Aerosolized Antiinfective Agents

Clinical Indications for Pentamidine

• Aerosolized pentamidine is indicated for the prevention of Pneumocystisjiroveci pneumonia (PJP) in HIV-infected patients.
• It is ONLY used in prophylaxis; TMP-SMX is used to treat active PJP.

Aerosolized Pentamidine

• Rationale: Local targeted lung delivery and fewer side effects than systemic administration.
• PJP is caused by Pneumocystis jiroveci, occurring with immune system suppression.

Administration: Pentamidine

• Administered via Respirgard II nebulizer at 5–7 L/min from a 50-psi gas source.
• Mass median diameter (MMD) of 1–2 μm.

Side Effects: Pentamidine

• Common side effects: cough, bronchial irritation, shortness of breath, bad taste, and bronchospasm.
• Other side effects include spontaneous pneumothoraces, conjunctivitis, rash and digital necrosis.

Side Effects: Preventing airway effects

• Pretreatment with a β-adrenergic bronchodilator or parasympatholytic may help.
• Using a small particle size reduces airway impaction and increases alveolar deposition.

Environmental Contamination: Pentamidine

• Concerns include exposure to the drug and risk of tuberculosis infection.
• Precautions include using a nebulizer system with one-way valves and expiratory filter.
• Administer aerosol in negative-pressure room

Clinical Indications for Ribavirin

• Aerosolized ribavirin is indicated for the treatment of hospitalized infants with severe lower respiratory tract infection caused by respiratory syncytial virus (RSV).

Ribavirin

• Classified as an antiviral drug, active against RSV, influenza viruses, and herpes simplex virus.
• It is a nucleoside analog and virostatic, inhibiting both DNA and RNA viruses.

Clinical Use: Ribavirin

• Not recommended for routine RSV infection but may be considered for life-threatening infections.

Dosage: Ribavirin

• Administered as a 20-mg/mL solution via SPAG-2 nebulizer for 12 to 18 hr/day for 3-7 days.

Administration: Ribavirin

• Administered via SPAG nebulizer.
• MMD is approximately 1.3 μm.

Clinical Indications for Tobramycin

• Aerosolized tobramycin is indicated for the management of chronic Pseudomonas aeruginosa infection in cystic fibrosis (CF).
• Available as a liquid nebulized solution and a dry powder inhaler (TOBI PODHALER).

Aerosolized Tobramycin: Nebulized

• Dosage: 300 mg BID for 28 days consecutively, followed by 28 days off, using an approved nebulizer.

Aerosolized Tobramycin: DPI

• Dosage: Four 28 mg capsules twice daily for 28 days using a single-dose reusable DPI.

Precautions: Tobramycin

• Caution with renal, auditory, vestibular, or neuromuscular dysfunction.
• Incompatibility with β-lactam antibiotics.

Clinical Efficacy: Tobramycin

• Improves pulmonary function, decreases P. aeruginosa density, and reduces the need for IV antibiotics.

Clinical Indications for Aztreonam

• Aerosolized aztreonam is indicated to improve symptoms in CF patients with P. aeruginosa infection.

Aerosolized Aztreonam

• Dosage: 75 mg of lyophilized aztreonam, mixed with 1 mL of sterile diluent, three times per day for 28 days on and 28 days off, using the Altera Nebulizer System.
• Must be refrigerated

Clinical Indications for Zanamivir

• Inhaled zanamivir (Relenza) is indicated for influenza in adults and children 5 years and over who have been symptomatic for no more than 2 days.

Dosage and Administration: Zanamivir

• Administered via DPI (Diskhaler) as two inhalations (10 mg total) twice a day, approximately 12 hours apart, for 5 days.

Adverse Effects: Zanamivir

• May cause bronchospasm and should not be used in patients with preexisting lung disease.

Clinical Efficacy and Safety: Zanamivir

• Treatment results in approximately 1 day less to the median time to improvement in symptoms compared with placebo.

Respiratory Care Assessment: Before Treatment

• Assess patient for the presence of a disease in which use of the agent is indicated; risk of PJP; presence of severe RSV infection; chronic P. aeruginosa infection in CF patient; acute influenza infection within two days of onset
• Assess equipment
• Initial patient assessment

Respiratory Care Assessment: During Treatment

• Monitor for bronchospasm
• Vital signs
• Signs of improvement in symptoms
• Side effects

Respiratory Care Assessment: Long Term

• PFT studies
• Education regarding device use
• Use of bedside peak flow meters

General Contraindications

• Pentamidine: Bronchospasm and cough
• Ribavirin: Pregnant caregiver should avoid exposure
• Tobramycin & Aztreonam: Drug resistance
• Zanamivir: Caution in patients with preexisting airway disease