| name | Polymyxin B |
| classification | Antibiotic (Aminoglycoside-like) |
| pharmacokinetics | | absorption | Poorly absorbed orally; administered primarily parenterally (intravenous or intramuscular). | | distribution | Concentrates in the kidneys, lungs, and intestines. Limited penetration into the CNS. | | metabolism | Minimal hepatic metabolism. | | excretion | Primarily excreted by the kidneys. Renal impairment can significantly prolong half-life. |
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| suggested dosage | | note | Dosage depends on the severity of infection, patient's renal function, and specific formulation. Consult a physician for appropriate dosage. | | example dosage IV | 1-2 million units IV every 8-24 hours. | | example dosage IM | Note: Use caution and expertise for IM administrations, which may not be the preferred route. |
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| indications | Treatment of serious systemic gram-negative bacterial infections, especially those caused by Pseudomonas aeruginosa, when other antibiotics are ineffective or contraindicated. |
| safety in pregnancy | Category C. Potential risks to the fetus exist. Use only if the potential benefit justifies the potential risk. Monitor mother and fetus closely. Consult a physician. |
| safety in breastfeeding | Potential for excretion into breast milk. Caution advised. Consider the benefits and risks for both mother and infant. Consult a physician. |
| side effects | | 1 | Nephrotoxicity (kidney damage): This is a major concern and dose-dependent. | | 2 | Neurotoxicity (nerve damage): including peripheral neuropathy. | | 3 | Ototoxicity (ear damage): Risk of hearing loss. | | 4 | Gastrointestinal upset: Nausea, vomiting, diarrhea. | | 5 | Hypersensitivity reactions: Rash, itching, fever, anaphylaxis. |
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| alternatives | |
| contraindications | | 1 | Known hypersensitivity to polymyxin B or other aminoglycosides. | | 2 | Significant renal impairment. | | 3 | Pre-existing neuropathy. | | 4 | Use with caution in patients with pre-existing hearing or balance problems. |
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| interactions | Polymyxin B can interact with other nephrotoxic drugs, increasing the risk of kidney damage. Use with caution with other ototoxic drugs. |
| warnings and precautions | | 1 | Monitor renal function closely during treatment. | | 2 | Monitor for signs of neuropathy, especially in patients with pre-existing conditions. | | 3 | Monitor for signs of ototoxicity. | | 4 | Adjust dosage based on creatinine clearance. | | 5 | Use the lowest effective dose and shortest duration possible. | | 6 | Be wary of potential cross-resistance with other aminoglycosides. |
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| additional information | | 1 | Polymyxin B sulfate is the most common formulation. | | 2 | Topical formulations are available for skin infections but are not suitable for systemic infections. | | 3 | Intravenous administration is more common, especially for severe infections. In some situations, intramuscular administration may be used. | | 4 | Dosage should be carefully adjusted to individual patient factors, particularly renal function. |
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| patient specific considerations | | age | 25 years: Generally, no specific age-related considerations are required, but this should be discussed with a physician. | | weight | 70 kg: No dosage adjustments are required based solely on weight. Renal function is a key factor for adjustment, and must be assessed. |
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