Phentermine is a sympathomimetic amine, like amphetamine, which is one of the most often prescribed drugs for weight loss. Although exact mechanism of phentermine causing psychosis is still not clear, numerous reports already showed that phentermine can induce psychosis. Psychotic symptoms are generally resolved once the medications are stopped. In contrast, we present a case of a 25-years-old Asian female patient who developed psychotic symptoms repeatedly after phentermine administrations. This case suggests that phentermine can cause psychotic episodes repeatedly, resulting in chronic occupational and social impairment. Therefore, a precautious measure such as government regulations for physicians prescribing and an education for patients taking phentermine are urgently needed.
Amphetamine ; Asian Continental Ancestry Group ; Education ; Female ; Government Regulation ; Humans ; Phentermine ; Psychotic Disorders ; Recurrence ; Weight Loss

OBJECTIVES: A retrospective case series study was conducted to investigate the clinical characteristics of psychotic disorders induced by appetite suppressants, phentermine and phendimetrazine. METHODS: A retrospective electronic medical record review identified 5 admitted patients who had psychotic symptoms after taking phentermine or phendimetrazine. Clinical information was reviewed and summarized in each case. RESULTS: Hallucinations were reported in all cases, including auditory, visual, olfactory and somatic hallucinations. After discontinuation of phentermine or phendimetrazine, the symptoms rapidly improved with low dose of antipsychotics. Patients tended to have less prominent negative symptoms and higher insight into illness, and often showed depressive mood. These clinical characteristics were similar to psychosis induced by amphetamines. Two patients developed stimulant use disorder while using phentermine. CONCLUSIONS: These findings call for awareness of the risks associated with use of appetite suppressants. Prescription of phentermine or phendimetrazine should be accompanied by close monitoring of mental status, and suspicion for substance/medication-induced psychotic disorder.
Amphetamines ; Antipsychotic Agents ; Appetite Depressants* ; Appetite* ; Electronic Health Records ; Hallucinations ; Humans ; Phentermine* ; Prescriptions ; Psychotic Disorders* ; Retrospective Studies ; Substance-Related Disorders

We present a case report indicating that the administration of phentermine, an appetite suppressant with sympathomimetic activity, can provoke an intracerebral hemorrhage. A 48-year-old woman with no previously established cerebrovascular risk fa ctors and who had taken phentermine for 30 days developed sudden-onset left hemiparesis. Brain magnetic resonance imaging revealed an acute intracerebral hemorrhage involving the right thalamus. This case indicates that physicians should be aware of the relevant cause of medication history including appetite suppressants in young patients with an acute intracerebral hemorrhage.
Appetite Depressants ; Appetite* ; Brain ; Cerebral Hemorrhage* ; Female ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Paresis ; Phentermine* ; Thalamus

There have recently been many advances in obesity treatment, including lifestyle modifications and pharmacological and surgical treatments. Specifically, pharmacological strategies have improved significantly. However, the history of the development of medications aimed at weight loss is complicated. The Federal Drug Administration (FDA) withdrew anti-obesity drugs such as fenfluramine, dexfenfluramine, and phenylpropylamine due to their unwanted side effects. Moreover, sibutramine was voluntarily withdrawn from the market and a new drug, rimonabant, has been suspended in the middle of a clinical trial due to unacceptable side effects. The FDA has approved four new anti-obesity drugs in recent years. Lorcaserin is a selective 5-hydroxytryptamine receptor 2c (5-HT2c) agonist. The pharmacological mechanism of action of this drug is similar to fenfluramine and dexfenfluramine, but lorcaserin is specific for 5-HT2c, which are located almost exclusively in the central nervous system and are not found in heart valves. Three phase 3 clinical trials for lorcaserin have been published recently; weight reduction was successful and no side effects involving the heart were found. Furthermore, the FDA has also approved phentermine/topiramate controlled-release (PHEN/TPM CR), which is composed of a combination of immediate-release phentermine and controlled-release topiramate. Weight reduction achieved with PHEN/TPM CR was demonstrated to be better than all other anti-obesity drugs. Lastly, the combination therapy bupropion/naltrexone activates proopiomelanocortin neurons and inhibits opioid-mediated negative feedback by synergism. Similar to liraglutide, a long-acting analogue of the hormone glucagon-like peptide-1, this treatment showed significant weight loss and metabolic improvements. However, in addition to its efficacy, clinicians should consider its side effects before use.
Anti-Obesity Agents ; Central Nervous System ; Dexfenfluramine ; Fenfluramine ; Glucagon-Like Peptide 1 ; Heart ; Heart Valves ; Life Style ; Neurons ; Obesity* ; Phentermine ; Pro-Opiomelanocortin ; Serotonin ; Weight Loss ; Liraglutide

According to WHO global estimates from 2008, more than 1.4 billion adults were overweight and among them, over 200 million men and 300 million women were obese. Although the main treatment modalities for overweight and obese individuals remain dieting and physical exercise, the synthetic anti-obesity medications have been increasingly used due to their perceived convenience. Generally, anti-obesity medications are classified as appetite suppressants or fat absorption blockers. In the present study, we examined the adverse side-effects in respect of behavior changes of phentermine and Ephedra sinica (mahuang) that are anti-obesity drugs currently distributed to domestic consumers. Phentermine is mainly classified as an anorexing agent and mahuang a thermogenic agent. Because phentermine and mahuang are considered to display effectiveness through the regulation of nerve system, their potential influences of on behavioral changes were examined employing animal experiments. From the results of experiments testing locomotor activity through the use of treadmill, rota-rod, and open field system, phentermine and mahuang were commonly revealed to induce behavioral changes of rats by reducing a motor ability, an ability to cope with an external stimulus, and a sense of balance or by augmenting wariness or excitement. These adverse effects of phenternime and mahuang in behavioral changes need to be identified in humans and anti-obesity medications such as phentermine and mahuang should be prescribed for only obesity where it is anticipated that the benefits of the treatment outweigh their potential risks.
Absorption ; Adult ; Animal Experimentation ; Animals ; Anti-Obesity Agents* ; Appetite Depressants ; Diet ; Diethylpropion ; Ephedra sinica ; Exercise ; Female ; Humans ; Male ; Models, Animal* ; Motor Activity ; Obesity ; Overweight ; Phentermine* ; Rats ; Rats, Sprague-Dawley*

Phentermine has been widely used as an appetite suppressant since 2004 in Korea. The authors experienced two cases of acute phentermine overdose and report with the literature review. A 36-year-old man and a 24-year-old woman presented together to the emergency department with taking 13 tablets (390 mg) of phentermine 16 hours ago. They had tachycardia, hypertension and complained visual symptoms, nausea, insomnia and anxiety. These symptoms were resolved by conservative management.
Adult ; Anxiety ; Appetite ; Drug Overdose ; Emergency Service, Hospital ; Female ; Humans ; Hypertension ; Korea ; Nausea ; Phentermine* ; Sleep Initiation and Maintenance Disorders ; Tablets ; Tachycardia ; Young Adult

Phentermine has been widely used as an appetite suppressant since 2004 in Korea. The authors experienced two cases of acute phentermine overdose and report with the literature review. A 36-year-old man and a 24-year-old woman presented together to the emergency department with taking 13 tablets (390 mg) of phentermine 16 hours ago. They had tachycardia, hypertension and complained visual symptoms, nausea, insomnia and anxiety. These symptoms were resolved by conservative management.
Adult ; Anxiety ; Appetite ; Drug Overdose ; Emergency Service, Hospital ; Female ; Humans ; Hypertension ; Korea ; Nausea ; Phentermine* ; Sleep Initiation and Maintenance Disorders ; Tablets ; Tachycardia ; Young Adult

Obesity is an important risk factor for metabolic disease and various cancers. Treatments of obesity include lifestyle intervention, pharmacotherapy, and bariatric surgery. If weight loss with lifestyle intervention is only modest, pharmacotherapy might be needed. Pharmacotherapy agents can be grouped by treatment period as short term or long term use agent. Several sympathomimetic drugs such as benzphetamine, diethylpropion, phendimetrazine and phentermine, are approved for short term treatment due to their safety issues. For long term treatment, orlistat, lorcaserin, and combination of phentermine/topiramate are approved by U.S. Food and Drug Administration (FDA). Orlistat partially blocks intestinal digestion of fat, therefore producing weight loss. Lorcaserin is a serotonin 2C receptor agonist. The combination of phentermine/topiramate produces a mean weight loss of 8-10 kg. Side effects of each drug are quite different. For obesity patient, side effects are important factor when choosing drugs. The goal of this article is to review currently available anti-obesity drugs.
Anti-Obesity Agents ; Bariatric Surgery ; Benzphetamine ; Diethylpropion ; Digestion ; Drug Therapy* ; Humans ; Life Style ; Metabolic Diseases ; Obesity* ; Phentermine ; Receptor, Serotonin, 5-HT2C ; Risk Factors ; Sympathomimetics ; United States Food and Drug Administration ; Weight Loss

A safe and effective way to control weight in patients with affective disorders is needed, and phentermine is a possible candidate. We performed a PubMed search of articles pertaining to phentermine, sibutramine, and affective disorders. We compared the studies of phentermine with those of sibutramine. The search yielded a small number of reports. Reports concerning phentermine and affective disorders reported that i) its potency in the central nervous system may be comparatively low, and ii) it may induce depression in some patients. We were unable to find more studies on the subject; thus, it is unclear presently whether phentermine use is safe in affective disorder patients. Reports regarding the association of sibutramine and affective disorders were slightly more abundant. A recent study that suggested that sibutramine may have deleterious effects in patients with a psychiatric history may provide a clue for future phentermine research. Three explanations are possible concerning the association between phentermine and affective disorders: i) phentermine, like sibutramine, may have a depression-inducing effect that affects a specific subgroup of patients, ii) phentermine may have a dose-dependent depression-inducing effect, or iii) phentermine may simply not be associated with depression. Large-scale studies with affective disorder patients focusing on these questions are needed to clarify this matter before investigation of its efficacy may be carried out and it can be used in patients with affective disorders.
Anti-Obesity Agents ; Central Nervous System ; Cyclobutanes ; Depression ; Humans ; Mood Disorders ; Obesity ; Phentermine

Obesity is associated with a reduction in life expectancy and an increase in mortality from cardiovascular diseases, cancer, and other causes. The U.S. Preventive Service Task Force (USPSTF) recommends screening all adults for obesity. Clinicians should offer or refer patients with a body mass index of 30 kg/m2 or higher to intensive, multicomponent behavioral interventions. Behavioral interventions can lead to a moderate weight loss and improvement in blood sugar and other risk factors for cardiovascular disease. Behavioral interventions decreased the incidence of diabetes diagnosis by about 50% over 2 to 3 years. Orlistat, phentermine, diethylpropion, phendimetrazine, mazindol have been approved as anti-obesity drugs by Korea Food and Drug Administration. The U.S. Food and Drug Administration approved lorcaserin and phentermine plus topiramate combination for treatment of obesity in 2012.
Adult ; Advisory Committees ; Anti-Obesity Agents ; Benzazepines ; Blood Glucose ; Body Mass Index ; Cardiovascular Diseases ; Diethylpropion ; Fructose ; Humans ; Incidence ; Korea ; Lactones ; Life Expectancy ; Mass Screening ; Mazindol ; Morpholines ; Obesity ; Phentermine ; Risk Factors ; United States Food and Drug Administration ; Weight Loss