Quetiapine fumarate 100 mg is a tablet form of quetiapine, an atypical antipsychotic. It’s used to treat certain mental health conditions and comes in immediate-release (IR) and extended-release (XR) formulations. The 100 mg strength is a common dose, but the exact amount of active drug and how it’s used depends on the formulation and the condition being treated.
What it’s used for (typical indications)
- Schizophrenia (IR or XR)
- Bipolar disorder:
- Mania or mixed episodes
- Bipolar depression
- Major depressive disorder (MDD) as an add-on (augmentation) to antidepressants (usually XR)
- Insomnia (low-dose off-label use; not a primary approved use)
General dosing concept (illustrative; your exact dose must come from your clinician)
- Schizophrenia:
- IR: start low (e.g., 25 mg twice daily) and gradually increase; target often in the 300–400 mg/day range, but higher doses are used in some cases.
- XR: start around 300 mg once daily at night and titrate as directed.
- Bipolar mania/mixed episodes:
- IR or XR, commonly in the 300–800 mg/day range (HD titration depending on response and tolerability).
- Bipolar depression:
- XR typically 300 mg once daily (adjust as guided).
- Major depressive disorder (augmentation):
- XR often 150–300 mg once daily.
- For insomnia (off-label, not usually first choice):
- Low doses such as 25–50 mg at bedtime.
Important safety and side effects
- Common: drowsiness/sedation, dizziness, dry mouth, weight gain, and increased appetite.
- Metabolic changes: weight gain, increased blood sugar, and cholesterol risk (monitor as advised).
- Extrapyramidal symptoms (EPS) and tardive dyskinesia can occur, especially at higher doses.
- Orthostatic hypotension (dizziness on standing).
- QT prolongation (rare; important for people with heart conditions or on other QT-prolonging meds).
- Elderly patients with dementia-related psychosis have an increased risk of death; use with caution.
- Can interact with alcohol and other central nervous system depressants (increases sedation).
Key interactions
- Strong CYP3A4 inhibitors or inducers can raise or lower quetiapine levels (e.g., ketoconazole increases levels; rifampin decreases them).
- Sedatives or alcohol can enhance drowsiness.
- Caution with other medications that can affect heart rhythm or blood pressure.
Administration tips
- XR tablets should be swallowed whole; do not crush or chew.
- IR tablets can be taken with or without food (consistent with how you start).
- Don’t stop suddenly without talking to your clinician; taper if changing or stopping.
Important note
- This is general information and not a substitute for medical advice. Your exact dose and whether quetiapine is right for you depend on your diagnosis, other medications, and health conditions. If you have a prescription, follow your doctor's instructions and discuss any questions or side effects with them.
If you’d like, tell me your condition (e.g., schizophrenia, bipolar disorder, MDD, or insomnia), and whether you’re asking about starting, changing dose, or safety with a specific other medication. I can tailor the information to your situation.