Comparative Pharmacology
Head-to-head clinical analysis: ADIPEX P versus OBY TRIM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ADIPEX P versus OBY TRIM.
ADIPEX-P vs OBY-TRIM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Phentermine is a sympathomimetic amine that stimulates release of norepinephrine and to a lesser extent dopamine and serotonin from presynaptic nerve terminals in the hypothalamic feeding center, resulting in appetite suppression.
OBY-TRIM is a combination of phentermine, a sympathomimetic amine anorectic that stimulates the hypothalamus to release norepinephrine, suppressing appetite, and a diuretic (often a thiazide) to reduce fluid retention.
Phentermine (ADIPEX-P) is typically dosed as 15–37.5 mg orally once daily, administered 2 hours after breakfast or before breakfast. The 37.5 mg tablet is taken once daily before breakfast or 1–2 hours after breakfast; some patients may require 15 mg or 30 mg (half of a 37.5 mg tablet) once daily. The extended-release formulation (ADIPEX-P) is not available; only immediate-release tablets are marketed. Duration of therapy should be limited to a few weeks (e.g., 4–12 weeks) due to potential for tolerance and abuse.
Oral: 1 capsule (phentermine 18.75 mg / chlorpheniramine 6.25 mg) twice daily, 30 minutes before meals.
None Documented
None Documented
Terminal half-life approximately 20-25 hours. Clinical context: Steady-state reached within 4-5 days; dosing adjustments may be needed in renal impairment.
Terminal half-life is approximately 20–30 hours in adults with normal renal function. This allows for once-daily dosing in most patients.
Primarily renal (70-90% unchanged); minor biliary/fecal (10-30% as metabolites). Urinary pH-dependent; acidic urine increases excretion.
Primarily renal (90% as unchanged drug and metabolites), with about 10% biliary/fecal. In an acidic urine, elimination half-life increases.
Category C
Category C
Anorexiant
Anorexiant