Precautions for Daily Use of Quizartinib

Quizartinib is a prescription drug; the dosage and course of treatment are determined by a hematologist. Do not adjust the dosage or stop the medication on your own. During the treatment period, please undergo regular monitoring of your ECG, blood potassium and magnesium levels, blood cell counts, and liver function as advised by your doctor.

Medication Precautions

1. Fixed schedule: Take the medication at approximately the same time every day. Swallow the tablet whole; do not cut, crush, or chew it.

2. Meals: It can be taken with or without food. A high-fat meal does not affect its absorption, so there is no need to adjust your meal times for it.

3. Missed dose: Take the missed dose as soon as possible on the same day, and resume your regular schedule the next day. Do not take two doses on the same day.

4. Vomiting: If vomiting occurs after taking the medication, do not take an extra dose; wait until the next scheduled dosing time.

5. Dosage adjustments for other medications: Before starting any new medication (including cold medicine, stomach medicine, traditional Chinese medicine, or dietary supplements), consult your doctor or pharmacist first.

Note: St. John's Wort is a strong CYP3A inducer, and its concurrent use should be avoided.

Regular Examinations

1. ECG: Once before dosing in the induction and consolidation phases, and once a week during treatment thereafter; once before dosing in the maintenance phase, once a week for at least the first month after initiation and dose escalation, and thereafter as clinically indicated.

2. Blood potassium and magnesium: Monitor and correct these levels before and during treatment to maintain them within the normal range.

3. During diarrhea or vomiting: Both of these conditions deplete potassium and magnesium, which directly increases the risk of QT prolongation. Therefore, electrolytes and ECGs must be checked more frequently during those days; do not wait for the next scheduled follow-up visit.

4. ECG monitoring should also be intensified when concurrently taking drugs known to prolong the QT interval.

Side Effects to Watch Out For

1. Seek Medical Attention Immediately

Symptoms related to QT prolongation: Dizziness, blackout/fainting, syncope, or palpitations. If any of these occur, seek medical attention immediately.

2. Consult a Doctor Promptly

Fever, especially when accompanied by chills or fever during neutropenia.

Bleeding tendency: Nosebleeds, bleeding gums, or increased skin bruising (ecchymosis).

Persistent diarrhea or vomiting, especially when accompanied by dry mouth, decreased urination, or fatigue—these are signs of an electrolyte imbalance.

Ask Your Doctor Before Use

1. Common drugs that prolong the QT interval, such as: azole antifungals, ondansetron, granisetron, azithromycin, pentamidine, doxycycline, moxifloxacin, atovaquone, prochlorperazine, and tacrolimus.

2. Strong CYP3A inhibitors: Co-administration requires a dose reduction according to specific guidelines.

3. Strong or moderate CYP3A inducers: Avoid co-administration, as they will reduce the drug's efficacy.