⚠️ Warnings
Caution is required when administering to patients:
with renal impairment,
with hearing or vestibular impairment,
with neuromuscular disorders (e.g. myasthenia gravis, parkinsonism, as muscle weakness may be exacerbated due to the curare-like effect that amikacin may potentially exert on the neuromuscular junction), and
patients treated with other aminoglycosides immediately prior to amikacin use.
Patients treated with parenteral aminoglycosides should be under close clinical observation because of the potential ototoxicity and nephrotoxicity associated with their use.
Toxic effects of aminoglycosides, including amikacin, are more common in patients with renal impairment, when high doses are administered, and during prolonged treatment.
The safety of treatment exceeding 14 days has not been established. Other factors that increase the risk of aminoglycoside toxicity include advanced age and dehydration.
Neuro/ototoxicity
Neurotoxicity, manifesting as vestibular and/or bilateral auditory ototoxicity, may occur in patients treated with aminoglycosides. The risk of aminoglycoside-induced ototoxicity is higher in patients with renal impairment and in patients, including those who are otherwise healthy, whose therapy is extended to 5–7 days. High-frequency deafness usually appears first and can only be detected by audiometric testing. Vertigo may occur, which may be indicative of vestibular damage. Other manifestations of neurotoxicity may include numbness, tingling, muscle twitching, and convulsions.
Patients with mitochondrial DNA mutations (particularly the 1555 A-to-G nucleotide substitution in the 12S rRNA gene) are at increased risk of ototoxicity, even when aminoglycoside serum levels remain within the recommended range during treatment. Alternative treatment options should be considered for these patients. In patients with a family history of relevant mutations or aminoglycoside-induced deafness, alternative treatment or genetic testing should be considered before administration.
Patients who develop cochlear or vestibular damage may not experience any symptoms during treatment that would warn them of developing eighth-nerve toxicity, and complete or partial irreversible bilateral deafness or severe vertigo may occur after discontinuation of the product. See also section 4.8.
Aminoglycoside-induced ototoxicity is usually irreversible.
Neuromuscular toxicity
Neuromuscular blockade and respiratory paralysis have been reported following parenteral injection, topical application (such as orthopaedic or abdominal irrigation or local treatment of empyema), and oral use of aminoglycosides.
The possibility of respiratory paralysis should be considered regardless of the route of aminoglycoside administration, particularly in patients concomitantly receiving medicinal products that cause neuromuscular blockade. See also section 4.5.
If neuromuscular blockade occurs, calcium salts may reverse respiratory paralysis; however, mechanical ventilation may still be necessary. Neuromuscular blockade and muscle paralysis have been demonstrated in laboratory animals given high doses of amikacin.
Renal toxicity
Aminoglycosides are potentially nephrotoxic. Renal toxicity is independent of the plasma sample obtained at peak concentration (Cmax). The risk of nephrotoxicity is higher in patients with renal impairment and in patients receiving high doses or undergoing prolonged therapy.
Patients must be well hydrated during treatment, and renal function should be assessed by standard methods before starting therapy and daily during treatment. See section 4.2.
Reduction of daily doses and/or extension of the dosing interval is required in the event of signs of renal dysfunction, such as: cylindruria, presence of leukocytes or erythrocytes in urine, albuminuria, decreased creatinine clearance, decreased urine specific gravity, hyperazotaemia, increased BUN, rise in serum creatinine, and oliguria. Treatment should be discontinued if azotaemia increases or if there is a progressive decrease in urine output.
Patient monitoring
Renal function and eighth cranial nerve function should be carefully monitored, particularly in patients with known or suspected renal impairment at the start of therapy, as well as in patients whose renal function is initially normal but who develop renal impairment during therapy. Serum amikacin concentrations should be monitored when possible to ensure adequate levels and to prevent potentially toxic levels. Urine should be examined for decreased specific gravity, increased protein excretion, and the presence of cells or sediment. Blood urea nitrogen, serum creatinine, or creatinine clearance should be measured at regular intervals. Serial audiograms should be obtained when possible in patients old enough to be tested, particularly high-risk patients. Evidence of ototoxicity (dizziness, vertigo, tinnitus, roaring in the ears, and hearing loss) or nephrotoxicity requires discontinuation of treatment or dose adjustment. See section 4.8.
Amikacin treatment should be discontinued upon the occurrence of tinnitus, subjective hearing deterioration, or when serial audiograms demonstrate significant loss of high-frequency tone perception.
As with other antibiotics, the use of amikacin may result in overgrowth of non-susceptible organisms. If this occurs, appropriate therapy should be initiated. Aminoglycosides applied locally as part of a surgical procedure are rapidly and almost completely absorbed (with the exception of the urinary bladder).
Irreversible deafness, renal failure, and death caused by neuromuscular blockade have been reported in connection with aminoglycoside irrigation of the surgical field (regardless of extent).
Macular infarction has been reported following intravitreal administration of amikacin (injection into the eye), leading in some cases to permanent loss of vision.
Elderly patients
Elderly patients may have reduced renal function that may not be apparent from routine screening tests such as BUN or serum creatinine. Determination of creatinine clearance may be more useful. Monitoring of renal function during aminoglycoside therapy is particularly important in elderly patients.
Paediatric population
Administration of aminoglycosides to premature and neonatal infants requires caution due to the renal immaturity of these patients, resulting in prolongation of the serum half-life of these drugs.
Special warnings/precautions concerning excipients
This medicinal product contains 354 mg of sodium per 100 ml, equivalent to 17.7% of the WHO recommended maximum daily dietary intake of sodium for an adult, which is 2 g sodium.
Interference with laboratory tests
When cephalosporins are administered concurrently, serum creatinine tests may yield falsely elevated values. In samples (e.g. serum, cerebrospinal fluid, etc.) collected for aminoglycoside testing, mutual inactivation of amikacin and beta-lactam antibiotics may continue, leading to inaccurate results. Samples should therefore be analysed immediately after collection, or frozen, or the beta-lactam antibiotics must be inactivated by the addition of beta-lactamase. Inactivation of aminoglycosides is clinically significant only in patients with severe renal impairment.