Phentermine Vs. Vyvanse: Drug Comparison

Phentermine is the active ingredient in brand-name medications including Adipex-P^®. The information below is about brand name Adipex-P. According to the FDA, “Generic medicines use the same active ingredients as brand-name medicines and work the same way, so they have the same risks and benefits as the brand-name medicines.”

Adipex-P (phentermine hydrochloride) is a prescription medication used as a short-term adjunct to weight loss in patients with obesity. It works as an appetite suppressant by stimulating the central nervous system, which increases heart rate and blood pressure while reducing hunger. Adipex-P is typically prescribed alongside a reduced-calorie diet and exercise regimen to enhance weight loss efforts. Common side effects include increased heart rate, dry mouth, insomnia, and nervousness. It is important to note that Adipex-P is intended for short-term use due to the potential for dependence and other adverse effects​.

Vyvanse^® (lisdexamfetamine) is a stimulant medication used to treat attention-deficit hyperactivity disorder (ADHD) and binge eating disorder (BED) by increasing available levels of dopamine and norepinephrine in the brain, which helps improve focus, attention, and impulse control. Its FDA-approved indications include the treatment of ADHD in patients 6 years and older and moderate to severe binge eating disorder in adults. Vyvanse is available in capsule and chewable tablet forms, typically taken once daily in the morning. Common side effects include decreased appetite, insomnia, dry mouth, and increased heart rate, with serious risks including potential cardiovascular issues and psychiatric side effects like anxiety. Vyvanse carries a boxed warning for the high risk of abuse, dependence, and serious cardiovascular events, particularly in individuals with a history of heart problems.

Sympathomimetic amine anorectic

Central nervous system (CNS) stimulant

Adipex-P (phentermine hydrochloride) is indicated:

• As a short-term adjunct (a few weeks) in a regimen of weight reduction based on exercise, behavioral modification and caloric restriction in the management of exogenous obesity for patients with an initial body mass index greater than or equal to 30 kg/m², or greater than or equal to 27 kg/m² in the presence of other risk factors (e.g., controlled hypertension, diabetes, hyperlipidemia)

Vyvanse (lisdexamfetamine dimesylate) is indicated for the treatment of:

• Attention deficit hyperactivity disorder (ADHD) in adults and pediatric patients 6 years and older

• Moderate to severe binge eating disorder (BED) in adults

• Typically taken orally once daily

• Comes in 37.5 mg tablets

• Typically taken orally once daily

• Comes in 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, and 70 mg capsules and 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, and 60 mg chewable tablets

Adverse events have been reported in the following systems:

• Cardiovascular

• Central nervous system

• Gastrointestinal

• Allergic

• Endocrine

Most common adverse reactions (incidence ≥5% and at a rate at least twice placebo) in pediatric patients ages 6 to 17 years, and/or adults with ADHD were:

• Anorexia

• Anxiety

• Decreased appetite

• Decreased weight

• Diarrhea

• Dizziness

• Dry mouth

• Irritability

• Insomnia

• Nausea

• Upper abdominal pain

• Vomiting

Most common adverse reactions (incidence ≥ 5% and at a rate at least twice placebo) in adults with BED were:

• Dry mouth

• Insomnia

• Decreased appetite

• Increased heart rate

• Constipation

• Feeling jittery

• Anxiety

• History of cardiovascular disease (e.g., coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension)

• During or within 14 days following the administration of monoamine oxidase inhibitors

• Hyperthyroidism

• Glaucoma

• Agitated states

• History of drug abuse

• Pregnancy

• Nursing

• Known hypersensitivity, or idiosyncrasy to the sympathomimetic amines

• Drug interactions: Monoamine oxidase inhibitors, alcohol, insulin and oral hypoglycemics, adrenergic neuron blocking drugs

• Known hypersensitivity to amphetamine products or other ingredients in Vyvanse

• Use with monoamine oxidase (MAO) inhibitor, or within 14 days of the last MAO inhibitor dose

• Drug interactions: Acidifying and alkalinizing agents

• Coadministration with other drugs for weight loss is not recommended

• Rare cases of primary pulmonary hypertension have been reported

• Rare cases of serious regurgitant cardiac valvular disease have been reported

• Tolerance to the anorectic effect usually develops within a few weeks

• Adipex-P may impair the ability of the patient to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle

• Risk of abuse and dependence

• Concomitant alcohol use may result in an adverse drug reaction

• Use caution in patients with even mild high blood pressure

• A reduction in dose of insulin or oral hypoglycemic medication may be required in some patients

• Breastfeeding: Discontinue drug or nursing taking into consideration importance of drug to mother

• Risks to patients with serious cardiac disease

• Increased blood pressure and heart rate

• Long-term suppression of growth in pediatric patients

• Peripheral vasculopathy, including Raynaud's phenomenon

• Serotonin syndrome

• Motor and verbal tics, and worsening of Tourette's syndrome

• Pregnancy: May cause fetal harm

• Breastfeeding: Breastfeeding not recommended

WARNING: ABUSE, MISUSE, AND ADDICTION

Vyvanse has a high potential for abuse and misuse, which can lead to the development of a substance use disorder, including addiction. Misuse and abuse of CNS stimulants, including Vyvanse, can result in overdose and death:

• Before prescribing Vyvanse, assess each patient's risk for abuse, misuse, and addiction.

• Educate patients and their families about these risks, proper storage of the drug, and proper disposal of any unused drug.

• Throughout treatment, reassess each patient's risk and frequently monitor for signs and symptoms of abuse, misuse, and addiction.

*This information is from the label for brand name Adipex-P^®. See the Full Prescribing Information for more complete information. Phentermine, the active ingredient in Adipex-P, may also be the active ingredient in other medications, and this information may not be accurate for all medications that include the active ingredient phentermine.

*This information is from the label for brand name Vyvanse^®. See the Full Prescribing Information for more complete information. Lisdexamfetamine, the active ingredient in Vyvanse, may also be the active ingredient in other medications, and this information may not be accurate for all medications that include the active ingredient lisdexamfetamine.