Pimavanserin (Nuplazid) may improve psychiatric symptoms of Parkinson's disease while also causing adverse reactions.

I. Common Side Effects

1. Peripheral edema:

Incidence approximately 7% (2% in placebo group), manifested as swelling of hands, feet, or lower limbs.

2. Confusional state:

Incidence approximately 6% (3% in placebo group), possibly presenting as confusion, difficulty concentrating.

3. Other relatively common reactions:

(1) Nausea (7%), hallucinations (5%), constipation (4%), gait disturbance (2%).

(2) Some patients may discontinue due to urinary tract infection or fatigue.

II. Serious Side Effects Requiring Vigilance

1. QT interval prolongation:

(1) This drug can cause prolongation of the QT interval on ECG, increasing the risk of arrhythmias.

(2) Mean prolongation of approximately 5-8 milliseconds during treatment, more pronounced at higher doses.

2. Allergic reactions:

Post-marketing reports indicate possible rash, urticaria, angioedema (tongue swelling, throat tightness, dyspnea).

3. Other serious reactions:

Falls, somnolence, agitation, aggressive behavior, fecal incontinence have also been reported.

III. Methods to Alleviate Side Effects

1. Managing edema:

(1) Elevate lower limbs for rest, avoid prolonged sitting or standing, engage in appropriate physical activity to promote blood circulation.

(2) If edema is significant or accompanied by difficulty breathing, seek medical attention promptly.

2. Managing nausea and constipation:

(1) For nausea, try drinking small amounts of water frequently, avoid taking medication on an empty stomach.

(2) For constipation, increase dietary fiber intake (e.g., vegetables, fruits), ensure adequate hydration, use mild laxatives under physician guidance.

3. Preventing falls:

Gait may be affected during treatment; consider using a walking aid, keep floors dry and pathways unobstructed at home, use night lights.

4. Monitoring mental status:

If confusion or worsening hallucinations occur, caregivers should observe closely and inform the physician promptly, do not adjust dosage on your own.

5. Cardiac precautions:

(1) An ECG should be performed before treatment, avoid concomitant use of other QT-prolonging drugs (e.g., certain antibiotics, antiarrhythmics) during therapy.

(2) If palpitations or syncope occur, seek immediate medical attention.

IV. Drug Storage Conditions

1. Capsules:

(1) Store at 20–25°C room temperature, brief excursions permitted between 15–30°C.

(2) Protect from light to prevent fading of capsule color.

2. General storage principles:

(1) Keep container tightly closed, away from moisture and high heat, do not store in bathroom or kitchen.

(2) Keep out of reach of children.

3. Drug interaction warning:

(1) When co-administered with strong CYP3A4 inhibitors (e.g., ketoconazole), reduce dose to 10 mg/day; avoid concomitant use with strong or moderate CYP3A4 inducers.

(2) Any dosage adjustments must be done under physician guidance.