BIPHETAMINE 12.5
Clinical safety rating
cautionComprehensive clinical and safety monograph for BIPHETAMINE 12.5 (BIPHETAMINE 12.5).
Biphetamine 12.5 is a central nervous system stimulant that increases the levels of norepinephrine and dopamine in the synaptic cleft by inhibiting the reuptake of these neurotransmitters and by promoting their release from presynaptic terminals.
| Metabolism | Hepatic metabolism via CYP2D6 and other pathways; primarily deamination and oxidation. |
| Excretion | Renal: 70-80% as unchanged drug and metabolites (primarily deaminated metabolites); fecaroute is negligible. Urinary pH-dependent: acidification increases renal clearance, alkalinization decreases it. |
| Half-life | 9-14 hours in children and adolescents; clinical effects typically last 4-6 hours due to distribution and tolerance. Terminal half-life may be longer in adults with higher body fat (up to 20 hours). |
| Protein binding | 20-40%, primarily to albumin and alpha-1 acid glycoprotein. |
| Volume of Distribution | 3.2-5.6 L/kg, indicating extensive tissue distribution; crosses blood-brain barrier readily. |
| Bioavailability | Oral: 75-100% (amphetamines have high and consistent oral bioavailability). |
| Onset of Action | Oral: 30-60 minutes; central nervous system effects peak at 2-3 hours. |
| Duration of Action | Oral: Behavioral effects last 4-6 hours; use in ADHD often requires multiple daily doses or extended-release formulations. |
| Molecular Weight | 135.21 |
12.5 mg orally once daily in the morning, may titrate weekly by 12.5 mg to maximum 75 mg/day.
| Dosage form | CAPSULE, EXTENDED RELEASE |
| Renal impairment | GFR <30 mL/min: avoid use; GFR 30-60 mL/min: reduce dose by 50% and monitor; GFR >60 mL/min: no adjustment. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: avoid use. |
| Pediatric use | 6-12 years: 6.25 mg or 12.5 mg once daily in the morning, may increase by 6.25 mg weekly up to 37.5 mg/day; weight-based: 0.3-0.8 mg/kg/day, max 37.5 mg/day. |
| Geriatric use | Initiate at 6.25 mg once daily in the morning, increase cautiously by 6.25 mg weekly; monitor for cardiovascular and psychiatric effects; maximum daily dose 37.5 mg. |
| 1st trimester | Associated with increased risk of congenital malformations, particularly cardiovascular defects and oral clefts; avoid use unless benefit clearly outweighs risk. |
| 2nd trimester | May cause fetal growth restriction and maternal hypertension; use only if clearly needed. |
| 3rd trimester | Can lead to premature delivery, low birth weight, and neonatal withdrawal symptoms; avoid use in late pregnancy. |
Clinical note
Comprehensive clinical and safety monograph for BIPHETAMINE 12.5 (BIPHETAMINE 12.5).
| Placental transfer | Amphetamines cross the placenta; studies in animals show teratogenicity and embryotoxicity. |
| Breastfeeding | Amphetamines are excreted into breast milk; concentrations are higher than maternal plasma. Use in nursing mothers may cause irritability, poor feeding, and insomnia in infants; breast-feeding is generally not recommended during therapy. |
| Lactation Rating | L5 - Avoid (Contraindicated) |
| Teratogenic Risk | First trimester: Possible increased risk of congenital malformations (e.g., heart defects, oral clefts) based on limited human data; animal studies show fetal abnormalities. Second and third trimesters: Risk of prematurity, low birth weight, and neonatal withdrawal symptoms (e.g., irritability, poor feeding). Amphetamines may cause vasoconstriction leading to placental insufficiency. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, weight gain, and signs of abuse/dependence. Fetal monitoring with ultrasound for growth restriction and placental function. Neonatal monitoring for withdrawal symptoms and growth parameters after delivery. |
| Fertility Effects | May reduce fertility in females through disruption of hormonal cycles (e.g., anovulation). In males, may impair spermatogenesis and libido. Effects are likely reversible upon discontinuation. |
■ FDA Black Box Warning
Biphetamine has a high potential for abuse and dependence. Prolonged use may lead to drug dependence. Misuse may cause sudden death or serious cardiovascular events.
| Serious Effects |
Advanced arteriosclerosisSymptomatic cardiovascular diseaseModerate to severe hypertensionHyperthyroidismKnown hypersensitivity to amphetaminesGlaucomaAgitated statesHistory of drug abuseDuring or within 14 days of MAO inhibitor use (hypertensive crisis risk)
| Precautions | Risk of serious cardiovascular events including sudden death in patients with pre-existing structural cardiac abnormalities or other serious heart problems, Risk of hypertension and tachycardia, Risk of psychiatric adverse events such as exacerbation of pre-existing psychosis, mania, or aggression, Risk of seizures in patients with a history of seizures, Long-term suppression of growth in children |
| Food/Dietary | Avoid high-fat meals as they may delay absorption. Limit caffeine intake (coffee, tea, colas) as it may increase stimulant effects and risk of side effects. Acidic foods/juices (e.g., orange juice, grapefruit juice) can decrease absorption; take medication with water. Maintain adequate hydration. |
| Clinical Pearls | Biphetamine 12.5 is a mixed amphetamine salt product (D-amphetamine and L-amphetamine). Monitor for cardiovascular events, especially in patients with pre-existing conditions. Avoid use within 14 days of MAOIs. Use with caution in patients with hypertension, hyperthyroidism, glaucoma, or history of drug abuse. Assess for tics or Tourette's syndrome. Monitor growth in pediatric patients. May cause withdrawal symptoms upon abrupt discontinuation. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency without consulting your doctor. · Avoid taking late in the day to prevent insomnia. · Report any chest pain, shortness of breath, or fainting immediately. · May cause dizziness or blurred vision; avoid driving until you know how the medication affects you. · Do not stop abruptly; your doctor will taper the dose to avoid withdrawal symptoms. · Inform your doctor if you have a history of heart problems, high blood pressure, seizures, or mental health conditions. · Avoid alcohol and other CNS stimulants. · Store at room temperature away from moisture and heat. |
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