Colistin

Type of Medication: Antibiotic

Indications: Treatment, prophylaxis and eradication of Pseudomonas aeruginosa and Achromobacter infection

Side Effects: Neurotoxicity especially with excessive doses (including perioral & peripheral paraesthesia, vertigo, muscle weakness, slurred speech, visual disturbance, apnoea, confusion and psychosis),nephrotoxicity, hypersensitivity reactions including rash. Inhaled therapy may cause sore throat , cough and bronchospasm which may be negated by the use of inhaled beta agonists. Bolus Colomycin should only be administered via a central line.

Route of administration: Adult (Intravenous)

Dose:75,000 units/kg/day Standard adult dose (over 60 kg) 2 million units tds. Reduce dose in renal failure or when used with an aminoglycoside (avoid if possible).

Administration: Infusion-dilute with 50 ml 0.9% saline and infuse over 30 minutes. If neurological side-effects are a problem,use 75,000 units/kg/day in 3 divided doses instead of 2 MU three times a dayBolus dose-dilute 2 million units in 10 ml NaCl 0.9% and give over 3-5 minutes through central access (adult only)

Route of administration: Adult (Nebulised)

Dose:1-2 million units bd. 1 million units bd if administered via the i-neb.

Administration: Reconstitute 1×1 MU vial with 2 ml WFI and 1×1 MU vial with 2 ml NaCl 0.9% and mix together. If administered via the i – neb reconstitute one vial of Promixin with 1 ml of WFI.

Route of administration: Paediatric (Intravenous)

Dose:75,000 units/kg/day in 3 divided doses to max of 2 mu tds. Reduce dose in renal failure or when used with an aminoglycoside (avoid if possible)

Administration:

Route of administration: Paediatric (Nebulised)

Dose:children <2 years: 500,000 – 1 million units bd. 1 million units bd if administered via the i-neb. Children > 2 years: 1-2 million units bd.

Administration: As for adults

Examples of some Drug Interactions

nteracting drug: Alendronate, Etidronate – increased risk of hypocalcaemia

Interacting drug: Aminoglycosides – increases risk of nephrotoxicity, reduces doses if concurrent use essential

Interacting drug: Amphotericin – increased risk of nephrotoxicity

Interacting drug: Ciclosporin – increased risk of nephrotoxicity

Interacting drug: Loop diuretics – increased risk of ototoxicity

Interacting drug: Muscle relaxants – enhance muscle relaxant effect

Interacting drug: pyridostigmine, neostigmine – antagonised effect

Interacting drug: Teicoplanin – increased risk of nephrotoxicity and ototoxicity

Interacting drug: Vancomycin – increased risk of nephrotoxicity