PHENTERMINE HCL and Benzphetamine are FDA-approved appetite suppressants, of a class known as sympathomimetic amines. Sympathomimetic amines activate the sympathetic nervous system to release norepinephrine, which is a neurotransmitter connected with managing food intake (therefore suppressing the appetite). Effectively, it tricks the patient’s brain into believing he or she has already eaten.
Phentermine HCL works in a similar way to amphetamines when it comes to reducing appetite and inducing a feeling of being full; however, unlike amphetamines, it does not significantly impact dopamine levels (lowering the risk of addiction and abuse). Benzphetamine, however, is somewhat more similar to amphetamines in nature and is classed as a Schedule III drug, meaning there is a slightly higher risk of addiction than with Phentermine HCL and it is, therefore, less commonly prescribed than Phentermine.
Because these drugs are associated with appetite suppression, they are also commonly referred to as “anorectics” or “anorexigens.” However, it is not known precisely how they work in relation to weight loss; it is possible that other metabolic or central nervous system effects from the drug may be driving these results.
Phentermine HCL and Benzphetamine are prescribed in combination with exercise and healthy diet. In clinical trials of Phentermine, the combination of medication, diet, and exercise has shown on average 3.6kg more in weight loss results when compared with a placebo. Phentermine is the most commonly prescribed medication in the US for the clinical treatment of obesity.
In addition to weight loss, other benefits of these medications are the reduction of health risks correlated with obesity, such as diabetes, heart disease, high blood pressure, and lower life expectancy.
The downsides of these medications are that over time, tolerance will be built up, and therefore they are not considered suitable for long-term usage.
Phentermine HCL vs Benzphetamine: What are the Differences?
Phentermine HCL is the most well-known treatment for obesity and is the weight loss medication most commonly prescribed by healthcare professionals in the United States. It is primarily recommended for heavily obese individuals who suffer from weight-related health issues such as cardiovascular problems, high blood pressure or cholesterol, diabetes, etc.
Phentermine HCL and Benzphetamine act in a similar way: suppressing appetite and managing cravings by altering signals from the central nervous system, stimulating heart rate and other vital functions which increases caloric burn, and speeding up the metabolism by affecting the gastrointestinal tract.
While Phentermine HCL and Benzphetamine do act similarly, they have different ingredients and also differ when it comes to how quickly and strongly they act and the way in which the dosage is applied. Phentermine is considered more potent for weight loss, so it is usually taken once per day and is not recommended to take more than twice daily (although a physician may adjust dosage and timings for the individual patient). In contrast, Benzphetamine can be taken 3-4 times daily, even with the same dosage.
Benzphetamine is closer to amphetamines than Phentermine HCL, and is, therefore, a higher risk for habit-forming and addiction. It can also lead to a positive result for amphetamine and methamphetamine in a urine drug screen. However, it is sometimes more effective than other diet drugs.
Common Side Effects of Phentermine HCL and Benzphetamine
Common side effects of Phentermine HCL and Benzphetamine may include insomnia, nervousness, dry mouth, constipation, irritability, restlessness, nausea, diarrhea, changes in libido and headaches. These drugs are also not recommended for patients with heart disease or hypertension. Regular blood pressure monitoring is important during treatment.
Some side effects may be more serious than others, and if experienced should be reported to a healthcare professional immediately. These include changes in mood or behavior, hallucinations or paranoia, chest pain, irregular or fast heartbeat, tremors, unusual levels of fatigue, seizures, fever, breathing problems, and allergic reactions like swelling, itching, skin rash or hives.
Sympathomimetic drugs by their nature act on the central nervous system, and this means that they can increase heart rate and blood pressure and increase the release of fatty acids and glycerol. In addition, these drugs do have potential to create addiction, particularly in patients who are susceptible to addictive substances. You should also inform your doctor before taking these medications if you have a history of mood disorders such as anxiety or depression.
Both Phentermine HCL and Benzphetamine are considered short-term prescriptions and usually are only prescribed for a few weeks at a time. They should not be taken with other appetite suppressants, as this can increase the potential for serious side effects. Long-term use of the medication also increases that risk. Taking Benzphetamine along with other diet pills (even OTC medicines) can cause pulmonary hypertension (a fatal, rare lung disorder).
However, stopping these medications suddenly can also lead to withdrawal symptoms, especially if usage has been long-term or high dosage. To prevent this, the prescribing doctor will often reduce the dose over time.
Some of the drug interactions to avoid include:
- Phenothiazines
- Other stimulants, including amphetamines and street drugs such as cocaine or MDMA
- Other appetite-suppressant drugs
- MAO inhibitors
- Insulin
- SSRIs
Caffeine and alcohol can also heighten adverse effects of these medications.
