 <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]  effect. Phenobarbital belongs to a class of drugs known as barbiturate sedatives. How to use BELLADONNA-PHENOBARBITAL Take this medication by mouth as directed by your doctor. If you are taking the immediate-release tablets or liquid form of this medication, take it as directed by your doctor, usually 3 to 4 times a day. If you are using the liquid, carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose. If you are taking the extended-release tablets, take them as directed by your doctor, usually every 12 hours. Do not crush or chew extended-release tablets. Doing so can release all of the drug at once, increasing the risk of side effects. Swallow the whole tablet without crushing or chewing. Antacids lower the absorption of this medication. If you are taking an antacid, take it at least 2 hours apart from this medication. The dosage is based on your medical condition and response to treatment. In children, the dosage is also based on weight. Do not increase your dose or take this drug more often without your doctor's approval. Your condition will not improve any faster and the risk of serious </s>