Psychotic Disorder Induced by Appetite Suppressants, Phentermine or Phendimetrazine: A Case Series Study

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.

A Case of Phendimetrazine Induced-Psychotic Disorder and Dependence / 신경정신의학

Phendimetrazine and related amphetamine-like compounds are used widely as appetite suppressants in Korea. We report on a patient who developed psychotic disorder and dependence while using phendimetrazine. A 25-year-old female with no psychiatric history began experiencing hallucination of bugs after using phendimetrazine for weight loss for five months. She was admitted and the drug was stopped. Three days later, her psychotic symptoms had subsided and she returned home. Two months after discharge, against medical advice, she returned to a clinic to obtain phendimetrazine for its anorectic effect. She continued using phendimetrazine because she had developed withdrawal symptoms and experienced cravings for it. Within two months of restarting the drug, she had developed paranoid delusions, auditory and olfactory hallucinations. She was readmitted, and was confirmed to have a dependence on phendimetrazine. This case provides a warning that amphetamine-related anorectics can cause psychotic disorder and dependence.

Two Cases of Ocular Complications Caused by Phendimetrazine

PURPOSE: The authors of the present study report treatment experience of acute myopia and branch retinal vein occlusion associated with phendimetrazine, a drug used for weight reduction. CASE SUMMARY: Case 1: A 32-year-old woman, previously devoid of ocular problems, visited our hospital with bilateral visual disturbance after taking phendimetrazine for weight reduction. Ciliochoroidal effusion and anterior shifting of the lens-iris diaphragm were observed, which resulted in a shallow anterior chamber, myopic shifting and an increase in intraocular pressure due to angle closure. The symptoms were relieved by discontinuing the use of phendimetrazine and administration of intraocular pressure-lowering agents. Case 2: A 26-year-old woman, previously devoid of ocular problems, visited our hospital with left superior visual field disturbance after taking phendimetrazine for weight reduction. The examinations revealed papilledema, disc hemorrhage and tortuous vascular changes in her left eye. Fluorescein angiography was performed, and retinal vein occlusion was diagnosed. The patient discontinued weight reduction agents and recovered while under observation. CONCLUSIONS: Phendimetrazine, used for weight reduction, can cause acute myopia via prostaglandin synthesis and retinal venous occlusion due to vascular constriction.

Two Cases of Psychotic Disorder Following Phendimetrazine Use / 대한정신약물학회지

Phendimetrazine is a medication currently being used to help patients with weight loss. It shares a chemical structure with amphetamines. As such, it shares some of the same toxicities, which can include psychosis. Two cases present good examples of phendimetrazine-induced psychotic disorder. A 30-year old female was admitted to emergency room with visual hallucination, auditory hallucination and aberrant behavior. Another 38-year old housewife was accompanied by her family to evaluate mood swing, auditory hallucination and behavioral change to psychiatric clinic. After evaluation in psychiatric ward, they were confirmed to have causal relation with prescription diet pills. These case reports demonstrate the potential dangers of amphetamine based diet pills. There have been several cases of cardiomyopathies and pulmonary hypertension related to phendimetrazine, but psychosis is something that is rarely recognized in an outpatient setting. Two cases showed the importance of obtaining a careful medication history in all patients and specially recognizing diet pills with an amphetamine base causing psychosis.

Gene Expression Profiling in C57BL/6 Mice Treated with the Anorectic Drugs Sibutramine and Phendimetrazine and Their Mechanistic Implications

Recently, obesity has become a worldwide public health concern and the use of anorectic drugs has drastically increased. In this study, sibutramine and phendimetrazine, representative marketed anorectics, were repeatedly administered per os on a daily basis into C57BL/6 mice and the effects of these drugs on food intakes, body weight changes and gene expression profiles were monitored for up to following 7 days. Methamphetamine, which has a potent anorectic effect, was used as a positive control. Anorectic effects were sustained only for two days by phendimetrazine or methamphetamine, but for six days by sibutramine. The modulations of gene expressions in the hypothalamus and the striatum were investigated using microarrays on day 2 and day 7 post-administration, which corresponded to the anorectic period and a return of appetite respectively, for all three drugs tested. Differences in overall gene expression profiles in the stratum on day 2 for sibutramine and phendimetrazine seems to reflect difference between the two in terms of the onsets of drug tolerance. According to microarray findings, the Ankrd26 gene appears to have an important anorectic role, whereas the up-regulation of the olfaction system appeared to be involved in the drug tolerance of anorectics. The microarray data presented in this study demonstrates the usefulness of gene expression analysis for gathering information on the efficacy and safety of anorectic drugs.

A Case of Ischemic Stroke Associated with Phendimetrazine as an Appetite Suppressant

The published case series have suggested that appetite suppressants had some association with the development of stroke. Phendimetrazine is an appetite suppressant with sympathomimetic activity and it has a similar chemical structure with amphetamines. We report that a 22-year-old woman who had taken phendimetrazine for one month developed sudden right homonymous hemianopsia. MRI showed acute infarction in the territory of left posterior cerebral artery (PCA). Phendimetrazine should be considered as a cause of ischemic stroke.