Monitoring medicine allows health care providers to evaluate dosage levels and make adjustments as needed. Some medication dosages are close to levels that are toxic and could harm the patient. By regularly monitoring medicine levels in the bloodstream, problems can be avoided.
Several factors impact levels of medication in the bloodstream. Patient weight and age, and daily levels of activity, play a part in how much medication remains in the blood. In addition, each person's body breaks down and processes medications at different speeds. Medication delivery methods also drive the impact it has on the bloodstream. In some cases, simply changing the delivery method from a patch to a pill, or from a pill to injection, can make a difference.
Patients with kidney or liver function issues may not metabolize medications quickly enough to be safe. Failure to metabolize medications fast enough means medication remains in the body too long, potentially causing organ damage or other physiological problems. Monitoring medicine in such patients reduces the risk of medication-related problems.
Another reason for monitoring medicine is to maintain therapeutic medication levels. Many medications work best when there is a consistent level delivered and maintained in the body. Blood tests let health care providers know whether those levels are present. If not, a dosage adjustment corrects it, and the patient once again becomes properly medicated.
Specific groups are targeted for regular blood tests to monitor medicine. They include babies, the elderly, patients with kidney and liver disease, and those taking multiple medications that have the potential to interact with each other negatively. Monitoring medicine in these populations helps ensure that the medication benefits outweigh the risks.
To obtain the most accurate monitor reading, blood tests should be done at approximately the same time each visit. Most medications are their most potent within the first hour of ingestion. They are weakest shortly before the next dose is due to be taken. Medications most often monitored include antibiotics, ant-seizure medication, mental health medications, and organ transplant anti-rejection medications.
Pain management clinics also use blood tests to monitor their patients' medication use. The tests let the clinic know if the patient is overusing or underusing prescribed pain medications. If the patient is also using non-prescribed medications or illegal drugs, the blood test will show that. Many pain management clinics require patients to sign contracts agreeing to blood testing to monitor pain pill use.