Ampicillin/Sulbactam: Side Effects, Uses, Dosage, Interactions, Warnings

Ampicillin/Sulbactam

What Is Ampicillin/Sulbactam and How Does It Work?

Ampicillin/Sulbactam is a prescription medication used to treat the symptoms of bacterial infections such as Gynecologic Infections, Intra-Abdominal Infections, Skin and Skin Structure Infections, Orbital Cellulitis, Pelvic Inflammatory Disease, Pneumonia, and Urinary Tract Infections. 

  • Ampicillin/Sulbactam is available under the following different brand names: Unasyn

What Are Dosages of Ampicillin/Sulbactam?

Dosages of Ampicillin/Sulbactam:

Adult and Pediatric dosage

Powder for Solution

  • 1.5g (ampicillin 1g/sulbactam 0.5g)
  • 3g (ampicillin 2g/sulbactam 1g)
  • 15g (ampicillin 10g/sulbactam 5g)

Gynecologic Infections

  • 1.5 g (1 g ampicillin/0.5 g sulbactam) to 3 g (2 g ampicillin/1 g sulbactam) via IV or IM every 6 hours; not to exceed 12 g/day

Intra-Abdominal Infections

  • 1.5 g (1 g ampicillin/0.5 g sulbactam) to 3 g (2 g ampicillin/1 g sulbactam) via IV or IM every 6 hours; not to exceed 12 g/day

Skin & Skin Structure Infections

Adult dosage

  • 1.5 g (1 g ampicillin/0.5 g sulbactam) to 3 g (2 g ampicillin/1 g sulbactam) via IV or IM every 6 hours; not to exceed 12 g/day

Pediatric dosage

  • Children older than 1 year of age, weighing less than 40 kg: 200 mg/kg/day via IV divided every 6 hours; not to exceed 14 days of therapy. 
  • Children older than 1 year of age, weighing over 40 kg: 1.5g (1 g ampicillin/0.5 g sulbactam) to 3 g (2 g ampicillin/1 g sulbactam) every 6 hours; not to exceed 12 g/day

Orbital Cellulitis

  • 3 g (2 g ampicillin/1 g sulbactam) via IV every 6 hours

Pelvic Inflammatory Disease

  • 3 g (2 g ampicillin/1 g sulbactam) via IV every 6 hours

Pneumonia

  • Aspiration or community-acquired: 1.5 g (1 g ampicillin/0.5 g sulbactam) to 3 g (2 g ampicillin/1 g sulbactam) via IV every 6 hours for 5 or more days
  • Hospital-acquired: 3 g via IV every 6 hours for 5 or more days

Urinary Tract Infections

  • Pyelonephritis: 3 g (2 g ampicillin/1 g sulbactam) via IV every 6 hours for 14 days

Epiglottitis

Pediatric dosage

  • Children and adolescents: 100-200 mg ampicillin/kg/day IV divided every 6 hours

Mild/Moderate Infection

Pediatric dosage

  • Children older than 1 month -1 year: 100-150 mg ampicillin/kg/day via IV or IM divided every 6 hours  
  • Children older than 1 year: 100-200 mg ampicillin/kg/day via IV or IM divided every 6 hours

Meningitis/Severe Infections

Pediatric dosage

  • Children older than 1 month-1 year: 200-300 mg ampicillin/kg/day via IV or IM divided every 6 hours  
  • Children older than 1 year: 200-400 mg ampicillin/kg/day via IV or IM divided every 6 hours

Peritonsillar and Retropharyngeal Abscess

Pediatric dosage

  • Children and adolescents: 200 mg ampicillin/kg/day via IV divided every 6 hours

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”.

What Are Side Effects Associated with Using Ampicillin/Sulbactam?

Common side effects of Ampicillin/Sulbactam include:

  • diarrhea, 
  • rash, 
  • swollen, black, or “hairy” tongue, 
  • vaginal itching or discharge, and 
  • pain at the injection site

Serious side effects of Ampicillin/Sulbactam include:

  • hives, 
  • difficulty breathing, 
  • swelling of the face, lips, tongue, or throat, 
  • fever, 
  • sore throat
  • burning eyes, 
  • skin pain, 
  • red or purple skin rash with blistering and peeling, 
  • severe stomach pain, 
  • diarrhea that is watery or bloody (even if it occurs months after the last dose), 
  • white patches inside the  mouth or throat, 
  • fast heartbeats, 
  • chest pain or pressure, 
  • pain spreading to the jaw or shoulder
  • nausea, 
  • sweating, 
  • upper stomach pain, 
  • itching, 
  • tired feeling, 
  • loss of appetite, 
  • dark urine, 
  • clay-colored stools, 
  • yellowing of the skin or eyes (jaundice), 
  • headache, 
  • tiredness, 
  • ear pain or drainage, 
  • eye pain or redness, 
  • cough, 
  • skin rash, 
  • sores or pimples with pus
  • joint pain,
  • ongoing neck or back pain
  • diarrhea, and
  • pain or burning during urination

Rare side effects of Ampicillin/Sulbactam include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What other drugs interact with Ampicillin/Sulbactam?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Ampicillin/Sulbactam has severe interactions with no other drugs.
  • Ampicillin/Sulbactam has serious interactions with at least 12 other drugs.
  • Ampicillin/Sulbactam has moderate interactions with at least 30 other drugs.
  • Ampicillin/Sulbactam has minor interactions with at least 18 other drugs.

This information does not contain all possible interactions or adverse effects.  Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use.  Keep a list of all your medications with you, and share this information with your doctor and pharmacist.  Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What are warnings and precautions for Ampicillin/Sulbactam?

Contraindications

  • Hypersensitivity to drug or components
  • Patient with the previous history of cholestatic jaundice or hepatic dysfunction associated with ampicillin sulbactam

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Ampicillin/Sulbactam?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Ampicillin/Sulbactam?”

Cautions

  • Use caution in patients with allergies to cephalosporins and carbapenems
  • Adjust dose in renal failure
  • Prolonged use is associated with fungal or bacterial superinfection
  • Hepatic dysfunction, including hepatitis and cholestatic jaundice, reported; hepatic toxicity is usually reversible; however, deaths have occurred; monitor hepatic function at regular intervals in patients with hepatic impairment
  • A generalized dull red maculopapular rash may occur in 5-10% of children 3-14 days after initiating therapy; carefully evaluate the rash to differentiate a nonallergic ampicillin rash from a hypersensitivity reaction; it normally begins on the trunk and spreads over most of the body; it may be most intense at pressure areas, elbows, and knees
  • Hepatotoxicity reported; monitor hepatic function at regular intervals in patients with hepatic impairment
  • A high percentage of patients with infectious mononucleosis have developed a rash during therapy; therapy is not recommended in these patients
  • May cause severe skin reactions, such as toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), dermatitis exfoliative, erythema multiforme, and acute generalized exanthematous pustulosis (AGEP); if patients develop skin rash monitor closely and discontinued therapy if lesions progress

Pregnancy and Lactation

  • Use may be acceptable during pregnancy.  
  • Medication is excreted in breast milk; use with caution.
References

Medscape. Ampicillin/Sulbactam.
https://reference.medscape.com/drug/unasyn-ampicillin-sulbactam-342476