The vancomycin peak and trough represent two extremes in terms of the levels of concentration of this antibiotic in a patient's bloodstream. At the peak, large amounts are circulating, and at the trough, the levels fall very low. Doctors must time dosing with the goal of keeping levels consistent by delivering medication before concentrations reach a trough. For some patients, a doctor may recommend regular monitoring during vancomycin therapy to keep track of levels and adjust doses and timing if necessary.
Vancomycin is a very aggressive antibiotic available in the form of an intravenous injection for treating a number of infections. There are some toxicity concerns with this medication and it is not a first choice treatment. While on vancomycin, a patient may need to stay in the hospital to receive supportive care for an infection, although sometimes it is possible to get injections at home or to receive them on an outpatient basis. It is also important to make sure the infection responds to treatment, and a doctor may need to check on vancomycin peak and trough levels.
Typically, the medication reaches peak concentration between one and two hours after administration. Depending on the size of the dose, the patient's general health, and other factors, the timing of the trough may vary. A doctor can request a peak reading after administration and check back to see when the patient hits the trough. The health care provider can adjust the timing of future doses to make sure the levels rise before bottoming out, keeping an even amount of medication in the bloodstream.
For some patients on vancomycin, there is a risk of liver or kidney damage. A doctor may need to take vancomycin peak and trough levels to see if a patient has dangerously high levels that might precede organ damage. If the patient's blood reveals high concentrations, the doctor can lower the dose and adjust the timing to address the issue. The goal is to prevent damage by being proactive with medication dosing, keeping the patient as safe as possible during a course of therapy.
A hospital lab can analyze blood to check for vancomycin peak and trough levels at a request from a physician. The doctor may write an order in the patient's chart for a nurse to take regular samples and send them to the lab for analysis. With some patients, only a single set of readings is necessary to allow the doctor to perfect the timing of the doses. Other patients may require regular measurements because of concerns about side effects and toxicity.