Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
PHENDIMETRAZINE TARTRATE vs ALEVE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Phendimetrazine is a sympathomimetic amine that acts as an appetite suppressant by stimulating the hypothalamus to release norepinephrine, leading to decreased food intake and increased energy expenditure. It is a prodrug that is metabolized to phenmetrazine, which is a potent central nervous system stimulant with amphetamine-like effects.
Naproxen, a nonsteroidal anti-inflammatory drug (NSAID), inhibits cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing prostaglandin synthesis. This leads to decreased inflammation, pain, and fever.
Management of exogenous obesity as a short-term adjunct (a few weeks) in a regimen of weight reduction based on caloric restriction,Off-label: treatment of obesity with comorbid conditions where weight loss is beneficial
Rheumatoid arthritis,Osteoarthritis,Ankylosing spondylitis,Juvenile arthritis,Tendonitis,Bursitis,Acute gout,Primary dysmenorrhea,Mild to moderate pain,Fever
Oral: 35 mg twice daily or three times daily, 1 hour before meals; extended-release: 105 mg once daily in the morning.
220 mg orally every 8 to 12 hours as needed; maximum 660 mg per day.
Terminal half-life 3-4 hours; clinical context: requires multiple daily dosing
Terminal elimination half-life is 12-17 hours; allows twice-daily dosing for steady-state concentrations.
Primarily metabolized in the liver via N-demethylation to its active metabolite, phenmetrazine. Other metabolites include phendimetrazine N-oxide and norphenmetrazine. CYP450 enzymes are involved, though specific isoforms not well characterized.
Naproxen is extensively metabolized in the liver primarily via CYP2C9 to 6-O-desmethyl naproxen, and less than 5% is excreted unchanged in urine.
Primarily renal (≥70% unchanged) with minor biliary/fecal elimination (<10%)
Renal (95% as unchanged drug and metabolites); biliary/fecal (5%)
10-15% bound to albumin
>99% bound to albumin; saturable at high concentrations.
2-3 L/kg; indicates extensive tissue distribution
0.16 L/kg; indicates distribution primarily in extracellular fluid.
Oral: approximately 80-90%
Oral: ~95%; immediate-release formulation.
Contraindicated in severe renal impairment (GFR < 30 m L/min). No specific dose adjustments for mild-moderate impairment; use with caution.
GFR 30-59 m L/min: reduce dose and avoid long-term use; GFR <30 m L/min: contraindicated.
Not recommended in Child-Pugh class B or C. Use with caution in mild impairment.
Child-Pugh class A: no adjustment; Child-Pugh class B or C: avoid use.
Not recommended for children under 12 years; safety and efficacy not established.
2-12 years: 2.5-5 mg/kg/dose orally every 8-12 hours; maximum 10 mg/kg/day. 12 years and older: same as adult.
Start at lower end of dosing range; monitor for increased sensitivity and cardiovascular effects.
Initiate at lowest effective dose (220 mg every 12 hours); maximum 440 mg per day; monitor renal function and GI bleeding risk.
Phendimetrazine is not approved for use in patients with a history of drug abuse or dependence. It has a high potential for abuse and may lead to dependence. Use caution in patients with cardiovascular disease or hypertension.
Nonsteroidal anti-inflammatory drugs (NSAIDs) cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal. This risk may increase with duration of use. Patients with cardiovascular disease or risk factors may be at greater risk. Naproxen is contraindicated for treatment of peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery. NSAIDs cause an increased risk of serious gastrointestinal adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events can occur at any time during use and without warning symptoms. Elderly patients and patients with a prior history of peptic ulcer disease or GI bleeding are at greater risk.
Increased risk of pulmonary hypertension and valvular heart disease; monitor for dyspnea, chest pain, or edema. Tolerance may develop; discontinue if tolerance occurs. May impair ability to perform hazardous tasks. Use with caution in patients with hypertension, diabetes, or glaucoma. Do not use with MAOIs or within 14 days of discontinuation.
Cardiovascular thrombotic events,Gastrointestinal bleeding, ulceration, and perforation,Hypertension,Heart failure and edema,Renal toxicity,Anaphylactoid reactions,Serious skin reactions (e.g., Stevens-Johnson syndrome),Hematologic toxicity (inhibition of platelet aggregation),Exacerbation of asthma,Hepatic effects,Pregnancy: avoid during third trimester
Hypersensitivity to phendimetrazine or any component of the formulation, advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, hyperthyroidism, glaucoma, agitated states, history of drug abuse, during or within 14 days of MAOI therapy
History of asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs,Peri-operative pain in the setting of CABG surgery,Advanced renal disease,History of gastrointestinal bleeding or perforation related to previous NSAID therapy,Active gastrointestinal bleed
Avoid alcohol and excessive caffeine (coffee, tea, energy drinks) as they may increase CNS stimulation and risk of side effects. Take with or without food; high-fat meals may delay absorption of extended-release formulations. Maintain a calorie-reduced diet as part of a comprehensive weight loss plan.
Avoid concurrent use of alcohol as it increases GI bleeding risk. No specific food restrictions; taking with food or milk may reduce dyspepsia. High potassium foods (e.g., bananas, spinach) may increase hyperkalemia risk in patients with renal impairment.
First trimester: Limited data; potential for increased risk of oral clefts. Second/third trimester: Anorexiant effects may cause fetal growth restriction; avoid use due to maternal hypertension risk.
First trimester: Risk of spontaneous abortion and cardiac defects (odds ratio 1.86 for NSAIDs). Second trimester: Possible fetal renal dysfunction and oligohydramnios; ductus arteriosus premature closure risk begins. Third trimester: High risk of premature closure of ductus arteriosus, oligohydramnios, necrotizing enterocolitis, intracranial hemorrhage, and renal impairment; avoid after 30 weeks.
Excreted in breast milk; M/P ratio unknown. Contraindicated in breastfeeding due to potential CNS stimulation and cardiovascular effects in infant.
Excreted in breast milk in low concentrations (M/P ratio ~0.12); relative infant dose <1% of maternal weight-adjusted dose. Compatible with breastfeeding; monitor infant for potential adverse effects (gastrointestinal upset, rash) at higher doses.
Contraindicated in pregnancy; no dose adjustments recommended. Avoid use due to risks of hypertension and potential teratogenicity.
No specific pharmacokinetic-based dose adjustments; however, use lowest effective dose for shortest duration, especially after 20 weeks. Avoid use after 30 weeks gestation due to fetal risks. Increased volume of distribution may reduce serum concentrations but no dose adjustment recommended.
Phendimetrazine tartrate is a schedule III controlled substance with high abuse potential. It is approved only for short-term (up to 12 weeks) monotherapy for exogenous obesity. Contraindicated in patients with glaucoma, hyperthyroidism, agitated states, history of drug abuse, or cardiovascular disease. Taper dose to avoid withdrawal. Monitor blood pressure and heart rate; may cause pulmonary hypertension. Avoid use with MAOIs (risk of hypertensive crisis) and within 14 days of discontinuation.
ALEVE (naproxen sodium) is a nonsteroidal anti-inflammatory drug (NSAID) with a longer half-life (12-17 hours) allowing twice-daily dosing. It carries a boxed warning for cardiovascular and gastrointestinal risk. Use lowest effective dose for shortest duration. Contraindicated in patients with aspirin allergy, perioperative pain in CABG surgery, and significant renal impairment. Monitor renal function in elderly, volume-depleted patients, and those on ACE inhibitors or diuretics.
Take exactly as prescribed; do not increase dose or duration.,Take last dose of the day 4-6 hours before bedtime to prevent insomnia.,Do not crush or chew extended-release tablets; swallow whole.,Avoid driving or operating heavy machinery until you know how this medication affects you.,Report chest pain, shortness of breath, fainting, or leg swelling immediately.,Do not stop abruptly; follow your doctor's tapering plan.,Store securely; keep out of reach of others as this medication can be habit-forming.,Do not take with alcohol or other CNS stimulants.,Use with caution if you have high blood pressure, diabetes, or a history of depression.
Take with food or milk to reduce GI upset.,Do not exceed 2 tablets (440 mg) in 24 hours unless directed by a doctor.,Avoid alcohol consumption to lower risk of GI bleeding.,Stop use and seek medical help if you experience chest pain, weakness, slurred speech, or signs of stomach bleeding (black/tarry stools, vomit that looks like coffee grounds).,Do not use with other NSAIDs (e.g., ibuprofen, aspirin) unless prescribed.
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about PHENDIMETRAZINE TARTRATE vs ALEVE, answered by our medical review team.
PHENDIMETRAZINE TARTRATE is a Anorectic (Sympathomimetic) that works by Phendimetrazine is a sympathomimetic amine that acts as an appetite suppressant by stimulating the hypothalamus to release norepinephrine, leading to decreased food intake and increased energy expenditure. It is a prodrug that is metabolized to phenmetrazine, which is a potent central nervous system stimulant with amphetamine-like effects.. ALEVE is a Nonsteroidal Anti-inflammatory Drug (NSAID) that works by Naproxen, a nonsteroidal anti-inflammatory drug (NSAID), inhibits cyclooxygenase (COX-1 and COX-2) enzymes, thereby reducing prostaglandin synthesis. This leads to decreased inflammation, pain, and fever.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between PHENDIMETRAZINE TARTRATE and ALEVE depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of PHENDIMETRAZINE TARTRATE is: Oral: 35 mg twice daily or three times daily, 1 hour before meals; extended-release: 105 mg once daily in the morning.. The standard adult dose of ALEVE is: 220 mg orally every 8 to 12 hours as needed; maximum 660 mg per day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between PHENDIMETRAZINE TARTRATE and ALEVE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. PHENDIMETRAZINE TARTRATE is classified as Category C. First trimester: Limited data; potential for increased risk of oral clefts. Second/third trimester: Anorexiant effects may cause fetal growth restriction; avoid use due to maternal. ALEVE is classified as Category C. First trimester: Risk of spontaneous abortion and cardiac defects (odds ratio 1.86 for NSAIDs). Second trimester: Possible fetal renal dysfunction and oligohydramnios; ductus arter. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.