AMIKACIN is an antibiotic under the class of aminoglycosides with amino sugars in glycosidic linkages. Amikacin is a semisynthetic product and used to treat conditions such as Bacterial infections, uncomplicated urinary tract infections, severe gram-negative infections resistant to gentamicin and tobramycin, and short term treatment of serious infections caused by Pseudomonas species, Escherichia coli, species of indole-positive and indole negative, Proteus, Klebsiella, Enterobacter, Serratia, Salmonella, Shigella and Acinetobacter. Get to know how Amikacin works, its side effects, precautions, interactions, and contraindications.
How does Amikacin work?
Amikacin has the capacity to kill the bacteria by binding to 30S ribosomes and inhibit bacterial protein synthesis. The drug penetrates the bacterial cell membrane through pores.
Resistance to aminoglycosides may be by
- Aminoglycoside inactivating enzymes.
- Decreased binding of aminoglycosides to ribosomes.
- Decrease in permeability to the antibiotic.
Properties of Amikacin
- Used as the sulfate salt.
- Not absorbed orally.
- Penetration into CSF is very poor.
- Bactericidal in nature.
- Have a narrow margin of safety.
- Ionized in solution.
- It is highly water-soluble.
- Effective in aerobic gram-negative infections.
- Exhibit synergic effect.
- Shows partial cross-resistance.
- Excreted unchanged through kidneys.
Availability of Amikacin
Amikacin is not absorbed orally(as it ionizes in solution)therefore it is given through the parenteral route only.
Injections are available in 10 ml vial(100 mg/2 ml) and 2 ml vial (250 mg/2 ml),(500 mg/2 ml).Intramuscular or intravenous injection or infusion.
Dosage
The dosage of Amikacin that might be appropriate for you depends on the severity of your condition, age, medical history, as well as your body’s reaction after the first dose of the drug. Your physician should be informed about your medical history and condition, for example, allergies, pregnancy, nerve diseases and a kidney disease before you are handed over a prescription.
Adult- 15 mg/kg body weight daily in two divided doses, increased to 22.5 mg/kg body weight daily in three divided doses in severe infections. (max 1.5g daily for 10 days, max.cumulative dose is 15g).
Child- 15 mg/kg body weight daily in two divided doses.
Neonates- loading dose is 10 mg/kg body weight followed by 15 mg/kg body weight in
two divided doses.
Uses of Amikacin
- Bacteremia
- Bone infection
- Cystic Fibrosis
- Febrile Neutropenia
- Intraabdominal Infection
- Joint Infection
- Meningitis
- Nosocomial Pneumonia
- Peritonitis
- Pneumonia
- Skin or Soft Tissue Infection
- Tuberculosis, Active
- Urinary Tract Infection
Short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including Pseudomonas species, Escherichia coli, species of indole-positive and indole-negative Proteus, Providencia species, Klebsiella, Enterobacter, Serratia species, and Acinetobacter (Mima-Herellea) species.
Contraindications of Amikacin
It is clear to inform your doctor about your medical and drug history in detail before you receive any sort of prescription. Amikacin should not be used if you have the following conditions:
- Myasthenia gravis(Myasthenia gravis (MG) is a long-term neuromuscular disease that leads to varying degrees of skeletal muscle weakness. The most commonly affected muscles are those of the eyes, face, and swallowing)
- Hypersensitivity.
- Pregnancy.
Special precautions
- Do not mix with any other drug in the same syringe.
- Avoid the use of other ototoxic drugs with amikacin.
- Avoid the use of other nephrotoxic drugs with amikacin.
- Avoid the use of drugs having muscle relaxant action along with amikacin.
- Pregnancy.
- Lactation.
- Renal impairment.
- Hypocalcemia.
- Postoperative or other conditions that depress neuromuscular transmission.
- Neonates.
- Infants.
- Elderly.
- Monitor renal functions before and during treatment, especially patients with renal dysfunction.
Adverse Effects of Amikacin
The following is a list of the probable side-effects that may occur from the constituent ingredients of Amikacin injection. Remember that these side-effects are possible but do not always occur. However, some of the side effects may be rare but serious. It is advisable to consult a physician immediately, in case any side effect or untoward reaction is noted:
- Ototoxicity(Vestibular and auditory damage)
Ototoxicity is the most important toxicity. The ear has two functions -one is hearing and the other is maintaining balance(vestibular apparatus). Both of these are affected by aminoglycosides. The drug gets concentrated in the inner ear and damages the sensory cells. As the cochlear cells cannot regenerate, there is permanent deafness. The auditory nerve degenerate. Elderly people are at a greater risk of developing deafness. Vestibular dysfunction results in headache, nausea, vomiting, dizziness, vertigo, nystagmus(Nystagmus is an involuntary, rapid and repetitive movement of the eyes), and difficulty in walking. Most symptoms subside in two weeks except ataxia(Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that includes gait abnormality) which may persist for 1-2 years.
- Nephrotoxicity
Amikacin attains high concentration in the kidneys and cause damage to the renal tubules These effects are reversible. The effect is more common in elderly patients. If there is impairment of renal function the dosing interval must be increased; in severe renal impairment, the dose should also be reduced. Serum concentration monitoring avoids both excessive and subtherapeutic concentration and can prevent toxicity and ensure efficacy.
- Neuromuscular blockade
It blocks neuromuscular transmission.
Rarely produce,
- Hypomagnesemia on prolonged therapy.
- Antibiotic-associated colitis, stomatitis; also reported
- Rash
- Blood disorders
- Acute muscular paralysis
- Albuminuria
- Azotemia.
Interactions Of Amikacin
In patients who have too many prescribed medications or in those who are taking unprescribed medicines, it is possible the Amikacin may not produce the desired result. Furthermore, such an individual may also have a higher probability to experience side effects. In order to prevent any drug interactions with amikacin, always remember to inform your doctor about all your medications and herbal products that you have been using regularly. Some interactions are listed below.
- Amphotericin B may lead to increased nephrotoxicity and reduced clearance of amikacin when used together.
- Increased nephrotoxic or ototoxic effects with other nephrotoxic or ototoxic drugs like loop diuretics,cephalothin, cisplatin etc
- Enhanced neuromuscular blockade with other neuromuscular drugs.
Pharmacokinetics of Amikacin
Absorption-IM administration is followed by rapid and complete absorption, with peak serum levels occurring after 0.5–1.5 hr. IV infusions over 0.5–1 hr produce serum levels similar to equal IM doses.
Distribution-Binding with plasma proteins is low. These agents distribute rapidly into the extracellular fluid compartment with a Vd of about 0.3 ±0.08 L/kg, which is increased by fever, edema, ascites, and fluid overload, and in neonates. Aminoglycosides accumulate markedly in some tissues, especially the renal cortex, to levels many times those found in the serum, particularly with frequent dosage intervals compared with the same dosage given at less frequent intervals. Levels in the CSF of patients with meningitis generally do not exceed 25% of serum levels, except in neonates; penetration into the eye is inadequate
for the treatment of intraocular infections. Penetration into lung tissues and sputum is low, and large doses might be necessary to optimally treat pneumonia with relatively insensitive organisms (eg, P. aeruginosa). The distribution of aminoglycosides into the peritoneal cavity of patients with peritonitis is therapeutically adequate.
Excretion- Elimination is via glomerular filtration of unchanged drug. Cl is about 90% of Clcr. After discontinuation, low levels of aminoglycoside can be detected in the urine for several days caused by the excretion of drugs that had accumulated in deep tissue compartments.
Drugs similar to Amikacin
Below is a list of drugs, which have the same composition, strength, and form as Amikacin. However, these medications cannot be interchanged or substituted for, without the consent of a healthcare professional.
Amicin 250 and 500 mg injection- Cadila Pharmaceuticals Ltd
Amicap 100,250 and 500 mg injection - Cipla Limited
Omikacin 100,250 and 500 mg injection -Cipla Limited
Parameters to Monitor in case of Amikacin administration.
Amicin 250 and 500 mg injection- Cadila Pharmaceuticals Ltd
Amicap 100,250 and 500 mg injection - Cipla Limited
Omikacin 100,250 and 500 mg injection -Cipla Limited
Parameters to Monitor in case of Amikacin administration.
- Renal function tests before and q 2–3 days during therapy.
- Audiometry and electronystagmography may be performed in patients able to cooperate. Monitor aminoglycoside serum concentrations carefully, especially in the elderly, those with renal impairment, hemodynamically unstable patients, and those requiring high peak serum concentrations or prolonged (>10 days) therapy.
- In adults receiving conventional therapy, monitor serum levels after a steady state are achieved. With once-daily therapy targeting high peaks and undetectable troughs, obtain levels after the first dose. Obtain follow-up levels if the renal function changes.
- In neonates or other patients with rapidly changing renal function, obtain serum drug concentrations initially and q 2–3 days until stable. However, with once- or twice-daily dosage and in pediatric patients, trough serum levels are often undetectable and other sampling strategies are necessary.
There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant the use of the drug in pregnant women despite potential risks.
Amikacin under Schedule H drug; Warning-" To be sold by retail on the prescription of a Registered Medical practitioner only"
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