tobramütsiin

Tobramütsiin is a semisynthetic aminoglycoside antibiotic structurally related to streptomycin. The drug is derived from the natural antibiotic tobramycin isolated from the soil bacterium *Micromonospora* and is modified to improve its spectrum and reduce toxicity. Tobramütsiin is available as a liquid for inhalation or as a crystalline salt for intravenous use. The formulation typically contains tobramycin sulphate and is marketed under a variety of trade names worldwide.

Tobramütsiin works by binding to the 30S subunit of the bacterial ribosome, causing misreading of mRNA and inhibition of protein synthesis. This bactericidal action is most effective against aerobic Gram‑negative bacilli, especially *Pseudomonas aeruginosa*. The drug has limited activity against Gram‑positive organisms and anaerobes. Because of its ion‑pairing properties, the drug is poorly absorbed orally and is therefore used parenterally or as a pulmonary inhalation solution to treat respiratory infections.

The main indication for tobramütsiin is chronic pulmonary infection in cystic fibrosis patients caused by *Pseudomonas aeruginosa*. It is also used for treating ventilator‑associated pneumonia, complicated urinary tract infections, and bacterial keratitis when other antibiotics are unsuitable. In the inhalation form, the usual dose is 300 mg twice daily, delivered via a nebulizer. Intravenous dosing ranges from 1.5 to 3 mg/kg/day divided into three to four doses, depending on the severity of infection and renal function.

Common adverse effects include nephrotoxicity and ototoxicity, particularly at high doses or in patients with pre‑existing renal disease. Other side effects can be neuromuscular blockade, rash, and gastrointestinal upset. Contraindications include hypersensitivity to aminoglycosides, severe renal impairment, and bilateral deafness. Drug interactions may occur with cisplatin, other nephrotoxic agents, and neuromuscular blocking drugs. Resistance to tobramütsiin is primarily due to enzymatic modification, efflux pumps, and target‑site mutations. Periodic susceptibility testing is recommended for long‑term therapy.