Vancomycin - Serum

Vancomycin is an effective antibiotic that treats severe infections caused by gram-positive bacteria like Staphylococcus. Being a strong antibiotic, vancomycin is mainly prescribed for treating harmful bacteria resistant to penicillin and methicillin.

The vancomycin serum test measures the concentration of vancomycin in the blood, which is useful for therapeutic dose monitoring of the antibiotic after treatment.

Vancomycin is effective on two strains of Staphylococcus:

• methicillin-resistant Staphylococcus epidermidis 
• methicillin-resistant Staphylococcus aureus.

Since the drug shows poor absorption in the gut when taken through the oral route, it is best to administer it through the intravenous route. The intravenous administration of vancomycin treats infections like septicaemia, endocarditis, osteomyelitis, meningitis, and some forms of pneumonia.

When the doctor injects vancomycin into blood, the drug enters the circulatory pathway and reaches the site of infection at the required therapeutic dose. During this process, the level of vancomycin in the blood rises and falls as the body tries to metabolise it. Since the drug’s efficacy depends on bioavailability, the vancomycin TDM test becomes essential.

However, an excess drug dose leads to toxicities that could damage the hearing capacity and kidney function. In such a case, it is crucial to do a vancomycin serum test and ensure that the drug is present adequately and not in excess.

Apollo 24|7 offers a vancomycin serum test with several uses other than just measuring the bioavailability of the drug.

Here are some applications of the vancomycin TDM test:

• To make sure that the patient is not underdosed.
• To check for a renal malfunction during antibiotic treatment.
• Used when the treatment is ineffective for certain bacterial infections.
• During a strict treatment regime with the administration of the drug at frequent intervals.
• Used for the therapeutic dose monitoring of the drug.
• To test the concentration of the drug when administered with other types of medications, such as aminoglycosides.
• To check the bioavailability of the drug during prophylactic administration before surgeries.

The vancomycin serum test is a timed interval test in which the therapeutic dose monitoring occurs multiple times during the treatment. Vancomycin TDM test is an essential diagnostic test because soon after administering the drug, organs like the liver and kidney work towards excretion of the chemical from the body.

Acute kidney injury is a dangerous side effect of vancomycin therapy. With indiscriminate use of the drug, the bacterial strains are likely to be resistant to the therapy.

In such cases, the doctor prescribes a higher drug dose that might lead to acute kidney injury within 10 days of the treatment.

A vancomycin serum test ensures that the infection is treated without having any harmful effects on the kidney. 
 

Medically reviewed by Dr. Srikanth M, Haematologist, Apollo Hospitals Greams Road, Chennai