Drug Nomenclature
International Nonproprietary Names (INNs) in main languages (French, Latin, Russian, and Spanish):
Pharmacopoeias
In China, Europe, International, and US. European Pharmacopoeia, 6th ed., 2008 and Supplements 6.1 and 6.2 (Amikacin). An antimicrobial substance obtained from kanamycin A. A white or almost white powder. Sparingly soluble in water; practically insoluble in alcohol and in acetone; slightly soluble in methyl alcohol. A 1% solution in water has a pHof9.5toll.5. The United States Pharmacopeia 31, 2008 (Amikacin). A white crystalline powder. Sparingly soluble in water. pH of a 1% solution in water is between 9.5 and 11.5. Store in airtight containers.
Amikacin Sulfate
Drug Nomenclature
International Nonproprietary Names (INNs) in main languages (French, Latin, Russian, and Spanish):
Pharmacopoeias
In China, Europe, International, Japan, and US. European Pharmacopoeia, 6th ed., 2008 and Supplements 6.1 and 6.2 (Amikacin Sulphate). A white or almost white powder. It loses not more than 13.0% of its weight on drying. Freely soluble in water; practically insoluble in alcohol and in acetone. ThepHofa 1% solution in water is between 2.0 and 4.0. Store in airtight containers. The United States Pharmacopeia 31, 2008 (Amikacin Sulfate). Amikacin sulfate having a molar ratio of amikacin to H2SO4 of 1:2 contains the equivalent of not less than 674 micrograms and not more than 786 micrograms of amikacin per mg, calculated on the dried basis. Amikacin sulfate having a molar ratio of amikacin to H2SO4 of 1:1.8 contains the equivalent of not less than 691 micrograms and not more than 806 micrograms of amikacin per mg, calculated on the dried basis. A white crystalline powder. Freely soluble in water. pH of a 1 % solution in water is between 2.0 and 4.0 (1:2 salt) and 6.0 to 7.3 (1:1.8 salt). Store in airtight containers.
Incompatibility
For discussion of the incompatibility of aminoglycosides, including amikacin, with beta lactams, see under Gentamicin Sulfate, p.282. Amikacin is also reported to be incompatible with various other drugs. However, reports are contradictory in many cases, and other factors, such as the strength and composition of the vehicles used, may play a role.
Stability
Solutions may darken from colourless to pale yellow but this does not indicate a loss of potency.
Adverse Effects, Treatment, and Precautions
As for Gentamicin Sulfate. Peak plasma concentrations of amikacin greater than 30 to 35 micrograms/mL or trough concentrations greater than 5 to 10 micrograms/mL should be avoided. Amikacin affects auditory (cochlear) function to a greater extent than gentamicin.
Effects on the eyes
A report of retinal damage after intravitreal injection of amikacin.
Interactions
As for Gentamicin Sulfate.
Antimicrobial Action
As for Gentamicin Sulfate. Amikacin is active against a similar range of organisms although it is also reported to have some activity against Nocardia asteroides, Mycobacterium tuberculosis, and some atypical mycobacterial strains. Amikacin is not degraded by many of the common enzymes often responsible for acquired aminoglycoside resistance. In consequence, cross-resistance with gentamicin and other aminoglycosides is infrequent and amikacin may be effective against strains resistant to other aminoglycosides. However, resistant strains of Gram-negative bacteria and staphylococci have been reported, and it is generally reserved for infections resistant to other aminoglycosides, although reports differ as to the extent and speed of the development of amikacin resistance where it has been widely used.
Pharmacokinetics
As for Gentamicin Sulfate. On intramuscular injection, peak plasma-amikacin concentrations of about 20 micrograms/mL are achieved 1 hour after a 500-mg dose, reducing to about 2 micrograms/mL 10 hours after injection. A plasma concentration of 38 micrograms/mL has been reported after the intravenous infusion of 500 mg over 30 minutes, reducing to 18 micrograms/mL 1 hour later. Amikacin has been detected in body tissues and fluids after injection; it crosses the placenta but does not readily penetrate into the CSF, although substantial penetration of the blood-brain barrier has been reported in children with meningitis. A plasma half-life of about 2 to 3 hours has been reported in patients with normal renal function. Most of a dose is excreted by glomerular filtration in the urine within 24 hours.
Uses and Administration
Amikacin is a semisynthetic aminoglycoside antibiotic derived from kanamycin and is used similarly to gentamicin in the treatment of severe Gram-negative and other infections. It is given as the sulfate, and is generally reserved for the treatment of severe infections caused by susceptible bacteria that are resistant to gentamicin and tobramycin. Amikacin has also been given with antimycobacterials in the treatment of non-tuberculous mycobacterial infections. As with gentamicin, amikacin may be used with penicillins and with cephalosporins; the injections should be given at separate sites. Doses of amikacin sulfate are expressed in terms of amikacin base; 1.3 g of amikacin sulfate is equivalent to about 1 g of amikacin. Adults and children may be given 15 mg/kg daily in equally divided doses every 8 or 12 hours by intramuscular injection. In life-threatening infections, the dose may be increased in adults up to a maximum of 500 mg every 8 hours. A dose of 7.5 mg/kg daily in two divided doses (equivalent to 250 mg twice daily in adults) may be given for the treatment of uncomplicated urinary-tract infections. The same doses may be given by slow intravenous injection over 2 to 3 minutes, or by intravenous infusion. In adults, 500 mg in 100 to 200 mL of diluent has been infused over 30 to 60 minutes; proportionately less fluid should be given to children. Neonates may be given 10 mg/kg as a loading dose, followed by 15 mg/kg daily in two divided doses. If given by intravenous infusion, an infusion period of 1 to 2 hours is recommended. It has been suggested that doses may need to be adjusted in preterm neonates. Treatment should preferably not continue for longer than 7 to 10 days, and the total dose given to adults should not exceed 15 g. Peak plasma concentrations greater than 30 to 35 micrograms/mL or trough plasma concentrations greater than 5 to 10 micrograms/mL should be avoided. Dosage should be adjusted in all patients according to plasma-amikacin concentrations, and this is particularly important where factors such as age, renal impairment, or prolonged therapy may predispose to toxicity, or where there is a risk of subtherapeutic concentrations. For discussion of the methods of calculating aminoglycoside dosage requirements, see Administration and Dosage, under Gentamicin. As with some other aminoglyco sides, once-daily dosage has been used successfully with amikacin without increasing toxicity, but local guidelines should be consulted (see also Once-daily Dosage). A 0.25% solution has been instilled into body cavities in adults. A liposomal formulation of amikacin is under investigation.
Preparations
British Pharmacopoeia 2008: Amikacin Injection; The United States Pharmacopeia 31, 2008: Amikacin Sulfate Injection
Single-ingredient Preparations
Argentina: Biklin; Greini; Riklinak; Australia: Amikin; Austria: Biklin; Belgium: Amukin; Brazil: Amicacil; Amicalin; Amicilon; Amikin; Aminocina; Bactomicin; Klebicil; Novamin; Canada: Amikin; Czech Republic: Amikin; Amikozit; Miacin; Denmark: Biklin; Finland: Biklin; France: Amiklin; Germany: Biklin; Greece: Amicagel; Amicasil; Amikan; Biorisan; Briklin; Durocin; Farcyclin; Flexelite; Fromentyl; Kancin-Gap; Lanomycin; Lifermycin; Likacin; Micalpha; Orlobin; Remikin; Rovericlin; Selaxa; Uzix; Hong Kong: Amikin; Apalin; Selemycin; Hungary: Amikin; Likacin; India: Amcin; Amicin; Amicip; Mikacin; Ireland: Amikin; Israel: Amikin; Likacin; Italy: Amicasil; Amikan; BB-K8; Chemacin; Dramigel; Likacin; Lukadin; Mediamik; Migracin; Mikan; Mikavir; Nekacin; Pierami; Sifamic; Malaysia: Amikin; Selemycin; Mexico: Agnicin; Akacin; Amicina; Amikafur; Amikalem; Amikasons; Amikavi; Amikayect; Amikin; Amiyec; AMK; Baxi-K; Beramikin; Biclin; Biokacin; Cramigen; Gamikal; Georkacina; Kafran; Karmikin; Libamic; Lisobac; Mikazul; Oprad; Plokim; Sermicina; Yectamid; Netherlands: Amukin; New Zealand: Amikin; Portugal: Biclin; Kamina; Russia: Amikozit (Амикозит); Selemycin (Селемицин); South Africa: Amikin; Kacinth-A; Singapore: Amikin; Selemycin; Spain: Biclin; Kanbine; Sweden: Biklin; Switzerland: Amikin; Thailand: Akacin; Akicin; Amikasol; Amikin; Anbikin; Siamik; Tipkin; Tybikin; United Arab Emirates: Mikacin; United Kingdom: Amikin; United States: Amikin; Venezuela: Amikavax; Amikayect; Behkacin; Biklin