aztreonam

IM:

REMS

IV: Treatment of serious gram-negative infections including:
- Septicemia,
- Skin and skin structure infections,
- Intra-abdominal infections,
- Gynecologic infections,
- Respiratory tract infections,
- Urinary tract infections.
Useful for treatment of multiresistant strains of some bacteria including aerobic gram-negative pathogens.
Inhaln: To improve respiratory symptoms in cystic fibrosis (CF) patients with
Pseudomonas aeruginosa
.

Action ⬆ ⬇

Binds to the bacterial cell wall membrane, causing cell death.

Therapeutic effects:

Bactericidal action against susceptible bacteria.

Spectrum:

Displays significant activity against gram-negative aerobic organisms only:
- Escherichia coli,
- Serratia,
- Klebsiella oxytoca or pneumoniae,
- Citrobacter,
- Proteus mirabilis,
- Pseudomonas aeruginosa,
- Enterobacter,
- Haemophilus influenzae.
Not active against:
- Staphylococcus aureus,
- Enterococcus,
- Bacteroides fragilis,
- Streptococci.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed following IM administration. IV administration results in complete bioavailability. Low absorption follows administration by oral inhalation.

Distribution: Widely distributed to tissues. High concentrations achieved in sputum with inhalation.

Metabolism/Excretion: 60–70% excreted unchanged by the kidneys. 10% of inhaled dose excreted unchanged in urine. Small amounts metabolized by the liver.

Half-Life: Adults: 1.5–2 hr; Children: 1.7 hr; Neonates: 2.4–9 hr (↑ in renal impairment).

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
IM	rapid	60 min	6–8 hr
IV	rapid	end of infusion	6–8 hr
Inhaln	rapid	unknown	Several hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Lactation: Lactation (IV/IM formulation).

Use Cautiously in:

Renal impairment (dosage ↓ required if CCr 30 mL/min or less);
Cross-sensitivity with penicillins or cephalosporins may occur rarely. Has been used safely in patients with a history of penicillin or cephalosporin allergy;
Patients with FEV₁<25% or >75% predicted, or patients colonized with
Burkholderia cepacia
(safety and effectiveness not established);
OB: Safety of IV/IM formulation not established in pregnancy. Systemic absorption of oral inhalation expected to be minimal;
Lactation: Systemic absorption of oral inhalation expected to be minimal;
Pedi: Children 7 yr (oral inhalation) (safety and effectiveness not established);
Geri: Consider age-related in renal function in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: chest discomfort (oral inhalation)

Derm: rash

EENT: nasal congestion (oral inhalation), nasopharyngeal pain (oral inhalation)

GI: abdominal pain (oral inhalation), altered taste, CLOSTRIDIOIDES DIFFICILE-ASSOCIATED DIARRHEA (CDAD), diarrhea, nausea, vomiting

Local: pain at IM site, phlebitis at IV site

Neuro: SEIZURES

Resp: cough (oral inhalation), wheezing (oral inhalation), bronchospasm (oral inhalation)

Misc: fever (inhalation), HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS) , superinfection

Interactions ⬆ ⬇

Drug-drug:

Levels may be ↑ by furosemide or probenecid.

Route/Dosage ⬆ ⬇

IM IV (Adults ): Moderately severe infections: 1–2 g every 8–12 hr; severe or life-threatening infections (including those due to Pseudomonas aeruginosa): 2 g every 6–8 hr; urinary tract infections: 0.5–1 g every 8–12 hr.
IV (Children 1 mo–16 yr): Mild to moderate infections: 30 mg/kg every 8 hr; moderate to severe infections: 30 mg/kg every 6–8 hr; cystic fibrosis: 50 mg/kg every 6–8 hr.
IV (Neonates >2 kg): 30 mg/kg every 6–8 hr.
IV (Neonates ≤2 kg): 30 mg/kg every 8–12 hr.
Inhaln
(Adults and Children >7 yr): 75 mg three times daily for 28 days.

Renal Impairment

IV (Adults ): CCr 10–30 mL/min: 1–2 g initially, then 50% of usual dosage at usual interval; CCr <10 mL/min: 500 mg–2 g initially, then 25% of usual dosage at usual interval (⅛ of initial dose should also be given after each hemodialysis session).

Availability ⬆ ⬇

(Generic available)

Powder for injection: 1 g/vial; 2 g/vial
Lyophilized powder for use with diluent provided in Altera Nebulizer System only (Cayston): 75 mg/vial with 1 mL ampule of diluent (0.17% sodium chloride)

Assessment ⬆ ⬇

Assess for infection (vital signs; wound appearance, sputum, urine, and stool; WBC) at beginning of and throughout therapy.
Obtain a history before initiating therapy to determine previous use of and reactions to penicillins and cephalosporins. Patients allergic to these drugs may exhibit hypersensitivity reactions to aztreonam. However, aztreonam can often be used in these patients.
Obtain specimens for culture and sensitivity before initiating therapy. First dose may be given before receiving results.
Assess respiratory status prior to and following inhalation therapy.
Observe for signs and symptoms of anaphylaxis (rash, pruritus, laryngeal edema, wheezing). Notify the health care professional immediately if these occur.
Monitor bowel function. Report diarrhea, abdominal cramping, fever, and bloody stools to health care professional promptly as a sign of CDAD. May begin up to several wk following cessation of therapy.

Lab Test Considerations:

May cause ↑ in AST, ALT, alkaline phosphatase, LDH, and serum creatinine. May cause ↑ prothrombin and partial thromboplastin times, and positive Coombs’ test.

Implementation ⬆ ⬇

After adding diluent to vial, shake immediately and vigorously. Not for multidose use; discard unused solution. IV route is recommended if single dose >1 g or for severe or life-threatening infection.
IM: Dilute each gram of aztreonam with at least 3 mL of 0.9% NaCl, or sterile or bacteriostatic water for injection. Stable at room temperature for 48 hr or 7 days if refrigerated.
- Administer into large, well-developed muscle.
Inhaln: Open glass aztreonam vial by removing metal ring and pulling tab, and removing gray rubber stopper. Twist tip of diluent ampule and squeeze contents into glass aztreonam vial. Replace rubber stopper and swirl gently until contents are completely dissolved. Administer immediately after reconstitution using Altera Nebulizer System. Pour reconstituted solution into handset of nebulizer. Turn unit on. Place mouthpiece into mouth and breathe normally only through mouth. Administration takes 2–3 min. Do not use other nebulizers or mix with other medications. Do not administer IV or IM. Refrigerate aztreonam and diluent; may be stored at room temperature for up to 28 days. Protect from light.
- Administer short-acting bronchodilator between 15 min and 4 hr or long-acting bronchodilator between 30 min and 12 hr prior to treatment. If taking multiple inhaled therapies, administer in the following order: bronchodilator, mucolytic, and lastly, aztreonam.

IV Administration:

Reconstitute each vial with 6–10 mL of sterile water for injection.
Rate: Administer slowly over 3–5 min by direct injection or into tubing of a compatible solution.
Intermittent Infusion: Reconstitute each vial with 3 mL of sterile water for injection. Diluent: Dilute further with 0.9% NaCl, Ringer’s or LR, D5W, D10W, D5/0.9% NaCl, D5/0.45% NaCl, D5/0.2% NaCl, D5/LR, or sodium lactate.Concentration: Do not exceed 50 mg/mL. Solution is stable for 48 hr at room temperature and 7 days if refrigerated. Solutions range from colorless to light, straw yellow or may develop a pink tint upon standing; this does not affect potency.
Rate: Infuse over 20–60 min.

Patient/Family Teaching ⬆ ⬇

Advise patient to report the signs of superinfection (furry overgrowth on the tongue, vaginal itching or discharge, loose or foul-smelling stools) and allergy.
Instruct patient to notify health care professional if fever and diarrhea develop, especially if stool contains blood, pus, or mucus. Advise patient not to treat diarrhea without consulting health care professional.
Advise patient to notify health care professional if new or worsening symptoms occur or if signs or symptoms of anaphylaxis occur.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding. Patients receiving IV aztreonam should consider temporarily discontinuing breastfeeding or using formula during therapy.
Inhaln: Instruct patient to use aztreonam as directed for the full 28-day course, even if feeling better. If a dose is missed, take all 3 daily doses, as long as doses are at least 4 hr apart. Skipping doses or not completing full course of therapy may decrease effectiveness and increase likelihood of bacterial resistance not treatable in the future. Inform patient of the importance of using a bronchodilator prior to treatment and in use and cleaning of nebulizer. Advise patient to read Patient Information before starting therapy.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇