Blood Drug Testing

Do herbal medicines affect blood tests and hiv testing?

Do herbal medicines affect the body's overall chemistry so much that they could yield faulty results when a doctor or clinician performs a blood test and an hiv test? Do Chinese medicines or other herbal medicines interfere with or deter a proper, accurate blood test or hiv test?

Public Comments

1. No, it should not
2. Complicated answer to a fairly simple question. Some medications can cause a false positive to certain blood tests, but none will cause a false negative. There are two general types of HIV tests. One looks for antibodies to the virus that the body produces, and the other looks for the RNA of the virus itself. Neither the antibodies nor the virus itself will be affected by any herbal medicine to the extent that the test won't detect an infection. The tests that look for viral RNA (or DNA, for some kinds of viruses) don't get false positives. The antibody tests aren't quite as sure, though. They can be fooled into thinking an infection is there when it really isn't. There are certain medications that are chemically similar enough to any given antibody that an antibody test will show up as a false positive. Think of a lock and key. Only one shape of key will open the lock on your front door - the key is the antibody, and the lock is the virus. When the key fits the lock perfectly, it turns and opens. The antibody binds to the virus and destroys it. Some keys will fit into the lock, but they won't turn. They look enough like the right key that the lock will accept them, but they aren't quite right. That's what some medications can do. They chemically look enough like the antibody that the test thinks it's there, when it really isn't. That's why confirmatory testing is ALWAYS done after an initial positive test - to rule out a false positive and make sure that someone isn't told they have a disease they really don't.