiratory tract infection, cough, nasal polyps, oropharyngeal pain[Ref]


1. Product Information. Voquezna Dual Pak (amoxicillin-vonoprazan). Phathom Pharmaceuticals, Inc. 2022.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.