Unasyn Side Effects

Generic name: ampicillin / sulbactam

Medically reviewed by Drugs.com. Last updated on Mar 1, 2024.

Note: This document provides detailed information about Unasyn Side Effects associated with ampicillin / sulbactam. Some dosage forms listed on this page may not apply specifically to the brand name Unasyn.

Applies to ampicillin / sulbactam: injection powder for solution.

Precautions

Your doctor will check you closely while you are receiving this medicine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to receive it. Blood tests may be needed to check for unwanted effects.

This medicine may cause serious allergic reactions, including anaphylaxis or certain skin conditions (eg, acute generalized exanthematous pustulosis, Stevens-Johnson syndrome). These reactions can be life-threatening and require immediate medical attention. Call your doctor right away if you have a rash, itching, blistering, peeling, or loosening of the skin, fever or chills, trouble breathing or swallowing, or any swelling of your hands, face, mouth, or throat while you are using this medicine.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Ampicillin and sulbactam combination may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop using this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.

This medicine may decrease the effects of some oral contraceptives (birth control pills). To avoid an unwanted pregnancy, it is a good idea to use additional contraceptive measures with your pills (eg, condoms, a diaphragm, or a contraceptive foam or jelly) while using this medicine.

Before you have any medical tests, tell the medical doctor in charge that you are using this medicine. The results of some tests may be affected by this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Common side effects of Unasyn

Some side effects of ampicillin / sulbactam may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects of Unasyn

Along with its needed effects, ampicillin / sulbactam 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 or nurse immediately if any of the following side effects occur while taking ampicillin / sulbactam:

For healthcare professionals

Applies to ampicillin / sulbactam: injectable powder for injection.

General adverse events

This drug was generally well-tolerated.^[Ref]

Local

• Very common (10% or more): Pain at IM injection site (16%)
• Common (1% to 10%): Pain at IV injection site, thrombophlebitis, phlebitis
• Postmarketing reports: Injections site reaction^[Ref]

Gastrointestinal

• Common (1% to 10%): Diarrhea
• Uncommon (0.1% to 1%): Nausea, vomiting, flatulence, abdominal distension, glossitis
• Frequency not reported: Pancreatitis, enterocolitis, pseudomembranous colitis
• Postmarketing reports: Gastritis, stomatitis, black "hairy" tongue, Clostridium difficile associated diarrhea^[Ref]

Hypersensitivity

• Frequency not reported: Hypersensitivity reactions to ampicillin (including urticarial rash, edema, hypotension, fever, eosinophilia, dyspnea, delayed hypersensitivity maculopapular rash, anaphylaxis, interstitial nephritis, Henoch-Schonlein purpura, focal glomerulonephritis, Stevens-Johnson syndrome)
• Postmarketing reports: Serious and fatal hypersensitivity (anaphylactic) reactions^[Ref]

Dermatologic

• Common (1% to 10%): Rash
• Uncommon (0.1% to 1%): Itching, facial swelling, erythema
• Frequency not reported: Ampicillin-associated bullous pemphigoid, linear IgA dermatosis, pseudoporphyria
• Postmarketing reports: Erythema multiforme, toxic epidermal necrolysis, Stevens-Johnson syndrome, acute generalized exanthematous pustulosis, urticaria, exfoliative dermatitis^[Ref]

Hematologic

• Frequency not reported: Decreased hemoglobin, decreased hematocrit, decreased red blood cells, decreased white blood cells, decreased neutrophils, decreased lymphocytes, decreased platelets, increased lymphocytes, increased monocytes, increased basophils, increased eosinophils, increased platelets, thrombocytopenia, leukopenia, red cell aplasia, anemia, atypical lymphocytosis
• Postmarketing reports: Hemolytic anemia, thrombocytopenic purpura, agranulocytosis, positive direct Coombs test^[Ref]

Hemolytic anemia, thrombocytopenic purpura, and agranulocytosis were generally reversible when therapy was discontinued; may be hypersensitivity events.^[Ref]

Nervous system

• Uncommon (0.1% to 1%): Headache
• Frequency not reported: Seizures, neurotoxic potential, worsening myasthenia gravis symptoms
• Postmarketing reports: Convulsion^[Ref]

Seizures have been reported in very ill patients with high serum levels of ampicillin. High cerebral spinal fluid (CSF) levels of some penicillins are potentially neurotoxic; the CSF levels of ampicillin rise significantly in meningitis.^[Ref]

Hepatic

• Frequency not reported: Increased AST, increased ALT, hepatitis, prolonged cholestasis
• Postmarketing reports: Cholestatic hepatitis, cholestasis, hyperbilirubinemia, jaundice, abnormal hepatic function^[Ref]

Metabolic

• Frequency not reported: Increased alkaline phosphatase, increased lactate dehydrogenase, decreased serum albumin, decreased total protein^[Ref]

Genitourinary

• Uncommon (0.1% to 1%): Urine retention, dysuria
• Frequency not reported: Urinary red blood cells, urinary hyaline casts^[Ref]

Renal

• Frequency not reported: Increased BUN, increased creatinine
• Postmarketing reports: Tubulointerstitial nephritis^[Ref]

Other

• Uncommon (0.1% to 1%): Candidiasis, fatigue, malaise, chest pain, edema, chills, substernal pain, mucosal bleeding^[Ref]

Respiratory

• Uncommon (0.1% to 1%): Throat tightness, epistaxis

See also:

Further information

Unasyn side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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