Unasyn 15gm Inj, 1 Vial
It is used to treat bacterial infections.
Drug Class
Antibiotic
Pharmacologic Class
Penicillin/Beta-lactamase Inhibitor Combination
Pregnancy Category
Category B
FDA Approved
Feb 1986
DEA Schedule
Not Controlled
Overview
What is this medicine?
Ampicillin and sulbactam is an antibiotic medication used to treat various bacterial infections. Ampicillin kills bacteria by stopping them from building their cell walls, and sulbactam helps ampicillin work better by protecting it from certain bacterial defenses.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Administer the medication as directed, which may involve receiving it as an injection into a muscle or as an infusion into a vein over a period of time. In some cases, it may be given as an injection directly into a vein.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
Missing a Dose
If you miss a dose, contact your doctor to receive guidance on what to do next.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Administer the medication as directed, which may involve receiving it as an injection into a muscle or as an infusion into a vein over a period of time. In some cases, it may be given as an injection directly into a vein.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
Missing a Dose
If you miss a dose, contact your doctor to receive guidance on what to do next.
Lifestyle & Tips
- Complete the full course of medication as prescribed, even if you start feeling better, to prevent the infection from returning and to reduce the risk of antibiotic resistance.
- Report any new or worsening symptoms to your healthcare provider.
- Maintain good hygiene to prevent the spread of infection.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
1.5 g (1 g ampicillin/0.5 g sulbactam) to 3 g (2 g ampicillin/1 g sulbactam) IV or IM every 6 hours
Dose Range:
1.5 - 3 mg
Condition-Specific Dosing:
mild_moderate_infections:
1.5 g every 6 hours
severe_infections:
3 g every 6 hours
maximum_daily_dose:
12 g (8 g ampicillin/4 g sulbactam) per day
Pediatric Dosing
Neonatal:
Not established for neonates < 1 week old. For 1 week to 1 month: 75 mg/kg/day (50 mg ampicillin/25 mg sulbactam) divided every 12 hours.
Infant:
150 mg/kg/day (100 mg ampicillin/50 mg sulbactam) divided every 6-8 hours
Child:
150 mg/kg/day (100 mg ampicillin/50 mg sulbactam) divided every 6-8 hours (Max 12 g/day)
Adolescent:
Same as adult dosing (1.5 g to 3 g IV or IM every 6 hours)
Dose Adjustments
Renal Impairment:
Mild:
CrCl > 30 mL/min: No adjustment needed.
Moderate:
CrCl 15-29 mL/min: Administer 1.5 g to 3 g every 8 hours.
Severe:
CrCl 5-14 mL/min: Administer 1.5 g to 3 g every 12-24 hours.
Dialysis:
Hemodialysis: Administer dose after dialysis. Both ampicillin and sulbactam are removed by hemodialysis.
Hepatic Impairment:
Mild:
No specific adjustment needed.
Moderate:
No specific adjustment needed.
Severe:
No specific adjustment needed.
Pharmacology
Mechanism of Action
Ampicillin is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and death. Sulbactam is a beta-lactamase inhibitor that irreversibly binds to and inactivates a wide range of bacterial beta-lactamases, protecting ampicillin from hydrolysis and extending its spectrum of activity against beta-lactamase-producing bacteria.
Pharmacokinetics
Absorption:
Bioavailability:
100% (IV administration)
Tmax:
Not applicable for IV; for IM, ~1 hour for both ampicillin and sulbactam.
FoodEffect:
Not applicable for parenteral administration.
Distribution:
Vd:
Ampicillin: 0.28-0.33 L/kg; Sulbactam: 0.24-0.27 L/kg. Widely distributed into most body tissues and fluids, including peritoneal fluid, blister fluid, and middle ear fluid. Limited penetration into CSF unless meninges are inflamed.
ProteinBinding:
Ampicillin: Approximately 28%; Sulbactam: Approximately 38%.
CnssPenetration:
Limited (unless meninges are inflamed)
Elimination:
HalfLife:
Ampicillin: Approximately 1-1.3 hours; Sulbactam: Approximately 1 hour (in patients with normal renal function).
Clearance:
Primarily renal clearance.
ExcretionRoute:
Primarily renal (glomerular filtration and tubular secretion).
Unchanged:
Ampicillin: 75-85%; Sulbactam: 75-85% (excreted unchanged in urine).
Pharmacodynamics
OnsetOfAction:
Rapid (within minutes of IV administration)
PeakEffect:
Within 1 hour of IV/IM administration
DurationOfAction:
Dependent on maintaining concentrations above the minimum inhibitory concentration (MIC), typically requiring dosing every 6-8 hours due to short half-life.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
In rare cases, allergic reactions can be fatal.
Diarrhea and Bowel Problems
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form of diarrhea called C. diff-associated diarrhea (CDAD) may occur. This condition can lead to life-threatening bowel problems. If you experience any of the following symptoms, contact your doctor right away:
Stomach pain
Cramps
Very loose, watery, or bloody stools
Do not treat diarrhea without consulting your doctor first.
Liver Problems
Liver problems have been reported rarely with this medication, and in some cases, have been fatal. If you notice any of the following symptoms, contact your doctor immediately:
Dark urine
Tiredness
Decreased appetite
Upset stomach or stomach pain
Light-colored stools
Vomiting
Yellow skin or eyes
Severe Skin Reactions
Severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions, may occur with this medication. These reactions can be life-threatening and may affect other organs. If you experience any of the following symptoms, seek medical help right away:
Red, swollen, blistered, or peeling skin
Red or irritated eyes
Sores in your mouth, throat, nose, eyes, genitals, or any areas of skin
Fever
Chills
Body aches
Shortness of breath
Swollen glands
Other Side Effects
Like all medications, this drug may cause side effects. Many people do not experience side effects or only have minor ones. If you are bothered by any of the following side effects or if they do not go away, contact your doctor:
Diarrhea
* Pain at the injection site (if given intramuscularly)
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
In rare cases, allergic reactions can be fatal.
Diarrhea and Bowel Problems
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form of diarrhea called C. diff-associated diarrhea (CDAD) may occur. This condition can lead to life-threatening bowel problems. If you experience any of the following symptoms, contact your doctor right away:
Stomach pain
Cramps
Very loose, watery, or bloody stools
Do not treat diarrhea without consulting your doctor first.
Liver Problems
Liver problems have been reported rarely with this medication, and in some cases, have been fatal. If you notice any of the following symptoms, contact your doctor immediately:
Dark urine
Tiredness
Decreased appetite
Upset stomach or stomach pain
Light-colored stools
Vomiting
Yellow skin or eyes
Severe Skin Reactions
Severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions, may occur with this medication. These reactions can be life-threatening and may affect other organs. If you experience any of the following symptoms, seek medical help right away:
Red, swollen, blistered, or peeling skin
Red or irritated eyes
Sores in your mouth, throat, nose, eyes, genitals, or any areas of skin
Fever
Chills
Body aches
Shortness of breath
Swollen glands
Other Side Effects
Like all medications, this drug may cause side effects. Many people do not experience side effects or only have minor ones. If you are bothered by any of the following side effects or if they do not go away, contact your doctor:
Diarrhea
* Pain at the injection site (if given intramuscularly)
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe or persistent diarrhea (especially watery or bloody, which could be a sign of C. difficile infection)
- New or worsening skin rash, hives, or itching
- Swelling of the face, lips, tongue, or throat
- Difficulty breathing or wheezing
- Unusual bruising or bleeding
- Yellowing of the skin or eyes (jaundice)
- Dark urine or pale stools
- Severe abdominal pain
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
If you are allergic to penicillin, as this may impact your ability to take this medication safely.
If you have been diagnosed with mononucleosis (mono), as this condition may affect how your body responds to the medication.
If you have experienced liver problems or jaundice (turned yellow) while taking this medication in the past, as this may indicate a sensitivity to the drug.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your existing health conditions and other drugs. Never start, stop, or adjust the dosage of any medication without first consulting your doctor to ensure your safety.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
If you are allergic to penicillin, as this may impact your ability to take this medication safely.
If you have been diagnosed with mononucleosis (mono), as this condition may affect how your body responds to the medication.
If you have experienced liver problems or jaundice (turned yellow) while taking this medication in the past, as this may indicate a sensitivity to the drug.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your existing health conditions and other drugs. Never start, stop, or adjust the dosage of any medication without first consulting your doctor to ensure your safety.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. This drug may interfere with certain laboratory tests, so be sure to notify your healthcare providers and lab personnel that you are taking it.
If you have diabetes and regularly test your urine for glucose, consult with your doctor to determine the most suitable tests to use, as this medication may affect the results.
Do not take this medication for a longer period than prescribed, as this may increase the risk of a second infection.
If you are pregnant, planning to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to ensure the best decision for you and your baby.
If you have diabetes and regularly test your urine for glucose, consult with your doctor to determine the most suitable tests to use, as this medication may affect the results.
Do not take this medication for a longer period than prescribed, as this may increase the risk of a second infection.
If you are pregnant, planning to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to ensure the best decision for you and your baby.
Overdose Information
Overdose Symptoms:
- Neurological symptoms (e.g., seizures, confusion, agitation), especially in patients with impaired renal function
- Gastrointestinal upset (nausea, vomiting, diarrhea)
What to Do:
Seek immediate medical attention or call a poison control center (1-800-222-1222). Treatment is largely supportive. Hemodialysis may be used to remove the drug from circulation in cases of severe overdose, especially in renally impaired patients.
Drug Interactions
Major Interactions
- Methotrexate (Ampicillin may decrease renal clearance of methotrexate, increasing its toxicity.)
- Warfarin (May enhance anticoagulant effect, monitor INR.)
Moderate Interactions
- Allopurinol (Increased incidence of skin rash with ampicillin.)
- Oral Contraceptives (May reduce efficacy of oral contraceptives; advise backup contraception.)
- Probenecid (Decreases renal tubular secretion of ampicillin and sulbactam, resulting in increased and prolonged plasma concentrations.)
- Tetracyclines (May antagonize the bactericidal effect of penicillins.)
Monitoring
Baseline Monitoring
Renal function (BUN, serum creatinine)
Rationale: To establish baseline and guide dose adjustment in renal impairment.
Timing: Prior to initiation of therapy.
Liver function tests (ALT, AST)
Rationale: Although rare, hepatic dysfunction has been reported.
Timing: Prior to initiation, especially in patients with pre-existing hepatic conditions.
Complete Blood Count (CBC) with differential
Rationale: To establish baseline, especially for prolonged therapy, due to potential for hematologic abnormalities.
Timing: Prior to initiation of therapy.
Routine Monitoring
Clinical response to therapy (e.g., fever, WBC count, resolution of infection signs/symptoms)
Frequency: Daily, or as clinically indicated.
Target: Resolution of infection.
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure, resistance, or superinfection.
Renal function (BUN, serum creatinine)
Frequency: Periodically, especially in patients with pre-existing renal impairment or on prolonged therapy.
Target: Within patient's baseline or acceptable limits.
Action Threshold: Significant increase warrants dose adjustment or discontinuation.
Signs of superinfection (e.g., new fever, persistent diarrhea, oral thrush)
Frequency: Daily throughout therapy and shortly after discontinuation.
Target: Absence of new infections.
Action Threshold: Presence of new symptoms requires investigation and appropriate management (e.g., C. difficile testing).
Symptom Monitoring
- Skin rash (maculopapular rash, urticaria)
- Diarrhea (especially severe or persistent, suggestive of C. difficile-associated diarrhea)
- Nausea/Vomiting
- Injection site reactions (pain, tenderness, phlebitis)
- Signs of allergic reaction (e.g., itching, swelling, difficulty breathing)
- Signs of liver dysfunction (e.g., jaundice, dark urine, abdominal pain)
- Signs of hematologic abnormalities (e.g., unusual bruising, bleeding, fatigue)
Special Patient Groups
Pregnancy
Category B. Studies in animals have shown no evidence of harm to the fetus. Adequate and well-controlled studies in pregnant women are lacking, but human experience with ampicillin has not shown evidence of adverse effects. Generally considered safe for use during pregnancy when clearly needed.
Trimester-Specific Risks:
First Trimester:
Low risk, no evidence of teratogenicity.
Second Trimester:
Low risk.
Third Trimester:
Low risk, but caution with use near term as penicillins may interfere with platelet aggregation.
Lactation
L2 (Safer). Both ampicillin and sulbactam are excreted in breast milk in low concentrations. Generally considered compatible with breastfeeding. Monitor breastfed infant for potential adverse effects such as diarrhea, candidiasis (thrush, diaper rash), or allergic sensitization (rash).
Infant Risk:
Low risk, but monitor for gastrointestinal disturbances (diarrhea, candidiasis) or allergic reactions (rash).
Pediatric Use
Dosing is established for infants, children, and adolescents. Neonatal dosing requires careful consideration due to immature renal function. Close monitoring for adverse effects is recommended.
Geriatric Use
Dose adjustment is primarily based on renal function, which often declines with age. Elderly patients are more likely to have impaired renal function, requiring careful dose titration and monitoring.
Clinical Information
Clinical Pearls
- Unasyn is a broad-spectrum antibiotic effective against many Gram-positive, Gram-negative, and anaerobic bacteria, particularly those producing beta-lactamase.
- It is commonly used for skin and soft tissue infections, intra-abdominal infections, gynecological infections, and community-acquired pneumonia.
- Administer IV doses slowly over 15-30 minutes to minimize injection site reactions.
- Reconstituted solutions should be used promptly; stability varies by diluent and concentration.
- Always inquire about penicillin allergies before administration, as cross-reactivity with other beta-lactams can occur.
Alternative Therapies
- Carbapenems (e.g., Meropenem, Imipenem/Cilastatin) for broader spectrum or resistant infections.
- Cephalosporins (e.g., Ceftriaxone, Cefotaxime) for susceptible infections.
- Fluoroquinolones (e.g., Levofloxacin, Moxifloxacin) for certain indications.
- Metronidazole (for anaerobic coverage, often combined with other agents).
Cost & Coverage
Average Cost:
Varies widely by formulation, strength, and supplier. Typically ranges from $10-$50 per 1.5g vial for generic. per 1.5g vial
Generic Available:
Yes
Insurance Coverage:
Generally covered by most insurance plans as a Tier 1 or Tier 2 generic medication.
General Drug Facts
If your symptoms or health problems persist or worsen, it is essential to contact your doctor for further guidance. To ensure safe use, never share your medication with others, and do not take medication prescribed for someone else. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion. Dispose of unused or expired medications properly; do not flush them down the toilet or pour them down the drain unless instructed to do so by a healthcare professional or pharmacist. If you are unsure about the correct disposal method, consult your pharmacist, who can also inform you about potential drug take-back programs in your area. Some medications may come with an additional patient information leaflet, which your pharmacist can provide. If you have any questions or concerns about your medication, discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide information about the medication taken, the amount, and the time it was taken to ensure prompt and effective treatment.