Phentermine 37.5mg | Topiramate 25mg

Route: Oral capsule.

• Take once daily in the morning, with or without food.
• Avoid evening dosing—phentermine's stimulant properties may cause insomnia if taken late in the day.
• Swallow the capsule whole with a full glass of water. Do not split, crush, or open.
• Take at the same time each day for consistent plasma levels.

Prescriber-determined. The compounded 37.5 mg / 25 mg dose is a higher-phentermine, lower-topiramate combination compared to the FDA-approved Qsymia maximum dose (15 mg / 92 mg); clinical context and individual patient tolerability guide dosing. General considerations:

• In the FDA-approved Qsymia titration scheme, therapy is initiated at lower doses (phentermine 3.75 mg / topiramate 23 mg) with gradual escalation; prescribers should consider a similar approach when using compounded formulations.
• Assess weight loss response at 12 weeks; a minimum 3% reduction in body weight is typically expected for continued benefit.
• Topiramate should be tapered rather than abruptly stopped to minimize seizure risk.
• All dosing is determined by the prescribing clinician based on individual risk-benefit assessment.

• Phentermine: Acts on TAAR1 to induce presynaptic norepinephrine (and lesser dopamine) release in the hypothalamic lateral hypothalamic area. This adrenergic surge suppresses appetite by decreasing orexigenic neuropeptide signals (NPY, AgRP) and increasing sympathetic-mediated thermogenesis.
• Topiramate: Potentiates inhibitory GABA-A receptor chloride currents; antagonizes excitatory AMPA/kainate glutamate receptors; inhibits carbonic anhydrase (isoforms CA-II and CA-IV). The combined effect is neuronal stabilization and blunting of the reward-related motivational drive to eat. Topiramate's exact mechanism for appetite suppression is not fully elucidated but likely involves effects on reward and satiety signaling in mesolimbic circuits.

Indication context: Indicated for adults with a BMI ≥30 kg/m² or ≥27 kg/m² with at least one weight-related comorbidity (type 2 diabetes, hypertension, dyslipidemia), as part of a comprehensive weight management program. The phentermine-topiramate combination is supported by two pivotal 56-week randomized controlled trials showing average weight losses of 7–11% at maximum doses, along with improvements in cardiometabolic risk factors.

Monitoring considerations:

• Blood pressure and heart rate monitoring (phentermine raises BP/HR in some patients).
• Serum bicarbonate monitoring for metabolic acidosis (topiramate's carbonic anhydrase inhibition).
• Body weight and BMI at each visit; evaluate response at 12 weeks.
• Monthly pregnancy tests for women of childbearing potential; ensure effective contraception.
• Ophthalmologic assessment if acute vision changes or ocular pain occur (topiramate-associated secondary angle-closure glaucoma).
• Monitor for cognitive side effects (word-finding difficulty, memory impairment) at each visit.

Contraindications:

• Pregnancy (teratogenicity—cleft palate risk with topiramate; Pregnancy Category X for phentermine).
• Concurrent or within 14 days of MAOI use.
• Uncontrolled hypertension, hyperthyroidism, glaucoma.
• Known hypersensitivity to phentermine, topiramate, or formulation excipients.

Warnings & Precautions:

• Acute secondary angle-closure glaucoma: Topiramate can induce acute myopia with secondary angle-closure glaucoma within weeks of initiation; discontinue immediately and seek ophthalmologic care if acute visual changes or pain occur.
• Cardiovascular: Phentermine increases resting heart rate; dose-dependent increase in HR observed in trials; long-term cardiovascular safety in patients with known cardiac disease is not established.
• Oligohydrosis (decreased sweating) and hyperthermia with topiramate; caution in warm environments.
• Nephrolithiasis: Topiramate increases kidney stone risk; maintain high fluid intake; avoid ketogenic diets concurrently.
• Cognitive impairment and word-finding difficulty: dose-related with topiramate; may require dose reduction.
• Metabolic acidosis: monitor serum bicarbonate periodically; assess for Kussmaul respirations.

Drug Interactions:

• MAOIs: contraindicated with phentermine.
• Oral contraceptives: topiramate may reduce efficacy; advise alternative contraception.
• Antihypertensives: phentermine may oppose antihypertensive effect.
• Valproic acid + topiramate: risk of hyperammonemia and encephalopathy.
• CNS depressants and alcohol: enhanced CNS depression with topiramate.

Common Side Effects: Paresthesias (tingling in hands/feet), dizziness, dysgeusia (altered taste), insomnia, constipation, dry mouth; less commonly—increased heart rate, irritability.

Store at room temperature (15–30°C / 59–86°F). Protect from moisture and heat. Keep tightly capped in the original dispensing container. Phentermine is a federally controlled substance (Schedule IV); store securely. Do not freeze. Use within the beyond-use date assigned by Genesis Compounding per USP <795> guidelines.

How does this combination differ from taking phentermine alone?

Phentermine alone suppresses appetite through norepinephrine release but has relatively short-term efficacy and carries stimulant effects. Topiramate adds a complementary mechanism—enhancing satiety and reducing reward-driven eating—while also permitting use of lower individual doses, potentially improving tolerability and extending duration of effect.

Why must I take this in the morning?

Phentermine has stimulant properties that can cause insomnia if taken later in the day. Morning dosing maximizes appetite suppression during waking hours and minimizes sleep disruption.

What should I do if I develop eye pain or blurred vision?

Contact your prescriber or seek ophthalmologic care immediately. Topiramate can rarely cause acute secondary angle-closure glaucoma—an ocular emergency—within weeks of initiation. Do not wait for a scheduled appointment if acute visual symptoms occur.

Does topiramate require tapering when stopping?

Yes. Abrupt discontinuation of topiramate is associated with seizure risk. Your prescriber will provide a tapering schedule when it is time to discontinue this medication.

Is this the same as Qsymia?

This compounded capsule contains the same two active ingredients as Qsymia (phentermine and topiramate) but at a different dose ratio. Qsymia is an FDA-approved extended-release capsule. This is a patient-specific 503A compounded preparation prepared by Genesis Compounding and is not FDA-approved as a compounded product.