Generic Medicine Info
Indications and Dosage
Uncomplicated gonorrhoea
Adult: In combination with probenecid: 2.25 g as single dose.

Otitis media, Pyelonephritis, Respiratory tract infections, Skin and soft tissue infections, Urinary tract infections
Adult: 375-750 mg bid for 5-14 days; treatment duration may be extended if necessary. For group A β-haemolytic streptococcal infections, duration of treatment for at least 10 days is recommended.
Child: Dosage is individualised depending on the severity of the infection and clinical judgement. <30 kg: 25-50 mg/kg daily in 2 divided doses; ≥30 kg: Same as adult dose.
Renal Impairment
Respiratory tract infections; Otitis media; Urinary tract infections; Pyelonephritis; Skin and soft tissue infections:
CrCl (mL/min) Dosage
 ≤30 Less frequent dose administration may be required.
May be taken with or without food.
Hypersensitivity to ampicillin, sulbactam, or penicillins.
Special Precautions
Renal impairment. Children. Pregnancy and lactation.
Adverse Reactions
Significant: Severe skin reactions (e.g. Stevens-Johnson syndrome, toxic epidermal necrolysis, dermatitis exfoliative, erythema multiforme, acute exanthematous pustulosis); cholestatic hepatitis, jaundice; fungal or bacterial superinfection including Clostridium difficile-associated diarrhoea (CDAD) and pseudomembranous colitis (prolonged use).
Gastrointestinal disorders: Diarrhoea, nausea, vomiting, abdominal pain, melaena, stomatitis.
General disorders and administration site conditions: Fatigue, malaise.
Infections and infestations: Candida infection.
Investigations: Decreased plasma concentration of total conjugated estriol, estriol glucuronide, conjugated estrone, and estradiol (in pregnant women).
Musculoskeletal and connective tissue disorders: Arthralgia.
Nervous system disorders: Headache, dizziness.
Skin and subcutaneous tissue disorders: Pruritus, rash.
Potentially Fatal: Hypersensitivity reactions (e.g. anaphylaxis).
Monitoring Parameters
Monitor for signs of anaphylaxis during 1st dose. Monitor haematologic, renal, and hepatic function periodically during prolonged use. May perform culture and susceptibility tests prior to treatment initiation; consult local institutional recommendations before treatment initiation due to antibiotic resistance risks.
Drug Interactions
Increased incidence of rashes with allopurinol. May enhance the effect of anticoagulants. Bacteriostatic drugs (e.g. chloramphenicol, erythromycin, sulfonamides, tetracyclines) may interfere with the bactericidal effect of sultamicillin. Diminished therapeutic efficacy of estrogen-containing oral contraceptives. Decreased clearance of methotrexate thus increase toxicity. Increased and prolonged serum concentrations with probenecid.
Lab Interference
May cause false-positive glycosuria with urinary glucose tests using cupric sulfate (Benedict’s solution, Fehling reagent, Clinitest®).
Mechanism of Action: Sultamicillin is a prodrug of ampicillin and sulbactam linked as a double ester. Ampicillin prevents bacterial cell wall synthesis by binding to 1 or more of the penicillin-binding proteins resulting in inhibition of the final transpeptidation step of peptidoglycan synthesis in the bacterial cell walls. Sulbactam extends the spectrum of ampicillin activity due to its irreversible inhibition of β-lactamases that are found in penicillin-resistant organisms. It has limited antibacterial activity to Neisseriaceae.
Absorption: Absorbed from the gastrointestinal tract. Bioavailability: 80%.
Distribution: Crosses the placenta, enters breast milk (small amounts). Distributed in the bile, blister, and tissue fluids; penetrates the CSF with inflamed meninges only. Plasma protein binding: 28% (ampicillin); 38% (sulbactam).
Metabolism: Metabolised via hydrolysis to provide a 1:1 molar ratio of ampicillin and sulbactam.
Excretion: Via urine (50-75% as unchanged drug). Elimination half-life: Approx 0.75 hour (sulbactam); 1 hour (ampicillin).
Chemical Structure

Chemical Structure Image

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 444022, Sultamicillin. Accessed Jan. 26, 2021.

Store below 30°C. Reconstituted oral suspension must be stored in the refrigerator and used within 14 days.
MIMS Class
ATC Classification
J01CR04 - sultamicillin ; Belongs to the class of penicillin combinations, including beta-lactamase inhibitors. Used in the systemic treatment of infections.
Anon. Sultamicillin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. Accessed 15/12/2020.

Buckingham R (ed). Sultamicillin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. Accessed 15/12/2020.

Unasyn Oral (Pfizer Global Supply Japan Inc. Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. Accessed 15/12/2020.

Zunamyn Film-Coated Tablet (Lloyd Laboratories, Inc.). MIMS Philippines. Accessed 15/01/2021.

Disclaimer: This information is independently developed by MIMS based on Sultamicillin from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2024 MIMS. All rights reserved. Powered by
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