Anorectic efficacy and safety of the diethylpropion-topiramate combination in rats

Combination of diethylpropion with dietary intervention results in body weight and fat loss with preserved muscle mass in obese patients

Combining pharmacotherapy with lifestyle intervention is recommended for obese class II patients who fail lifestyle therapy and for obese class I patients. Diethylpropion, an obesity medication, has been approved for use in Indonesia, which is an Asia-Pacific country. This retrospective study aimed to assess the short-term effects of diethylpropion on weight and fat loss in obese patients in Indonesia. Secondary data were collected from 142 patients' medical records with a body mass index ≥ 25 kg/m2 who underwent short-term diethylpropion treatment for 84 days between January 2022 and November 2023 at the Kimia Farma Nutrition Clinic in Bandung, Indonesia. Blood pressure, body weight, height, waist circumference, and body composition were assessed at each follow-up visit to determine the fat and muscle mass. Patients were prescribed diethylpropion 25 mg 3 times daily every 2 weeks together with dietary intervention. Kruskal-Wallis test was used to analyze the changes in body weight, skeletal muscle, fat mass, and waist circumference after the diethylpropion therapy. Mann-Whitney test was used for the relation between age, sex, and body mass index with weight loss on the last day of follow-up. Simple linear regression analysis was also performed to identify the correlation between weight loss and therapy duration. This study showed body weight reduction of up to 9.5 ± 3 kg (10 ± 0.0%) (P = .008) on 84 days of treatment. Significant fat loss 11.5 ± 4.6 kg (20.5 ± 0.0%) (P = .005) was also reported in our study without significant loss of muscle mass -2.4 ± 4.6 kg (3.6 ± 1.3%) (P = .58). Waist circumference was insignificantly reduced by 5.6 ± 0.0 cm (4.9 ± 2.8%) (P = .21) after 84 days of diethylpropion therapy. This study revealed no significant changes in patient systolic and diastolic pressures despite showing mild increases after 70 days. The combination of diethylpropion and an appropriate diet resulted in weight loss accompanied by significant fat loss and preserved muscle mass without an increase in blood pressure during the 12-week treatment period.

Pharmacological Treatments and Natural Biocompounds in Weight Management

The obesity pandemic is one of society’s most urgent public health concerns. One-third of the global adult population may fall under obese or overweight by 2025, suggesting a rising demand for medical care and an exorbitant cost of healthcare expenditure in the coming years. Generally, the treatment strategy for obese patients is largely patient-centric and needs dietary, behavioral, pharmacological, and sometimes even surgical interventions. Given that obesity cases are rising in adults and children and lifestyle modifications have failed to produce the desired results, the need for medical therapy adjunct to lifestyle modifications is vital for better managing obesity. Most existing or past drugs for obesity treatment target satiety or monoamine pathways and induce a feeling of fullness in patients, while drugs such as orlistat are targeted against intestinal lipases. However, many medications targeted against neurotransmitters showed adverse events in patients, thus being withdrawn from the market. Alternatively, the combination of some drugs has been successfully tested in obesity management. However, the demand for novel, safer, and more efficacious pharmaceutical medicines for weight management does exist. The present review elucidates the current understanding of the available anti-obesity medicines of synthetic and natural origin, their main mechanisms of action, and the shortcomings associated with current weight management drugs.

Anorectic interaction and safety of 5-hydroxytryptophan/carbidopa plus phentermine or diethylpropion in rat

Drug combinations are being studied as potential therapies to increase the efficacy or improve the safety profile of weight loss medications. This study was designed to determine the anorectic interaction and safety profile of 5-hydroxytryptophan (5-HTP)/carbidopa + diethylpropion and 5-HTP/carbidopa + phentermine combinations in rats. The anorectic effect of individual drugs or in combination was evaluated by the sweetened milk test. Isobologram and interaction index were employed to determine the anorectic interaction between 5-HTP/carbidopa and diethylpropion or phentermine. Plasma serotonin (5-HT) was measured by ELISA. Safety of repeated doses of both combinations in rats was evaluated using the tail sphygmomanometer, cardiac ultrasound, hematic biometry and blood chemistry. A single oral 5-HTP, diethylpropion or phentermine dose increased the anorectic effect, in a dose-dependent fashion, in 12 h-fasted rats. A dose of carbidopa at 30 mg/kg reduced the 5-HTP-induced plasmatic serotonin concentration and augmented the 5-HTP-induced anorectic effect. Isobologram and interaction index indicated a potentiation interaction between 5-HTP/30 mg/kg carbidopa + diethylpropion and 5-HTP/30 mg/kg carbidopa + phentermine. Chronic administration of experimental ED40 of 5-HTP/30 mg/kg carbidopa + phentermine, but not 5-HTP/30 mg/kg carbidopa + diethylpropion, increased the mitral valve leaflets area. Moreover, there were no other significant changes in cardiovascular, hematic or blood parameters. Both combinations induced around 20% body weight loss after 3 months of oral administration. Results suggest that 5-HTP/30 mg/kg carbidopa potentiates the anorectic effect of diethylpropion and phentermine with an acceptable safety profile, but further clinical studies are necessary to establish their therapeutic potential in the obesity treatment.