Amikacin Liposome

Introduction Overview

Generic Name

amikacin liposome

Brand Name

Arikayce

Dosage Form

Suspension, Liposomal, Inhalation (590 mg/8.4 mL)

Drug Class

Aminoglycosides

Pharmacokinetics

Absorption

Arikayce is administered via inhalation as a liposomal suspension directly into the lungs using the Lamira Nebulizer System. This localized delivery targets pulmonary tissues, allowing high local concentrations in the lungs with minimal systemic absorption. Studies demonstrate measurable systemic absorption of amikacin after inhalation, but plasma concentrations remain significantly lower than those achieved by intravenous administration, minimizing systemic toxicity. Systemic absorption is variable and may be influenced by lung pathology and drug dose administered. Absorption via the respiratory mucosa occurs gradually as the liposome-encapsulated amikacin is released into lung tissue, prolonging drug presence and facilitating bactericidal activity against intracellular organisms within alveolar macrophages.

Distribution

Once inhaled, amikacin liposome distributes primarily within the pulmonary alveoli and bronchial spaces where Mycobacterium avium complex (MAC) infections reside. The liposomal encapsulation facilitates penetration of amikacin into macrophages, which are common reservoirs for MAC bacteria, enhancing intracellular delivery. Systemically absorbed amikacin distributes widely throughout body tissues and fluids, exhibiting poor penetration into the central nervous system under non-inflamed conditions. Aminoglycosides, including amikacin, bind minimally to plasma proteins, resulting in a high free drug fraction. Volume of distribution for inhaled amikacin is lower than intravenous formulations, reflecting predominately localized lung tissue distribution.

Metabolism

Amikacin, including its liposomal formulation in Arikayce, is not significantly metabolized by hepatic enzymes. The drug is primarily eliminated unchanged. There is no evidence of hepatic transformation or biotransformation of amikacin liposome complexes. This lack of metabolism reduces the risk of hepatic drug-drug interactions and metabolic variability. The encapsulation in liposomes may modulate release rate and duration of exposure locally in the lungs but does not impact systemic metabolic processes.

Elimination

Elimination of amikacin occurs predominantly via renal excretion of unchanged drug through glomerular filtration. Because of the inhaled route, systemic exposure is relatively low, yet absorbed amikacin undergoes renal clearance consistent with systemic aminoglycosides. The half-life of systemically absorbed amikacin is approximately 2 to 3 hours in patients with normal renal function but may be prolonged in renal impairment. The liposomal formulation allows a sustained release of amikacin in the lungs, prolonging residence time. Careful monitoring of renal function is essential during therapy to avoid nephrotoxicity. Clearance may be affected by co-administration of other nephrotoxic agents.

Dosage Forms

Adults

Arikayce is supplied as a liposomal suspension for inhalation formulated as 590 mg amikacin per 8.4 mL vial. The recommended dose in adults for treatment of MAC lung disease is 590 mg once daily administered via the Lamira Nebulizer System. Treatment is part of a combination antibacterial regimen. Prior to inhalation, the vial should be at room temperature, shaken for 10 to 15 seconds, and the contents delivered completely via nebulizer. The therapy is intended for adults with limited or no alternative treatment options and who have not achieved sputum culture negativity after at least 6 months of background regimen therapy.

Adolescents

Arikayce's safety and efficacy have not been established in pediatric patients or adolescents younger than 18 years of age. Use in this population is not recommended due to lack of supporting clinical data and formulation considerations.

Special Populations

In patients with lung diseases such as bronchiectasis, COPD, and asthma, bronchospasm is a known risk; therefore, pre-treatment with short-acting beta-2 agonists or bronchodilators should be considered to reduce airway hyperreactivity before inhalation of Arikayce. Caution is recommended in patients with hearing impairment or renal insufficiency due to systemic absorption leading to ototoxicity and nephrotoxicity risks. Pregnant women should only use Arikayce if the potential benefit justifies the potential risk to the fetus, as systemic aminoglycosides are known to cause fetal harm, including congenital deafness. Breastfeeding mothers should consult healthcare providers; the safety of Arikayce during lactation is unknown. No dose adjustments are specified for renal or hepatic impairment, but monitoring is advised.

Mechanism Of Action

Arikayce contains amikacin sulfate encapsulated in liposomes, designed for inhalational delivery targeting pulmonary infections caused by Mycobacterium avium complex (MAC). Amikacin is an aminoglycoside antibiotic that exerts bactericidal activity by binding irreversibly to the 30S ribosomal subunit of susceptible bacteria. This interaction interferes with the initiation complex of peptide formation, causes misreading of messenger RNA, and ultimately inhibits bacterial protein synthesis, leading to cell death.

The liposomal formulation encapsulates amikacin in phospholipid vesicles, enabling targeted delivery to lung tissues and alveolar macrophages, which serve as reservoirs for intracellular MAC. This encapsulation prolongs residence time in the pulmonary environment, facilitates uptake by infected cells, and maintains sustained drug release, thereby optimizing intracellular antibacterial concentrations while limiting systemic exposure and toxicity.

Clinically, the liposomal inhaled delivery of amikacin allows high local antimicrobial activity directly at the infection site within the lung parenchyma and airways. The enhanced intracellular delivery improves eradication of mycobacteria residing within macrophages, overcoming limitations of systemic aminoglycosides, which poorly penetrate intracellular compartments. This mechanism supports the use of Arikayce in combination antibacterial regimens for difficult-to-treat MAC lung disease.

Comparatively, Arikayce’s inhaled liposomal delivery differs from traditional systemic aminoglycoside delivery by maximizing pulmonary drug concentrations and minimizing systemic adverse effects such as nephrotoxicity and ototoxicity. Clinical studies have demonstrated microbiological response in patients with refractory MAC lung disease, supporting the mechanistic rationale of enhanced delivery and intracellular targeting inherent to Arikayce's formulation.

Pharmacological Actions

Bactericidal activity against Mycobacterium avium complex (MAC) by inhibiting bacterial protein synthesis
Enhanced intracellular delivery of amikacin to alveolar macrophages via liposomal encapsulation
Sustained release of amikacin in pulmonary tissues allowing prolonged antimicrobial effect
Localized antibiotic action in the lungs with reduced systemic absorption and toxicity
Combination use with other antibacterial agents to treat refractory MAC lung disease
Inhaled delivery reduces systemic side effects commonly seen with intravenous aminoglycosides
Disruption of bacterial cell wall synthesis indirectly through inhibition of protein synthesis leading to bacterial cell death
Reduction of bacterial load in difficult-to-treat pulmonary infections caused by MAC

Therapeutic Clinical Uses

Treatment of Mycobacterium avium complex (MAC) lung disease in adult patients with limited or no alternative treatment options
Used in patients who have not achieved negative sputum cultures after a minimum of 6 months of multidrug background regimen therapy
Administered as part of combination antibacterial drug regimens for refractory pulmonary MAC infections
Targeted therapy for difficult-to-treat nontuberculous mycobacterial lung infections with intracellular bacterial involvement
Utilized when conventional treatment approaches are ineffective or contraindicated

Side Or Adverse Effects

Life-threatening allergic reactions including coughing, wheezing, hives, facial or throat swelling
Allergic inflammation of the lungs presenting with fever, cough, wheezing, and shortness of breath
Coughing up blood (hemoptysis) as a serious common adverse event
Severe bronchospasm causing shortness of breath, chest tightness, wheezing, and cough
Worsening of chronic obstructive pulmonary disease (COPD) symptoms
Ototoxicity signs including ringing in the ears, hearing loss, dizziness, vertigo
Common respiratory symptoms such as cough, increased mucus production, sore throat, and hoarseness
Nausea, vomiting, diarrhea, and gastrointestinal discomfort
Fever, headache, muscle pain, and chest discomfort
Skin rash and allergic dermatologic reactions
Weight loss and general fatigue or tiredness
Kidney impairment manifesting as decreased urine output, swelling, and fatigue

Precautions

Avoid use in patients with known hypersensitivity to amikacin or other aminoglycosides
Monitor patients with pre-existing lung disorders such as asthma, COPD, or bronchiectasis closely for bronchospasm
Assess auditory function before and during treatment especially in those with history of hearing impairment
Renal function should be checked prior to and during treatment to detect potential nephrotoxicity
Consider pre-treatment with bronchodilators for patients at risk of airway hyperreactivity
Use cautiously in patients with neuromuscular disorders like myasthenia gravis due to risk of muscle weakness
Pregnant patients should be counseled on potential fetal risks and alternative therapies evaluated
Breastfeeding mothers should be informed of possible drug secretion in milk and advised accordingly
Avoid concurrent nephrotoxic or ototoxic drugs to reduce additive toxicity
Patients should be instructed on correct nebulizer technique and adherence to dosing schedule
Advise patients to discard leftover medication after single use to prevent contamination
Monitor for signs of allergic or hypersensitivity reactions and discontinue drug if they occur
Avoid exposing vials to freezing temperatures and store properly to maintain drug stability

Warnings

Serious and potentially life-threatening allergic reactions may occur requiring immediate medical intervention
Bronchospasm and severe respiratory distress are common and may necessitate stopping therapy
Risk of hemoptysis (coughing up blood) which may lead to significant respiratory compromise
Potential for worsening of symptoms in patients with underlying COPD
Ototoxicity presenting as tinnitus, hearing loss, dizziness, or vertigo has been reported and can be irreversible
Nephrotoxicity risk necessitates close monitoring of renal function
Use with caution in patients with neuromuscular disorders as aminoglycosides can exacerbate muscle weakness
Pregnancy may pose risk of fetal harm; use only if benefits outweigh risks
Not recommended for pediatric use due to lack of established safety and efficacy
Do not use in patients with allergy to aminoglycosides including gentamicin, kanamycin, tobramycin, neomycin, paromomycin, or streptomycin
Increased risk of adverse effects when combined with other nephrotoxic or ototoxic agents

Contraindications

Known hypersensitivity or allergy to amikacin or other aminoglycoside antibiotics
History of severe allergic reactions to gentamicin, kanamycin, neomycin, paromomycin, streptomycin, or tobramycin
Patients with active bronchospasm not adequately controlled prior to dosing
Pediatric patients below 18 years of age due to unestablished safety
Incompatible with concurrent use of drugs with known additive nephrotoxicity or ototoxicity unless under strict monitoring
Patients with severe renal impairment when benefit does not outweigh risk

Drug Interactions

Concurrent use with other nephrotoxic drugs (e.g., amphotericin B, cisplatin, vancomycin, loop diuretics) increases risk of kidney damage
Use with other ototoxic agents can exacerbate hearing loss or vestibular dysfunction
Co-administration with neuromuscular blocking agents may potentiate respiratory paralysis
Use with potent diuretics like furosemide requires caution due to enhanced aminoglycoside toxicity
Drugs prolonging QT interval should be used with caution due to potential additive cardiac effects
Nonsteroidal anti-inflammatory drugs (NSAIDs) may increase nephrotoxicity risk when combined with amikacin
Concurrent use of other inhaled antibiotics requires monitoring for cumulative pulmonary adverse effects
Herbal supplements and over-the-counter medications should be reviewed for potential interactions
Combination with systemic aminoglycosides generally not recommended due to overlapping toxicity profiles

Preparations Of The Drug

Arikayce is available as a liposomal suspension inhalation formulation containing 590 mg of amikacin in 8.4 mL vial
Supplied in single-use vials intended for one daily dose via the Lamira Nebulizer System
Packaged with detailed Instructions for Use including nebulizer operation and storage conditions
No oral, intravenous, or intramuscular formulations of Arikayce; this formulation is unique for inhalation
Formulation includes inactive ingredients such as dipalmitoylphosphatidylcholine (DPPC), cholesterol, sodium chloride, sodium hydroxide (for pH adjustment), and water for injection
Must be stored refrigerated between 2°C and 8°C and protected from freezing prior to use
Once at room temperature (up to 25°C) the suspension is stable for 4 weeks before discarding
The suspension should be shaken well before each use to ensure uniform distribution of liposomal particles