Phencof-N Syrup is used to treat dry cough, throat irritation, sneezing, watery eyes & stuffed nose due to an allergy or common cold. It works by blocking the action of a natural substance (histamine) responsible for causing allergic reactions, reducing cough by blocking the cough receptor present in the brain, and helping ease a stuffy nose by shrinking the blood vessels in the nasal passage. This medicine may cause common side effects such as drowsiness, lightheadedness, nervousness, dizziness, vomiting, nausea, stomach pain, and restlessness. Before taking this medicine, inform your doctor if you are allergic to any of its ingredients, if you are pregnant or breastfeeding, and about all the medications you are taking and any pre-existing medical conditions.