TEPANIL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TEPANIL (TEPANIL).
TEPANIL (diethylpropion) is a sympathomimetic amine that acts as a norepinephrine reuptake inhibitor in the hypothalamus, increasing norepinephrine levels in the synaptic cleft, which stimulates beta-2 adrenergic receptors, leading to appetite suppression.
| Metabolism | Hepatic metabolism via CYP450 isoenzymes, primarily N-dealkylation and deamination. Active metabolites include N-ethyl- and N,N-diethyl- derivatives. |
| Excretion | Renal: 90% (as metabolites and unchanged drug), Fecal: <10% |
| Half-life | 4-6 hours; clinical context: requires multiple daily dosing for sustained anorectic effect |
| Protein binding | 30-40% bound to albumin |
| Volume of Distribution | 3-4 L/kg; indicates extensive tissue distribution |
| Bioavailability | Oral: 60-70% due to first-pass metabolism |
| Onset of Action | Oral: 30-60 minutes, Intravenous: immediate |
| Duration of Action | Oral: 4-6 hours; clinical notes: maximum effect at 1-2 hours post-dose, needs t.i.d. dosing |
| Molecular Weight | 240.34 |
25 mg orally three times daily, 1 hour before meals, or 75 mg extended-release orally once daily in the morning.
| Dosage form | TABLET |
| Renal impairment | Contraindicated in end-stage renal disease. For GFR <30 mL/min: not recommended. For GFR 30-59 mL/min: use with caution and monitor for adverse effects. |
| Liver impairment | Contraindicated in severe hepatic impairment. For Child-Pugh Class B: reduce dose by 50% or consider alternative. For Child-Pugh Class A: no adjustment required. |
| Pediatric use | Not recommended for use in children below 16 years of age due to lack of safety and efficacy data. |
| Geriatric use | Starting dose of 25 mg once daily in the morning, with slow titration upwards. Monitor for cardiovascular and psychiatric effects due to increased sensitivity. |
| 1st trimester | Data insufficient; animal studies show fetal harm. Use only if benefit outweighs risk. |
| 2nd trimester | Avoid due to risk of fetal tachycardia and potential for growth restriction. |
| 3rd trimester | Avoid due to risk of neonatal withdrawal, tachycardia, and increased irritability. |
Clinical note
Comprehensive clinical and safety monograph for TEPANIL (TEPANIL).
| Placental transfer | Crosses placenta; evidence from animal studies and clinical observations. Extent not well quantified. |
| Breastfeeding | Diethylpropion is excreted into breast milk in small amounts. Potential for infant stimulation, insomnia, and weight gain reduction. Use with caution or avoid, especially in preterm or ill infants. |
| Lactation Rating |
■ FDA Black Box Warning
None.
| Serious Effects |
Cardiovascular disease (e.g., coronary artery disease, arrhythmias, hypertension)History of drug abuseHyperthyroidismGlaucomaConcomitant use or within 14 days of MAOIsPregnancy (category X)Lactation
| Precautions | Pulmonary hypertension: Cases of primary pulmonary hypertension (PPH) have been reported; avoid in patients with known pulmonary hypertension., Valvular heart disease: Association with regurgitant cardiac valvular disease; avoid in patients with structural cardiac abnormalities., Serotonin syndrome: Risk when co-administered with serotonergic drugs or MAOIs; allow 14 days after MAOI discontinuation., CNS stimulation: May cause dizziness, insomnia, and euphoria; avoid with alcohol or other CNS stimulants., Tolerance/dependence: Tolerance develops with prolonged use; potential for psychological dependence; limit use to 8-12 weeks., Hypertension: Monitor blood pressure; exacerbate pre-existing hypertension. |
| Food/Dietary | Avoid caffeine, as it may increase stimulant effects and risk of palpitations. Avoid alcohol, which can potentiate CNS effects and increase seizure risk. Take with food if gastrointestinal upset occurs. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Pregnancy Category X. TEPANIL (diethylpropion) is contraindicated in pregnant women due to anorectic effects potentially causing fetal malnutrition and growth restriction. First trimester exposure may increase risk of neural tube defects, though human data limited. Second and third trimester exposure may lead to reduced birth weight and neonatal withdrawal symptoms including irritability and tremors. |
| Fetal Monitoring | Monitor maternal weight, blood pressure, and heart rate due to stimulant effects. Fetal growth assessment via ultrasound recommended. Observe for signs of neonatal withdrawal (irritability, hypertonia, tremors) in newborns if exposed near term. |
| Fertility Effects | May impair fertility in females by altering ovulatory function due to anorectic and central nervous system effects. No specific human data on male fertility; theoretical risk of reduced libido or erectile dysfunction. |
| Clinical Pearls | TEPANIL is a schedule IV controlled substance; assess for history of substance abuse before prescribing. Avoid use in patients with cardiovascular disease, hyperthyroidism, glaucoma, or agitated states. Monitor blood pressure and heart rate regularly. Use only for short-term (8-12 weeks) as tolerance develops. Do not combine with MAOIs or within 14 days of MAOI use. May cause insomnia; advise last dose before 6 PM. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency due to abuse potential. · May cause dizziness or blurred vision; avoid driving until you know how this medicine affects you. · Report chest pain, shortness of breath, or leg swelling immediately. · Avoid alcohol and caffeine-containing products while taking this medication. · Do not stop abruptly; taper under medical supervision to avoid withdrawal symptoms. · Tell your doctor if you have a history of drug abuse or mental health issues. |