Related Experiment Videos
Ocular penetration of amikacin following intramuscular injection
Abstract:
Amikacin sulfate was given intramuscularly (IM) (7.5 mg/kg) to study its ocular penetration in man. Seventy-three patients with cataracts received a single dose and 35 received two doses given 5 1/2 to 12 hours apart. After a single dose the aqueous humor levels of the antibiotic between two and ten hours ranged from 0.15 to 3.10 mg/L (average and median, 1.0 mg/L). Two doses given 5 1/2 to eight hours apart produced an average level of 3.5 mg/L (range, 0.91 to 8.31 mg/L). When the second dose was given nine to 12 hours after the first, the aqueous humor levels were similar to those found for a single dose. Aqueous humor concentrations of 1.0 mg/L of amikacin would be expected to be bactericidal for most gram-negative bacterial pathogens, whereas levels of 3.5 mg/L would inhibit most strains of Staphylococcus aureus and many strains of Pseudomonas aeruginosa.
Insights
Amikacin sulfate demonstrates good ocular penetration in humans. Two doses administered within 5-8 hours achieve higher aqueous humor levels, potentially offering better antibacterial efficacy.
Area of Science:
- Ophthalmology
- Pharmacology
- Infectious Diseases
Background:
- Ocular infections require effective antibiotic penetration into the eye.
- Amikacin sulfate is a potent aminoglycoside antibiotic.
- Understanding amikacin's ocular pharmacokinetics is crucial for treating eye infections.
Purpose of the Study:
- To evaluate the ocular penetration and aqueous humor concentrations of amikacin sulfate in human patients.
- To determine the impact of single versus multiple dosing regimens on amikacin levels in the eye.
Main Methods:
- Intramuscular administration of amikacin sulfate (7.5 mg/kg) to 108 patients undergoing cataract surgery.
- Analysis of aqueous humor amikacin levels at various time points after single and multiple doses.
- Correlation of achieved concentrations with potential bactericidal activity.
Main Results:
- A single intramuscular dose resulted in average aqueous humor amikacin levels of 1.0 mg/L (range 0.15-3.10 mg/L) between 2-10 hours.
- Two doses given 5.5-8 hours apart yielded higher average levels of 3.5 mg/L (range 0.91-8.31 mg/L).
- Dosing the second dose 9-12 hours after the first did not significantly increase amikacin levels compared to a single dose.
Conclusions:
- Intramuscular amikacin sulfate achieves therapeutic concentrations in the human aqueous humor.
- A two-dose regimen with administration 5.5-8 hours apart enhances amikacin levels, potentially improving efficacy against resistant bacteria.
- Optimal dosing intervals are critical for maximizing amikacin's therapeutic effect in ocular infections.