 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  cause drowsiness or a fast heartbeat. Ask your pharmacist about using those products safely. This medication may interfere with certain lab tests (such as gastric secretion tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug. Phenobarbital is very similar to primidone. Do not use medications containing primidone while using phenobarbital. Does BELLADONNA-PHENOBARBITAL interact with other drugs you are taking? Enter your medication into the WebMD interaction checker Check InteractionThe overdose of Phenobarbital-Hyoscyamine-Atropine-Scopolamine Oral: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: large pupils, hot/dry skin, fever, severe dizziness, severe drowsiness, severe thirst, mental/mood changes (such as confusion, unusual excitement), fast/irregular heartbeat, muscle weakness, inability to move (paralysis), slowed </s>