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Ampicillin Side Effects

The most commonly reported side effects of ampicillin include foetal exposure during pregnancy, drug hypersensitivity, and maternal exposure during pregnancy, based on 11,255 FDA adverse event reports from 2004 to 2025. 8.2% of reports found the drug to be ineffective.

Ampicillin side effects

Percentages show how often each reaction appears relative to total reports for ampicillin.

1
Drug Ineffective8.2%928
2
Foetal Exposure During Pregnancy6.0%678
3
Drug Hypersensitivity5.8%656
4
Maternal Exposure During Pregnancy5.1%574
5
Off Label Use4.6%515
6
Premature Baby4.5%510
7
Pyrexia3.7%422
8
Acute Kidney Injury3.4%384
9
Premature Delivery3.3%369
10
Pneumonia3.0%336
11
Product Use In Unapproved Indication2.8%315
12
Renal Failure2.7%301
13
Chronic Kidney Disease2.7%299
14
Rash2.6%293
15
Diarrhoea2.6%291

These are voluntary reports and do not establish that ampicillin caused these reactions.

Report severity

88.6%Serious9,976 reports
44.4%Hospitalizations4,998 reports
17.0%Fatal1,912 reports

Seriousness is determined by the reporter, not by OpenClaim.

Ampicillin drug interactions

Other drugs that appear in adverse event reports alongside ampicillin. Drugs flagged as a suspected cause appear in the first column. Drugs taken at the same time but not suspected appear in the second.

Also suspected

1
Sulbactam-sodium11.1%1,244
2
Gentamicin-sulfate10.9%1,226
3
Vancomycin8.1%911
4
Azithromycin7.3%825
5
Ceftriaxone-sodium6.1%692
6
Meropenem4.8%543
7
Betamethasone4.8%536
8
Amoxicillin4.5%511
9
Ciprofloxacin3.6%408
10
Dextrose3.2%362
11
Metronidazole3.2%355
12
Omeprazole3.1%353
13
Magnesium-sulfate2.9%329
14
Dexamethasone2.7%301
15
Clindamycin2.7%301

Taken alongside

1
Sulbactam-sodium15.3%1,726
2
Acetaminophen12.3%1,389
3
Furosemide8.8%985
4
Vancomycin8.4%943
5
Aspirin7.1%801
6
Gentamicin-sulfate7.1%799
7
Ceftriaxone-sodium6.5%734
8
Amoxicillin6.1%685
9
Dexamethasone5.6%630
10
Acyclovir5.4%610
11
Amlodipine5.2%590
12
Pantoprazole-sodium5.2%587
13
Ondansetron5.2%582
14
Omeprazole4.9%555
15
Prednisone4.8%544

Co-occurrence in adverse event reports does not establish a drug interaction. Patients often take multiple medications, and these lists reflect prescribing patterns rather than causal relationships. Consult a healthcare provider about potential drug interactions.

Who reports ampicillin side effects

48.8% of ampicillin adverse event reports involve female patients and 39.7% involve male patients. The largest age group is adult at 46%. These figures reflect who reports side effects, not underlying risk.

Sex

Female48.8%
Male39.7%
Unknown11.5%

Age group

< 216.8%
2–113.9%
12–172.3%
18–6445.9%
65+31.2%

What is ampicillin used for

Conditions and purposes for which patients were taking ampicillin when the adverse event was reported.

Abdominal AbscessAbdominal DiscomfortAbdominal InfectionAbdominal PainAbortion ThreatenedAbscessAbscess NeckAcinetobacter InfectionAcneAcne CysticActinomycosisAcute AbdomenAcute Disseminated EncephalomyelitisAcute EndocarditisAcute Focal Bacterial Nephritis

Showing 15 of 892 indications

Ampicillin brand names and reporting trend

Ampicillin is sold under brand names including Principen W/ Probenecid, Totacillin-n.

Brand names

Principen W/ Probenecid8,428
Totacillin-n1,019

Quarterly reports (20042025)

20052010201520202025

An upward trend reflects increased FAERS reporting overall, not necessarily increased risk.

Taking ampicillin with another medication?

Ask OpenClaim about your specific drug combination. Get a sourced report using FDA data, drug labels, and medical literature.