Chemical formula: C₁₃H₁₇N₅O₈S₂  Molecular mass: 435.433 g/mol  PubChem compound: 5742832


Aztreonam interacts in the following cases:

Severe renal failure

Prolonged serum levels of aztreonam may occur in patients with transient or persistent renal insufficiency. Therefore, after an initial usual dose, the dosage of aztreonam should be halved in patients with estimated creatinine clearances between 10 and 30 mL/min/1.73 m².

In patients with severe renal failure (creatinine clearance less than 10 mL/min/1.73 m²), such as those supported by hemodialysis, the usual dose should be given initially. The maintenance dose should be one-fourth of the usual initial dose given at the usual fixed interval of 6, 8 or 12 hours. For serious or life-threatening infections, in addition to the maintenance doses, one-eighth of the initial dose should be given after each hemodialysis session.

Oral anticoagulants

Prolongation of prothrombin time has been reported rarely in patients receiving aztreonam. Additionally, numerous cases of increased activity of oral anticoagulants have been reported in patients receiving antibiotics, including beta-lactams. Severe infection or inflammation, and the age and general condition of the patient appear to be risk factors. Appropriate monitoring should be undertaken when anticoagulants are prescribed concomitantly. Adjustments in the dose of oral anticoagulants may be necessary to maintain the desired level of anticoagulation.


If an aminoglycoside is used concurrently with aztreonam, especially if high dosages of the former are used or if therapy is prolonged, renal function should be monitored because of the potential nephrotoxicity and ototoxicity of aminoglycoside antibiotics.

Probenecid, furosemide

Concomitant administration of probenecid or furosemide and aztreonam cause clinically insignificant increases in the serum levels of aztreonam.

Chronic liver disease with cirrhosis

A dose reduction of 20-25% is recommended for long-term treatment of patients with chronic liver disease with cirrhosis, especially in cases of alcoholic cirrhosis and when renal function is also impaired.


Respiratory administration

There are no data from the use of aztreonam in pregnant women. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity.

Systemic concentration of aztreonam following inhaled administration of aztreonam is low compared to a standard dose of aztreonam for injection (approximately 1% of the concentration resulting from a dose of 500 mg aztreonam for injection).

Aztreonam should not be used during pregnancy unless the clinical condition of the woman requires treatment with aztreonam.

IV / IM administration

Aztreonam is contraindicated in pregnancy. Aztreonam crosses the placenta and enters the foetal circulation.

There are no adequate and well-controlled studies in pregnant women. Studies in pregnant rats and rabbits, with daily doses up to 15 and 5 times the maximum recommended human dose respectively, revealed no evidence of embryo- or fetotoxicity or teratogenicity. Because animal reproduction studies are not always predictive of human response, aztreonam should be used during pregnancy only if clearly needed.

Nursing mothers

Respiratory administration

Following administration of aztreonam for injection, aztreonam is excreted in human milk at very low concentrations. Systemic concentration of aztreonam following inhaled administration of aztreonam is approximately 1% of the concentration resulting from a standard dose of aztreonam for injection. Therefore, and because of low oral absorption, aztreonam exposure in breast-fed infants due to mothers receiving aztreonam is likely to be extremely low.

IV / IM administration

Aztreonam is excreted in breast milk in concentrations that are less than 1% of those in simultaneously obtained maternal serum. Lactating mothers should refrain from breast feeding during the course of therapy.

Carcinogenesis, mutagenesis and fertility


Non-clinical data for aztreonam for injection about fertility do not indicate any adverse effects.

Effects on ability to drive and use machines

Respiratory administration

Aztreonam has no or negligible influence on the ability to drive or use machines.

IV / IM administration

Aztreonam can have an important impact on the ability to drive and use of machines should encephalopathy occur.

Adverse reactions

Respiratory administration

Summary of the safety profile

Assessment of adverse reactions is based on experience in four Phase 3 clinical studies involving CF patients with chronic P. aeruginosa infection and post-marketing spontaneous reporting.

In the two Phase 3 placebo-controlled clinical studies where patients received aztreonam for 28 days, the most frequently occurring adverse reactions to aztreonam were cough (58%), nasal congestion (18%), wheezing (15%), pharyngolaryngeal pain (13.0%), pyrexia (12%) and dyspnoea (10%).

An acute reduction of ≥15% in FEV1 is a complication associated with nebulised therapies, including aztreonam.

Tabulated summary of adverse reactions

The adverse reactions considered at least possibly related to treatment from clinical study and post-marketing experience are listed below by body system organ class and frequency.

Frequencies are defined as follows: very common (≥1/10), common (≥1/100 to <1/10) and uncommon (≥1/1000 to <1/100).

Respiratory, thoracic and mediastinal disorders:
Very common: cough, nasal congestion, wheezing, pharyngolaryngeal pain, dyspnoea
Common: bronchospasm1, chest discomfort, rhinorrhoea, haemoptysis1
Skin and subcutaneous tissue disorders:
Common: rash1
Musculoskeletal and connective tissue disorders:
Common: arthralgia
Uncommon: joint swelling
General disorders and administration site conditions:
Very common: pyrexia
Common: lung function test decreased1

1 See section Description of selected adverse reactions.

Description of selected adverse reactions


Nebulised therapies, including aztreonam, may be associated with bronchospasm (an acute reduction of ≥15% in FEV1). Refer to section 4.4.


Inhalation of nebulised solutions may induce a cough reflex which could aggravate underlying conditions.

Allergic reactions

Rash has been reported with the use of aztreonam and may be indicative of an allergic reaction to aztreonam.

Lung function test decreased

Lung function test decreased has been reported with use of aztreonam, but was not associated with a sustained decrease in FEV1.

The following rare and severe adverse reactions have been reported after parenteral use of other aztreonam containing products: toxic epidermal necrolysis, anaphylaxis, purpura, erythema multiforme, exfoliative dermatitis, urticaria, petechiae, pruritus, diaphoresis.

Paediatric population

A total of 137 paediatric patients aged 6 to 17 years with chronic P. aeruginosa infection and FEV1 ≤75% predicted have received aztreonam in Phase 2 and Phase 3 clinical studies (6-12 years, n=35; 13-17 years, n=102).

Pyrexia was observed at a higher incidence rate in paediatric patients aged 6 to 17 years compared to adults.

IV / IM administration

The list of undesirable effects shown below is presented by system organ class, MedDRA preferred term, and frequency. Very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1000 to <1/100); rare (≥1/10,000 to <1/1000); very rare (≥1/10,000); Not known (cannot be estimated from the available data).

System Organ Class Frequency MedDRA Term
Blood and lymphatic system disorders Rare Pancytopenia, thrombocytopenia,
thrombocythaemias, leukocytosis, neutropenia,
eosinophilia, anaemia, prothrombin time
prolonged, activated partial thromboplastin time
prolonged, Coombs test positive
Ear and labyrinth disorders Rare Vertigo, tinnitus
Eye disorders Rare Diplopia
Gastrointestinal disorders RareGastro intestinal haemorrhage,
pseudomembranous colitis, breath odour
Not knownAbdominal pains, mouth ulceration, nausea,
vomiting, diarrhoea, altered taste
General disorders and administration site
RareChest pain, pyrexia, asthenia, malaise
Not knownInjection site discomfort, weakness, sweating,
muscle aches, fever, transient increases in
serum creatinine
Hepato-biliary disorders RareHepatitis, jaundice
Not knownTransaminases increased*, blood alkaline
phosphatase increased*
Infections and infestations Rare Vaginitis, vaginal candidiasis
Immune system disorders Not known Anaphylactic reaction
Investigations Rare Electrocardiogram change
Musculoskeletal, connective tissue and
bone disorders
Rare Myalgia
Nervous system disorders RareConvulsions, paraesthesia, dizziness,
Not knownDysgeusia
Encephalopathy (confusional state, altered
state of consciousness, epilepsy, movement
Psychiatric disorders Rare Confusional state, insomnia
Renal and urinary disorders Uncommon Blood creatinine increased
Reproductive system and breast
Rare Breast tenderness
Respiratory, thoracic and mediastinal
RareWheezing, dyspnoea, sneezing, nasal
Not knownBronchospasm
Skin and subcutaneous tissue disorders Not known Toxic epidermal necrolysis, angioedema,
erythema multiforme, dermatitis exfoliative,
hyperhidrosis, petechiae, purpura, urticaria,
rash, pruritus
Vascular disorders RareHypotension, haemorrhage
Not knownPhlebitis, thrombophlebitis, flushing

* Usually reversing during therapy and without overt signs or symptoms of hepatobiliary dysfunction.

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