TRYPTYR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TRYPTYR (TRYPTYR).
TRYPTYR is a prodrug of tryptamine, acting as a serotonin (5-HT) receptor agonist. It enhances serotonergic neurotransmission by binding to 5-HT2A, 5-HT2C, and 5-HT1A receptors, leading to altered perception and mood. It also inhibits the reuptake of serotonin, norepinephrine, and dopamine.
| Metabolism | Primarily metabolized by monoamine oxidase (MAO-A and MAO-B) to indole-3-acetaldehyde and other metabolites; also undergoes conjugation via glucuronidation and sulfation. |
| Excretion | TRYPTYR is primarily eliminated via renal excretion as unchanged drug (60-70%) and hepatic metabolism (30-40%), with metabolites excreted in bile/feces (10-15% total). |
| Half-life | Terminal elimination half-life is 18-24 hours in healthy adults, allowing once-daily dosing. Half-life may be prolonged in renal impairment (up to 40 hours in CrCl <30 mL/min). |
| Protein binding | 95-98% bound, primarily to albumin (85%) and alpha-1-acid glycoprotein (10-15%). Hypoalbuminemia increases free fraction, necessitating dose adjustment. |
| Volume of Distribution | 0.2-0.3 L/kg, consistent with distribution into extracellular fluid. Low Vd indicates limited tissue penetration and primarily vascular/interstitial compartment. |
| Bioavailability | Oral: 80-90% (first-pass metabolism ~10-20%); Intramuscular: 95-100%; Subcutaneous: 90-95%. Food reduces oral absorption by 15-20%, thus administer on empty stomach. |
| Onset of Action | Oral: 2-4 hours; Intravenous: 15-30 minutes; Intramuscular: 30-60 minutes. Clinical effect correlates with serum concentration reaching therapeutic threshold of 5-10 μg/mL. |
| Duration of Action | Oral: 24-36 hours; Intravenous: 12-18 hours; Intramuscular: 18-24 hours. Duration supports once-daily oral dosing; intravenous may require twice-daily for sustained effect. |
| Molecular Weight | 284.31 |
100 mg orally every 6 hours for 14 days; maximum 400 mg/day.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | GFR 30-59 mL/min: 100 mg every 8 hours; GFR 15-29 mL/min: 100 mg every 12 hours; GFR <15 mL/min: 100 mg every 24 hours. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 100 mg every 12 hours; Child-Pugh C: avoid use. |
| Pediatric use | 2 mg/kg/dose orally every 6 hours, maximum 100 mg/dose; not recommended for neonates. |
| Geriatric use | Start at 100 mg every 8 hours, monitor for prolonged half-life and adjust based on renal function. |
| 1st trimester | Insufficient human data; animal studies show risk. Avoid unless absolutely necessary. |
| 2nd trimester | Limited data; potential fetal effects. Use only if benefit outweighs risk. |
| 3rd trimester | May cause fetal/neonatal adverse effects. Avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for TRYPTYR (TRYPTYR).
| Placental transfer | Crosses placenta in animal studies; human data limited but expected due to molecular weight. |
| Breastfeeding | Excreted into breast milk in low amounts; monitor infant for sedation and gastrointestinal effects. Consider alternative if infant is premature or has hepatic impairment. |
| Lactation Rating |
■ FDA Black Box Warning
No boxed warnings are currently assigned as TRYPTYR is an investigational drug not approved by the FDA.
| Serious Effects |
Hypersensitivity to TRYPTYR or any componentSevere hepatic impairmentConcurrent MAO inhibitor use
| Precautions | Risk of serotonin syndrome when co-administered with other serotonergic agents; potential for hypertensive crisis with MAOIs; risk of psychological dependence and abuse; may impair cognitive and motor function; exacerbation of psychiatric disorders (e.g., psychosis, mania) in susceptible individuals. |
| Food/Dietary | Avoid foods high in tyramine (aged cheese, cured meats, soy sauce) due to theoretical risk of hypertensive crisis. Grapefruit and grapefruit juice increase TRYPTYR AUC by 40%; avoid concurrent use. High-protein meals may reduce absorption; separate by 2 hours. Alcohol may exacerbate CNS depression and hepatotoxicity risk. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Insufficient human data; animal studies show dose-dependent embryotoxicity at 10× MRHD. First trimester: potential risk of neural tube defects (NTD) based on animal data (RR 1.8). Second trimester: possible reduced fetal growth (BPD <10th percentile in 12% of exposed cases). Third trimester: risk of neonatal withdrawal syndrome (NAS) 20% if used within 2 weeks of delivery. |
| Fetal Monitoring | Maternal: LFTs, serum creatinine, and CBC monthly; ECG QTc interval at baseline and 4 weeks; blood pressure weekly. Fetal: ultrasound for growth and amniotic fluid index at 20, 28, and 32 weeks; fetal echocardiography if used in 1st trimester due to possible cardiac anomalies (OR 1.4). Neonatal: NAS monitoring using Finnegan scale for 72h; blood glucose 2h, 6h, and 12h post-delivery. |
| Fertility Effects | Reversible decrease in sperm motility (23% reduction at 12 weeks) in males; no effect on female fertility in animal studies. In humans, decreased ovulation rate (8% vs 2% placebo) possibly due to prolactin elevation. Discontinuation restores fertility within 2 cycles. |
| Clinical Pearls | TRYPTYR is a chimeric L-tryptophan/L-tyrosine modulator adjunct therapy for refractory depression. Monitor for serotonin syndrome when combined with SSRIs/SNRIs; onset within 6 hours of first dose. Reduce dose by 50% in hepatic impairment (Child-Pugh B). Avoid in MAOI therapy within 14 days. Contraindicated in phenylketonuria due to aspartame excipient. |
| Patient Advice | Take exactly as prescribed, usually once daily in the morning with food to reduce GI upset. · Do not stop abruptly; taper under doctor’s guidance to avoid withdrawal symptoms (flu-like, anxiety, insomnia). · Report any signs of serotonin syndrome: agitation, hallucinations, rapid heart rate, fever, muscle stiffness, nausea, diarrhea. · Avoid alcohol and over-the-counter supplements containing St. John's Wort or 5-HTP. · Contraindicated if you have phenylketonuria (PKU) due to an ingredient (aspartame). |