Unictam (Ampicillin/Sulbactam): Uses, Formulations, and Administration

1. Disclaimer

The information provided in this document is intended solely for educational and professional reference purposes and does not constitute medical advice, diagnosis, or treatment. Clinical decisions must always be based on the approved prescribing information issued by relevant regulatory authorities and the professional judgment of qualified healthcare professionals.

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2. Summary

Unictam® is a combination antibacterial agent containing ampicillin and sulbactam, classified as a penicillin with a beta-lactamase inhibitor. The combination broadens ampicillin’s activity against beta-lactamase–producing organisms and is used in a variety of community-acquired and hospital-acquired infections. Unictam is available in parenteral and oral formulations, allowing both initial and step-down therapy.

3. Brand Name

Unictam®

4. Category

• Antibacterial agents
• Beta-lactam antibiotics
• Penicillins combined with beta-lactamase inhibitors

5. Active Ingredient

Parenteral forms (IM/IV): Ampicillin sodium + Sulbactam sodium

Oral forms (tablets and suspension): Sultamicillin (a mutual prodrug that is hydrolyzed after absorption into ampicillin and sulbactam)

6. Pharmaceutical Form & Strength

Injectable powder for IM/IV use:

• 375 mg vial (250 mg ampicillin + 125 mg sulbactam)
• 750 mg vial (500 mg ampicillin + 250 mg sulbactam)
• 1.5 g vial (1 g ampicillin + 0.5 g sulbactam)
• 3 g vial (2 g ampicillin + 1 g sulbactam)

Oral forms:

• Tablets: 375 mg, 750 mg
• Powder for oral suspension: 250 mg/5 mL (60 mL bottle)

(All strengths reflect an approximate 2:1 ratio of ampicillin to sulbactam after conversion.)

7. Manufacturer & Marketing Authorization Holder

Medical Union Pharmaceuticals (MUP) Egypt

8. Mechanism of Action

• Ampicillin inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), resulting in bactericidal activity.
• Sulbactam irreversibly inhibits many beta-lactamase enzymes, protecting ampicillin from enzymatic degradation and restoring activity against resistant strains.
• Sulbactam itself has minimal intrinsic antibacterial activity.

9. Spectrum of Activity

Active against susceptible strains of:

Gram-positive bacteria:

• Streptococcus spp., Enterococcus faecalis, methicillin-susceptible Staphylococcus aureus (MSSA)

Gram-negative bacteria:

• Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella spp., Proteus mirabilis, Neisseria spp., Acinetobacter spp. (some strains)

Anaerobes:

• Bacteroides fragilis group, Peptostreptococcus spp., Clostridium spp. (excluding C. difficile)

Not active against: MRSA, Pseudomonas aeruginosa, ESBL-producing Enterobacterales, VRE.

10. Pharmacokinetics

Absorption:

• IM/IV: Complete systemic availability
• Oral (sultamicillin): Better bioavailability than ampicillin alone; absorption may be reduced by food

Distribution: Widely distributed into tissues and body fluids; limited CSF penetration unless meninges are inflamed

Protein binding: Low to moderate

Metabolism: Minimal hepatic metabolism

Elimination: Primarily renal excretion as unchanged drug

Half-life: Approximately 1 hour (prolonged in renal impairment)

11. Indications

Treatment of infections caused by susceptible organisms, including:

• Upper and lower respiratory tract infections
• Urinary tract infections
• Skin and soft tissue infections (including bites)
• Intra-abdominal infections
• Gynecological infections
• Bone and joint infections
• Septicemia
• Surgical prophylaxis (selected procedures)

12. Administration

• IV: Slow injection or infusion
• IM: Deep intramuscular injection
• Oral: Tablets or suspension for mild infections or step-down therapy

Dosage and duration depend on infection severity, organism susceptibility, patient age, weight, and renal function.

13. Method of Preparation

• Injectable vials: Reconstitute with sterile water for injection or compatible IV fluids; lidocaine 0.5–1% may be used for IM injection (if not contraindicated).
• Oral suspension: Add the specified volume of water, shake well, and shake before each dose.

14. Contraindications

• Hypersensitivity to ampicillin, sulbactam, penicillins, or other beta-lactam antibiotics
• History of severe immediate allergic reactions (e.g. anaphylaxis) to beta-lactams
• Infectious mononucleosis (due to high incidence of rash)

15. Warnings & Precautions

• Risk of serious hypersensitivity reactions
• Possible Clostridioides difficile–associated diarrhea
• Prolonged use may cause superinfection
• Dose adjustment required in renal impairment
• Monitor renal, hepatic, and hematologic parameters during prolonged therapy
• Injectable forms contain sodium; use caution in sodium-restricted patients

16. Drug Interactions

• Probenecid: Increases serum levels
• Allopurinol: Increased risk of rash
• Methotrexate: Reduced clearance and increased toxicity
• Oral anticoagulants: Possible enhancement of anticoagulant effect
• Oral contraceptives: Possible reduction in efficacy
• Aminoglycosides: Do not mix in the same IV solution

17. Side Effects

Common:

• Diarrhea, nausea, vomiting, rash, injection-site pain

Uncommon:

• Elevated liver enzymes, candidiasis, headache

Rare but serious:

• Anaphylaxis, Stevens–Johnson syndrome, toxic epidermal necrolysis, seizures (high doses or renal failure), hematologic abnormalities

18. Use in Special Populations

• Pregnancy: Category B; use if clearly needed
• Lactation: Excreted in breast milk in small amounts; generally compatible
• Pediatrics: Weight-based dosing required
• Elderly: Assess renal function regularly
• Renal impairment: Dose and/or interval adjustment required

19. Storage Conditions

• Store below 25–30°C, protected from moisture and light
• Reconstituted injectable solutions should be used promptly
• Reconstituted oral suspension should be refrigerated and discarded after 14 days

20. Additional Sections

Antimicrobial Stewardship:

Unictam should be reserved for infections where beta-lactamase–producing organisms are suspected or confirmed, and therapy should be de-escalated based on culture results.

21. Frequently Asked Questions (FAQ)

Is Unictam the same as Unasyn? Yes. Both contain ampicillin/sulbactam; Unictam is a regional brand.

Does it treat viral infections? No. It is effective only against bacterial infections.

Can oral and injectable forms be switched? Yes, when clinically appropriate and with correct dose adjustment.

22. References

1. Official prescribing information for ampicillin/sulbactam (Unasyn®)
2. Lexicomp® Drug Database (2024–2025)
3. Micromedex® Solutions
4. Sanford Guide to Antimicrobial Therapy (2024)
5. UpToDate®: Ampicillin–Sulbactam
6. British National Formulary (BNF)