Allergen - Drug - Metronidazole antibiotic Test

Metronidazole is an antibiotic used against anaerobic bacteria. It is also used in the treatment of giardiasis, amoebiasis, trichomoniasis, treponemal infections, etc. metronidazole can also be tried to treat acne. Metronidazole is also used in the treatment of anaerobic brain abscess, vincent's angina, h. Pylori infection. The drug is metabolized in the liver and is excreted out through urine. Adverse effects of the drug include anorexia, nausea, abdominal cramps, urticaria, vertigo, confusion, etc. Allergy to this drug is a rare condition. But the allergic conditions are increasing these days due to increased usage of the drug for the treatment of anaerobic infections. Symptoms of hypersensitivity include skin rashes, urticaria, nausea, vomiting, etc.

Patients should be awake to the allergic state they are facing. It would be better if the patients discover the allergic condition in the initial state. Allergy to the drug is recognized by the presence of IgE antibodies against the drug in the blood of the patient. Blood test or skin prick test is conducted to know the allergy to the drug. The patient should be wearing a sleeveless or half sleeve dress so that it would be easy to draw blood. A full sleeve dress whose sleeves can be rolled up easily can also be worn.

This test is usually performed to know if the allergy is due to metronidazole or not. This helps in the withdrawal of the drug from the treatment regimen and relieving of the symptoms. In case the test is positive the allergy can be treated by injecting gradually increasing doses of the drug. This will lead to resistance to the drug and allergic symptoms will not occur.

5-10 ml of blood is drawn to conduct the investigation. The patient should be explained about the procedure before itself to reduce their anxiety. A cotton pad dipped in alcohol or spirit is used to sterilize the area of skin from the area where the blood is drawn. A needle is pierced through the skin into the vein at the cubital fossa and blood is withdrawn. The withdrawn blood is emptied into a container containing an anticoagulant so that the blood does not get a clot. This sample is sent to the research laboratory for testing. IgE antibodies against the drug are looked for. Skin prick tests can also be done for this purpose. A small sample of the drug is injected into the skin and allergic reactions are looked for.