Drugs.com states that a pill with the imprint "PLIVA 334" is 500 milligrams of metronidazole, or Flagyl. It is a prescription medication used to treat infections of the reproductive system, gastrointestinal tract, skin, vagina and other areas of the body, according to MedlinePlus.
Drugs.com explains that metronidazole should be taken exactly as a doctor prescribes. Even if symptoms improve, the infection may not be completely gone. Skipping doses or stopping this medication early may lead to further infection that is resistant to antibiotics. Drinking alcohol while taking metronidazole can lead to unwanted side effects such as fast heartbeats, warmth or redness under the skin, tingly feeling, nausea and vomiting. Other side effects of metronidazole include stomach pain, diarrhea, dizziness, loss of balance, vaginal itching or discharge, dry mouth, cough, runny nose and sore or swollen tongue. Taking metronidazole may lead to more serious side effects, such as numbness or tingling of hands or feet, white patches or sores on the mouth or lips, pain or burning during urination, watery or bloody diarrhea, vision problems, trouble concentrating, behavior changes, fever, chills, muscle pain, neck stiffness and severe skin reaction. A doctor should be notified immediately if any of these serious side effects occur.