Simtriyo

　　I.Basic Information

　　Drug Name:Simtriyo(generic name:centanafadine)

　　Developer and Manufacturer:Otsuka Pharmaceutical Co.,Ltd

　　II.Indications

　　Simtriyo(centanafadine)is indicated for the treatment of attention-deficit/hyperactivity disorder(ADHD)in adult and pediatric patients aged 6 years and older with a body weight of at least 20 kg.

　　Limitations of Use:

　　SIMTRIYO is not recommended for routine use in pediatric patients;

　　In children younger than 6 years,the incidence of weight loss is notably higher than in pediatric patients aged 6 years and above;

　　Insufficient clinical data exist for patients weighing less than 20 kg,and there is a potential risk of further weight reduction in this subgroup.

　　III.Dosage and Administration

　　1.Pre-Treatment Assessment and Ongoing Monitoring

　　A comprehensive baseline evaluation must be completed prior to initiating therapy,with continuous monitoring maintained throughout the treatment course.First,assess the patient's history for any predisposition to substance abuse or dependence;obtain a detailed family history of cardiac events,including sudden cardiac death and ventricular arrhythmias,and document baseline heart rate and blood pressure readings.Second,screen for psychiatric risk factors by inquiring about personal or family history of depression,bipolar disorder,or suicidal ideation.Third,in patients with a family history of tics or movement disorders,perform a targeted physical examination to identify any vocal or motor tic manifestations and prevent potential exacerbation upon drug exposure.Additionally,patients who have previously received monoamine oxidase inhibitors(MAOIs)must observe a minimum washout period of 14 days before commencing treatment with this product.

　　2.Recommended Dosing by Age Group

　　(1)Children aged 6 to 12 years with body weight≥20 kg:For patients weighing 20 kg to less than 35 kg,the recommended dose is 140 mg once daily;

　　(2)For patients weighing 35 kg to 50 kg,the recommended dose is 210 mg once daily;

　　(3)For patients exceeding 50 kg,the recommended dose is 280 mg once daily.

　　Note:The efficacy of the 140 mg and 210 mg strengths has not been fully established;these doses serve solely as the standard prescribed amount for their respective weight brackets.

　　(4)Adolescents aged 13 to 17 years(body weight≥20 kg):A fixed dose of 280 mg once daily is recommended.Lower-dose regimens lack supporting efficacy data and are not advised.

　　(5)Adult patients:An initial dose of 210 mg once daily is recommended,with the option to titrate upward to a maximum of 280 mg once daily based on clinical response and tolerability.

　　3.Administration Instructions and Missed Dose Management

　　This product is an extended-release formulation.The capsule and its internal granules must not be split,crushed,or chewed.Administration is recommended at a consistent time each morning,with or without food.Two methods of administration are available:first,swallow the capsule whole with water;second,open the capsule and sprinkle all granules evenly onto one tablespoon of applesauce,yogurt,or orange juice,consume immediately followed by adequate water intake—granules must not be chewed,and the mixture must be consumed promptly without storage.In the event of a missed dose,a supplemental dose may be taken only within 4 hours of the scheduled time,with a maximum of one dose per day;if more than 4 hours have elapsed,the missed dose should be skipped and the regular schedule resumed the following day.

　　IV.Adverse Reactions

　　Based on pooled clinical trial data across age groups,the common adverse reactions associated with Simtriyo vary by patient age:

　　Pediatric patients aged 6 to 12 years:rash,decreased appetite;

　　Adolescent patients aged 13 to 17 years:decreased appetite,nausea,rash,headache,abdominal pain;

　　Adult patients:headache,decreased appetite,insomnia,nausea,dry mouth,diarrhea,somnolence.

　　V.Supply and Storage

　　Simtriyo extended-release capsules are available in three strength specifications:140 mg,210 mg,and 280 mg.Store at controlled room temperature between 20°C and 25°C(68°F to 77°F);excursions permitted between 15°C and 30°C(59°F to 86°F).

　　VI.Contraindications

　　Simtriyo is contraindicated in the following circumstances:

　　Patients with known hypersensitivity to centanafadine or any excipient contained in Simtriyo.Post-marketing reports have documented allergic reactions including angioedema and anaphylaxis.

　　Patients currently receiving monoamine oxidase inhibitors(MAOIs)or who have discontinued MAOIs within the preceding 14 days.Concurrent use may precipitate serious and potentially fatal drug interactions,including hypertensive crisis and serotonin syndrome.

　　Patients with a confirmed diagnosis of pheochromocytoma or a history of pheochromocytoma.Severe adverse events,including acute hypertensive episodes and tachyarrhythmias,have been reported in such patients treated with central nervous system stimulants.

　　VII.Mechanism of Action

　　Centanafadine exhibits inhibitory activity against the reuptake transporters for norepinephrine(NE),dopamine(DA),and serotonin(5-HT),and is pharmacologically classified as a central nervous system stimulant.The precise mechanism by which centanafadine exerts its therapeutic effect in ADHD has not been fully elucidated;however,its efficacy is believed to be mediated through its activity as a norepinephrine-dopamine-serotonin reuptake inhibitor(NDSRI),producing synergistic blockade across all three monoaminergic pathways.