Brompheniramine tablets generally work best for patients with myasthenia gravis who need to take them for several months or even years, and for patients with functional post-surgical flatulence and urinary retention who generally take them for a few hours to a few days. However, the exact duration of the medication depends on the patient’s condition. Patients with myasthenia gravis usually need to take brompheniramine tablets for a long time for treatment and symptomatic relief, so the time to achieve the best effect after using the medicine will be relatively long, which may be months or even years. On the other hand, the use of brompheniramine tablets in patients with post-surgical functional flatulence and urinary retention is usually temporary, and therefore the medication is usually discontinued on medical advice once the symptoms have disappeared, and therefore the time to achieve the best results from the use of the medication will be relatively shorter, usually from a few hours to a few days. Brompheniramine peaks at about 1 to 5 hours after oral administration and the half-life of the drug is about 3.3 hours. Common side effects of this product include diarrhea, nausea, vomiting, increased sweating, and frequent urination. There is a risk of psychiatric abnormalities if too much of the drug is used. It is contraindicated in the presence of previous angina pectoris, bronchial asthma, and mechanical intestinal obstruction. Brompheniramine tablets clinically need to determine the dosage of the drug according to the patient’s condition, and it is recommended that the drug should be taken orally in a standardized manner under the guidance of a doctor.