Hexamycin (Gentamicin)

Hexamycin is indicated for the treatment of severe bacterial infections where rapid bactericidal activity is required.

• Severe sepsis and septic shock caused by susceptible gram‑negative bacteria.
• Hospital‑acquired pneumonia, including ventilator‑associated pneumonia, due to susceptible organisms.
• Complicated urinary tract infections and pyelonephritis when gram‑negative pathogens are identified.
• Intra‑abdominal infections such as peritonitis with documented susceptibility.
• Bone and joint infections caused by gram‑negative bacteria, used in combination therapy.
• Neonatal infections caused by gram‑negative organisms, administered under specialist guidance.

• Gentamicin exerts its antibacterial effect by binding irreversibly to the 30S subunit of bacterial ribosomes. This interaction disrupts the initiation complex and induces misreading of messenger RNA, leading to the production of abnormal proteins. The resulting protein synthesis inhibition is bactericidal, particularly against aerobic gram‑negative organisms, and contributes to rapid reduction of bacterial load in systemic infections. It also interferes with the integrity of the bacterial cell membrane, enhancing uptake of the drug.

Adverse reactions to Hexamycin may range from mild, transient symptoms to rare but serious events requiring medical attention.

Common

• Nephrotoxicity manifested as increased serum creatinine or reduced urine output.
• Ototoxicity presenting as tinnitus, hearing loss, or balance disturbances.
• Neuromuscular blockade causing muscle weakness, especially in patients with underlying disorders.
• Injection site reactions such as pain, erythema, or swelling.

Serious

• Acute kidney injury leading to oliguria or anuria.
• Permanent hearing loss or vestibular dysfunction.
• Severe allergic reactions including anaphylaxis.
• Respiratory paralysis in patients with myasthenia gravis.

Use of Hexamycin requires careful assessment of patient risk factors and monitoring to minimize toxicity.

• Assess renal function before initiation and monitor serum creatinine during therapy.
• Perform baseline and periodic audiometric testing, especially in prolonged courses.
• Adjust dose in patients with impaired kidney function or elderly individuals.
• Avoid use in patients with known hypersensitivity to aminoglycosides.
• Use with caution in neonates, pregnant or breastfeeding women due to limited safety data.
• Monitor neuromuscular function in patients with myasthenia gravis or receiving neuromuscular blockers.

Hexamycin can interact with other medicines, altering its efficacy or increasing the risk of toxicity.

Avoid

• Concurrent use with other nephrotoxic agents such as vancomycin, amphotericin B, or loop diuretics.
• Co‑administration with potent neuromuscular blockers (e.g., pancuronium) that may exacerbate paralysis.

Use with caution

• Concurrent therapy with other ototoxic drugs like loop diuretics or cisplatin.
• Use with other aminoglycosides or high‑dose penicillins that may affect renal clearance.
• Combination with diuretics may increase serum gentamicin concentrations.
• When given with drugs that affect serum potassium, monitor electrolytes closely.