What are the treatments for Pseudomonas aeruginosa?💊💊💊

Pseudomonas aeruginosa is a non-fermenting gram-negative bacillus and is a common opportunistic pathogen. It is widely distributed in the daily environment. Its main source is domestic sewage. It can cause lung infections, bloodstream infections, skin infections (often in people with burns), among others. In addition, Pseudomonas aeruginosa often causes nosocomial infections in patients. Studies have pointed out that patients with low immunity, skin and mucous membrane damage (such as mechanical ventilation, tracheal intubation, indwelling central venous catheter, etc.), structural lung disease (such as cystic fibrosis, bronchiectasis, chronic obstructive pulmonary disease, etc.), as well as patients who are using broad-spectrum antibiotics and have been hospitalized for a long time have a higher risk of infection with Pseudomonas aeruginosa. In addition, in patients with cystic fibrosis, respiratory infections caused by Pseudomonas aeruginosa may develop into chronic infections that are more difficult to treat.

Commonly used drugs against Pseudomonas aeruginosa.

β-lactam antibiotics:

• Penicillin: Piperacillin 9 to 16g intravenously daily, divided into 3 to 4 times.
• Penicillin/β-lactamase inhibitor: Piperacillin/tazobactam 4.5g intravenously every 6 to 8 hours.
• Cephalosporins: Ceftazidime 2g intravenously every 8 hours. Cefoperazone 2g intravenously every 8 hours. Cefepime 2g intravenously every 8 to 12 hours.
• Third generation cephalosporins/β-lactamase inhibitor: Cefoperazone/sulbactam 3g intravenously every 8 hours.
• Monobactams: Aztreonam 2g intravenously every 6 to 8 hours.
• Carbapenems: Imipenem/cilastatin 0.5 g intravenously every 6 hours or 1 g intravenously every 6 to 8 hours. Meropenem is administered intravenously at 1 g every 6 to 8 hours.

Aminoglycosides:

• Gentamicin: The dose is 7mg/(kg x d).
• Tobramycin: The dose is 7mg/(kg x d).
• Amikacin: The dose is 15mg/(kg x d).

Quinolones:

• Ciprofloxacin: The dose is 0.4g every 8 to 12 hours.
• Levofloxacin: The dose is 0.5 to 0.75 g daily.

Other:

• Polymyxin B: The dose is 2.5 to 5 mg/(kg x d) by intravenous infusion, divided into 3 to 4 times.
• Polymyxin E: The dose is 2.5 to 5 mg/(kg x d) by intravenous infusion, divided into 3 to 4 times.
• Fosfomycin: The dose is 300mg/(kg x d) by intravenous infusion, divided into 2 to 3 times.

Among these anti-Pseudomonas aeruginosa drugs, aztreonam, aminoglycosides, polymyxin and fosfomycin generally need to be used in combination with other antibiotics, and are not used alone. Clinically, the course of treatment will be determined according to the patient's condition. If the patient's condition is stable within 3 days after taking the drug, the recommended treatment course is 8 days. If the patient's efficacy is poor after treatment, the course of treatment can be extended to 10 to 14 days.

The drug resistance mechanism of Pseudomonas aeruginosa and its recommended medication.

Pseudomonas aeruginosa develops drug resistance by expressing efflux pumps, forming biofilms, changing target sites and outer membrane proteins, and producing β-lactamases. Some studies have pointed out that the resistance rate of Pseudomonas aeruginosa to polymyxin and amikacin is low, but the resistance rate to carbapenem can be as high as 23%. Drug-resistant Pseudomonas aeruginosa can be divided into:

• Multi-drug resistance: Pseudomonas aeruginosa is not susceptible to 3 or more antibacterial drugs against Pseudomonas aeruginosa.
• Extensive drug resistance: generally refers to that Pseudomonas aeruginosa is not sensitive to other antibiotics and only sensitive to polymyxins.
• Pandrug resistant: Pseudomonas aeruginosa is not sensitive to existing antibiotics.

Dual therapy regimens for extensively drug-resistant Pseudomonas aeruginosa:

1. Combined use of two β-lactam antibiotics: Ceftazidime + Piperacillin/tazobactam, Aztreonam + Piperacillin/tazobactam, Ceftazidime + Aztreonam, Ceftazidime + Cefoperazone/sulbactam.
2. Ciprofloxacin-based: Combine a β-lactam antibiotic or aminoglycoside.
3. Polymyxin-based: Combine a β-lactam antibiotic, ciprofloxacin, fosfomycin or rifampicin.
4. Based on β-lactam antibiotics: combined with ciprofloxacin, aminoglycoside or fosfomycin.

Triple therapy for extensively drug-resistant Pseudomonas aeruginosa:

1. Polymyxin + β-lactams + Ciprofloxacin.
2. Polymyxin + β-lactams + Fosfomycin.
3. Polymyxin (intravenous) + Polymyxin (aerosol inhalation) + Carbapenems.
4. Aztreonam + Ceftazidime + Amikacin.

Due to the increased risk of side effects (eg, increased nephrotoxicity with polymyxin and aminoglycosides, immune-mediated thrombocytopenia with rifampicin and piperacillin), rational drug selection and monitoring The patient's drug response.

Inhaled antimicrobials are believed to be the mainstay of treatment for Pseudomonas aeruginosa-related lung infections.

The goal of treatment for pulmonary infections caused by Pseudomonas aeruginosa is to reduce bacterial counts in the respiratory tract and improve patient outcomes. Antibiotics for inhalation have the advantage of a dosage form that allows the drug to accumulate in the respiratory tract to increase local drug concentration. This is believed to significantly improve the patient's respiratory symptoms and improve the patient's quality of life. There are now many inhaled formulations of antibiotic drugs into the field of research.