Drug treatment for obesity: Types, effects, and side effects of appetite suppressants

The main treatment for simple obesity is to consistently control food intake and exercise over the long term, rather than relying on medication. If one relies on or abuses medication to lose weight and abandons dieting and exercise, weight loss will often fail.

Furthermore, long-term use of medication inevitably leads to drug dependence or adverse reactions. Weight loss drugs can only be added when dietary therapy fails to work, or when obese individuals also suffer from peptic ulcers and find it difficult to adhere to dietary control treatment.

The types of weight loss drugs are described below.

I. Appetite suppressants

This is a drug that reduces weight by suppressing appetite and decreasing food intake.

It can be divided into:

(a) Amphetamine-type appetite suppressants.

These drugs can cause the hypothalamus and diencephalon to release monoamines such as dopamine, norepinephrine, and serotonin.

Monoamines can stimulate the satiety center, reducing appetite. Because the central effects of these drugs are similar to those of adrenaline, side effects such as insomnia, anxiety, palpitations, rapid pulse, high blood pressure, dry mouth, sweating, nausea, and vomiting may occur, and they are also addictive.

Patients with glaucoma should not use this type of medication because it has a pupil-dilating effect.

Patients using monoamine oxidase inhibitors should also avoid these drugs, as combined use may cause a hypertensive crisis.

Among these drugs, amphetamine has the most severe side effects, so it has no practical value in clinical practice. Amphetamine is now banned as an appetite suppressant in other countries.

Currently, pharmacologists have prepared a series of amphetamine derivatives based on years of research, with the aim of reducing its side effects and making it safer to use.

The discovery of fenfluramine is a new development in weight-loss drugs.

Fluphenazine is a commonly used weight-loss drug.

It can promote the release of serotonin from central neurons, stimulate the hypothalamic satiety center, and reduce appetite.

This drug can also increase the sensitivity of peripheral tissues to insulin and promote the absorption and utilization of glucose by tissues such as muscles.

Fluoroamphetamine has a significant effect on lipoprotein metabolism, reducing serum total cholesterol (CH), triglycerides (TG), low-density lipoprotein cholesterol (LDL-CH), total apolipoprotein β, and LDL apolipoprotein β, while increasing high-density lipoprotein (HDL), phospholipids, and high-density lipoprotein cholesterol (HDL-CH). It lowers the LDL-CH/HDL-CH ratio, which leads to atherosclerosis, while increasing the HDL-CH/LDL+ VLDL-CH ratio, which has anti-atherosclerotic properties.

This drug not only fails to activate catecholamines, but also inhibits dopamine activity due to the presence of serotonin in the brain. Therefore, it has no central nervous system excitation side effects and has a calming effect, which can lower blood pressure.

Therefore, this medicine is suitable for obese individuals with hypertension, coronary heart disease, diabetes, and hyperlipidemia.

Each tablet of fluorometholone contains 20 mg. Initially, take one tablet twice daily before meals, with an 8-hour interval between doses. Alternatively, take one tablet three times daily.

If weight loss is not significant, the dosage can be increased to 2 tablets per dose, which is up to 120 mg per day.

Side effects of this drug include drowsiness, depression, nausea, and diarrhea.

Since these side effects often occur after sudden discontinuation of the medication, the dosage should be gradually reduced after weight loss from taking the medication, and the medication should never be stopped abruptly.

Fluphenazine can worsen symptoms in patients with depression, therefore it should be avoided.

(ii) Other synthetic appetite suppressants.

These drugs do not contain amphetamine in their structure, but their pharmacological effects are similar to those of amphetamine.

Commonly used drugs in this category include diethylpropion and mazindol.

Choice of appetite suppressants: Currently, fluoroamphetamine, diethylamine benzophenone, and chlorpheniramine indole are commonly used.

Fluoropropylamine is particularly suitable for obese individuals with diabetes, as well as obese individuals who are particularly stressed or irritable.

Diethylamine benzophenone has fewer side effects and the same weight-reducing effect as clofenacindo, but the former is cheaper and can be used as the first-line drug.

Fluoropropylamine and diethylamine benzophenone have a blood pressure-lowering effect on patients with hypertension, so they are suitable for obese people with hypertension.

Both diethylamine benzophenone and chlorpheniramine indole theoretically have a mild blood pressure-raising effect, but their blood pressure-lowering effect during weight loss far outweighs their mild blood pressure-raising effect.

Therefore, these medications can be safely used in patients with hypertension; however, blood pressure changes should still be carefully monitored.

This drug is contraindicated in patients who have already been treated with guanethidine, methyldopa, guanethidine, or phenylguanidine.