Guanfaxin sustained-release tablets (Intuniv) are mainly used as alpha 2A adrenergic receptor agonists for the treatment of ADHD, and their side effects mainly involve the cardiovascular system, central nervous system, and digestive system. Most adverse reactions are dose-dependent and can be alleviated by adjusting the dosing regimen or symptomatic treatment.

1. Cardiovascular system response

(1) Blood pressure drop: At the beginning of treatment, the average systolic blood pressure drops by 5-10mmHg. It is recommended to take medication in the morning to avoid rapid changes in body position.

(2) Bradycardia: heart rate may decrease by 4-8 beats per minute. Baseline electrocardiogram should be performed before medication to avoid combination with beta blockers.

2. Central nervous system impact

(1) Sleepiness and fatigue: The incidence rate is about 40%. It is recommended to take medication before bedtime, and the symptoms should be relieved on their own after 2-4 weeks.

(2) Headache and dizziness: Maintain sufficient water intake and use acetaminophen for short-term relief if necessary.

3. Digestive system symptoms

(1) Abdominal pain and nausea: incidence rate of 15-20%. It is recommended to take it with food and administer it in divided doses to alleviate symptoms.

(2) Decreased appetite: Monitor weight changes and recommend high calorie nutritional supplements for pediatric patients.

4. Special precautions

(1) Withdrawal reaction: Sudden discontinuation of medication can cause rebound hypertension, requiring a 25% dose reduction every 3-7 days.

(2) Abnormal liver function: The incidence of elevated ALT is about 2%, and liver function should be monitored before medication and every 6 months.

(3) Drug interactions: Strong CYP3A4 inhibitors (such as ketoconazole) can double blood drug concentrations, requiring a 50% reduction.

5. Dose adjustment strategy

(1) Children (6-12 years old): Starting at 1mg/day, increasing by 1mg per week to a target dose of 1-4mg/day.

(2) Adults (≥ 13 years old): Start at 1mg/day, maximum dose not exceeding 7mg/day, and reduce dosage for those with renal insufficiency.