In a scientific review article published this year in the journal of Vascular Health and Risk Management the authors conclude: "Sibutramine, in conjunction with lifestyle measures, is a useful drug for reducing body weight and improving
associated cardiometabolic risk factors and obesity-related disorders."
Studies have shown that sibutramine enhances the weight loss effect of calorie restricted diets. That means that sibutramine plus diet and exercise results in greater weight loss than diet and exercise alone.
Currently (Dec 2009), sibutramine and orlistat are the only two anti-obesity medications approved for long-term use. Sibutramine reduces appetite whereas orlistat prevents gastrointestinal fat absorption.
Sibutramine Side Effects
Studies report that side effects with sibutramine include dry mouth, constipation and headache.
A study by Johansson and colleagues published in the journal Obesity Reviews in December 2009 examined the blood pressure effects of current anti-obesity drugs, collecting data from a large number of previous studies conducted between 1990 and 2009. This meta-analysis revealed that in the studies using sibutramine at the normal approved doses, the drug caused significant elevations in diastolic blood pressure but it did not affect the systolic blood pressure.
Viner RM, who tested the efficacy and safety of anti-obesity drugs in children and adolescents concluded that "sibutramine improved waist circumference, triglycerides and high density lipoprotein (HDL)-cholesterol, but raised systolic and diastolic blood pressure and pulse."
Recent data indicate an increased risk of heart attack and stroke in patients with a history of cardiovascular disease using sibutramine. Based on that data new contraindications have been added. Sibutramine is not to be used in patients with a history of cardiovascular disease, including:
- History of coronary artery disease (e.g., heart attack, angina)
- History of stroke or transient ischemic attack (TIA)
- History of heart arrhythmias
- History of congestive heart failure
- History of peripheral arterial disease
- Uncontrolled hypertension (e.g., > 145/90 mmHg)
How Does Sibutramine Work To Reduce Weight?
In his paper published in the International Journal of Obesity, Dr MEJ Lean (University of Glasgow) explains that “Sibutramine offers three types of benefits in weight management: by enhancing weight loss, by improving weight maintenance and by reducing the comorbidities of obesity”.
The drug works by inhibiting the reuptake of neurotransmitters. What does this actually mean? Neurons communicate by releasing neurotransmitters, as explained in the video below. These are chemical molecules that are released from one neural cell and interact with receptors on the membrane of another neural cell. However, not all of these molecules actually interact with the receptors of the other cell. Some of them re-enter the neuron that secreted them. This re-uptake process controls the intensity of the signal that is transmitted from one neuron to another. If the re-uptake is inhibited, more neurotransmitter molecules get to interact with the receptors of the other neuron and thus the intensity of the signal transmitted is higher. Sibutramine blocks the reuptake of both serotonin (5-HT) and Nor-adrenaline (two neurotransmitters) and augments the stimuli to satiety in the hypothalamus.
(Note: Part of the information about the side effects of sibutramine presented in this article was kindly provided by Mrs Sue Widemark)