Tag: Laboratory testing

According to the FDA drug label, phenazopyridine can interfere with urinalysis based on color reactions and spectrometry, potentially leading to misleading results. This common over-the-counter medication, often used for urinary tract infection symptoms, can cause a false positive, complicating diagnosis if not properly disclosed.

Contrary to the assumption that heparin might increase clotting factors, clinical studies have consistently demonstrated that heparin actually *reduces* plasma fibrinogen levels, particularly in patients with existing hyperfibrinogenemia. This effect is a key component of its therapeutic role as an anticoagulant and anti-inflammatory agent.

Heparin is a critical anticoagulant used in phlebotomy, with green-top blood collection tubes containing either its sodium or lithium salt to keep blood from clotting. Understanding **how does heparin prevent blood from clotting by phlebotomy** is key to appreciating its role in producing accurate laboratory test results for plasma chemistry.

While the activated partial thromboplastin time (aPTT) is the standard test for monitoring unfractionated heparin therapy, this anticoagulant can also cause a significant, though often artifactual, prolongation of the prothrombin time (PT). This complex interaction is crucial for healthcare professionals to understand, especially during transitions to oral anticoagulants like warfarin.

As a water-soluble B vitamin, excess biotin is not stored in the body and is primarily cleared through urine. The rate at which it leaves the body, or how long does it take to get biotin out of your body, is not a simple, single answer; it is influenced by dosage, the duration of supplementation, and an individual's kidney function. For most people, biotin has a very short half-life, but with the high-dose supplements common today, it can take significantly longer to clear from the system.