Western medicine for weight loss: appetite suppressants, biguanides, and hormone drugs

Amphetamines and their derivatives

Benzyltoluamide: Pharmacological action: Inhibits the feeding center in the lateral hypothalamus; when used in conjunction with dietary therapy, it promotes metabolism and thermogenesis. Side effects: Nervousness, insomnia, headache, nausea, vomiting, tremors, hallucinations, tachycardia, and elevated blood pressure. Contraindicated in patients with atherosclerosis, hypertension, heart disease, hyperthyroidism, pregnant women, and children under 12 years of age. Dosage: 25-50 mg per dose, 1-3 times daily; maximum daily dose 150 mg.

Dextroamphetamine: Pharmacological effects are similar to benzylmethylamphetamine, with systemic stimulant effects, often used to treat obesity caused by diabetes. Side effects: dry mouth, blurred vision, headache, palpitations, sweating, increased blood pressure, nausea, vomiting, insomnia. Dosage: Initially, 2.5-10 mg orally 2-3 times daily, with a maximum dose of 20 mg twice daily.

In addition, there are methamphetamine and chlorpheniramine, with side effects similar to the previous two. Amphetamine drugs have significant side effects and are rarely used clinically as appetite suppressants; non-amphetamine drugs are more commonly used. Diethylphenylacetone and chlorpheniramine have similar pharmacological effects. Diethylphenylacetone must be used under the supervision of a doctor, with a dosage of 25 mg each time, 2-3 times a day, half an hour or 1 hour before meals; long-acting doses are 75-100 mg each time, once a day, with a general course of treatment of 1.5-2.5 months.

Indoles and their derivatives

Pharmacological effects: Promotes the release of neurotransmitters from nerve endings, inhibits the appetite center, promotes the utilization of glucose by muscle and fat tissues, lowers blood sugar, and reduces serum cholesterol and triglycerides. It is well absorbed orally, has few side effects, and has no effect on heart rate, liver, or kidney function.

Fluphenazine: A commonly used clinical drug for treating obesity. It has no excitatory effect on the nervous system and is not easily addictive. It is suitable for obese individuals with hyperlipidemia and diabetes. Common side effects include thirst, drowsiness, headache, depression, nausea, constipation, hair loss, hemolytic anemia, rash, and palpitations. Use with caution in patients with hypertension or cardiovascular disease; contraindicated in patients with depression. Dosage: 20 mg orally three times daily, 30 or 60 minutes before meals. The maximum dose is 40 mg three times daily. The usual course of treatment is 1.5-2.5 months, and should not exceed 5 months.

Chlorpheniramine maleate: Primarily acts on the limbic system of the hypothalamus, exhibiting significant appetite suppression with relatively minor central nervous system excitatory effects. Side effects: Dry mouth, fatigue, palpitations, and excitement. Use with caution in patients with hypertension or cardiovascular disease. Dosage: 1 mg orally three times daily, half an hour before meals, or 2 mg once daily.

Biguanide oral hypoglycemic agents

These types of drugs (phenformin, hypoglycemic tablets) can lower blood triglycerides and cholesterol, reduce weight, and suppress appetite. Because these drugs do not stimulate the release of insulin from pancreatic β-cells, they have no effect on blood sugar in normal individuals and can be taken by obese patients without diabetes. With dietary control, taking this drug results in a 25% weight loss compared to not taking it. These drugs can reduce weight in 80%-90% of obese patients. Side effects: anorexia, nausea, vomiting, metallic taste in the mouth, diarrhea in high doses, and malabsorption, severe lactic acidosis. Contraindicated in patients with heart failure, coma, acute infectious diseases, myocardial infarction, dehydration, blood loss, or hypovolemic shock. Dosage: Oral phenformin (phenformin), starting with 25 mg each time, 2-3 times daily, before meals. After three days, increase by 25 mg, then increase by 50 mg weekly for one week, reaching a daily dose of 250-300 mg or until gastrointestinal symptoms occur. Take metformin (hypoglycemic tablets) orally, starting with 250 mg three times a day after meals, increasing by 500 mg each week thereafter. Discontinue use if gastrointestinal symptoms occur after 4-6 weeks of treatment.

Hormone drugs

Hormonal weight loss drugs include thyroid hormones, human chorionic gonadotropins, and growth hormones.

Thyroid hormones: Secreted by the thyroid gland, they maintain normal metabolism and development. Pharmacological effects include promoting the metabolism of carbohydrates, proteins, fats, and water-electrolytes, accelerating the oxidation process in tissue cells, increasing oxygen consumption and heat production, and leading to weight loss. Overdose can increase protein breakdown and cause cardiovascular dysfunction; therefore, it is not recommended for treating simple obesity, but is mostly used to treat obesity caused by hypothyroidism. Side effects: palpitations, tremors, excessive sweating, insomnia, nausea, vomiting, diarrhea, fever, rapid and irregular pulse, and even angina pectoris and heart failure. Start with a low dose, generally 10 mg daily, increasing to 80-120 mg daily. Use with caution in patients with coronary atherosclerosis, angina pectoris, or myocardial infarction. Dosage: Oral thyroid tablets, 60 mg daily, divided into two doses. If there are no significant adverse reactions, increase to 120 mg daily after 3 days, then increase by 30 mg weekly. When the daily dose reaches 360 mg, reduce to a maintenance dose and maintain for 3-6 months. For oral administration of T₄, take 15 micrograms twice daily, increasing by 30 micrograms each week until reaching 150 micrograms daily. For oral administration of T₃, start with 10 micrograms twice daily, gradually increasing to 80-100 micrograms daily, divided into 2-3 doses.

Human chorionic gonadotropin (HCG): A low-calorie diet is recommended when using HCG for treatment, as it enhances efficacy. The dosage is 500-1000 units intramuscularly, 1-2 times per week. It is contraindicated in patients with reproductive system diseases. Long-term use is not recommended.

Medications that break down localized fat: Injecting isoproterenol, yohimbine, etc., into areas of fat accumulation can reduce localized fat. These are contraindicated in obesity caused by coronary heart disease, myocarditis, or hyperthyroidism. Other medications such as laxatives and diuretics are rarely used currently because they do not achieve the goal of reducing fat.