Indications
- Donepezil is utilized to treat confusion (dementia) associated with Alzheimer’s disease.
- While it doesn’t cure Alzheimer’s disease, it may enhance memory, awareness, and the ability to function.
- This medication functions as an enzyme blocker, working to restore the balance of natural substances (neurotransmitters) in the brain.
Dosage and administration
- Before starting donepezil, read the Patient Information Leaflet from your pharmacist. Consult your doctor or pharmacist if you have any questions.
- Take this medication orally, with or without food, as directed by your doctor, usually once daily just before bedtime. If sleep problems occur, discuss with your doctor the possibility of switching to a morning dose.
- If you are using 23-milligram strength tablets, swallow them whole. Do not split, crush, or chew these tablets, as it may increase the risk of side effects.
- Dosage is determined based on your medical condition and treatment response. To minimize side effects (like nausea and diarrhea), your doctor will initiate the medication at a low dose, gradually increasing it over weeks to months. Follow your doctor’s instructions carefully, and do not self-adjust the dose or use the drug more frequently than prescribed.
- If you miss taking donepezil for 7 or more consecutive days, consult your doctor before restarting. You may need to begin at a lower dose to reduce the risk of side effects.
- Use the medication regularly for maximum benefit. Take it at the same time each day to help remember. Do not discontinue it unless instructed by your doctor, and it may take several weeks to experience the full benefits.
- Inform your doctor if your condition worsens.
Side effects
- Common side effects of donepezil during the initial adjustment period may include nausea, vomiting, diarrhea, loss of appetite/weight loss, dizziness, drowsiness, weakness, trouble sleeping, shakiness (tremor), or muscle cramps. These effects typically last 1-3 weeks and then diminish. If persistent or worsening, inform your doctor or pharmacist promptly.
- This medication is prescribed because your doctor believes that its benefits outweigh the potential side effects. Many individuals using this medication do not experience serious side effects.
- Notify your doctor immediately if you observe serious side effects, such as trouble urinating, severe stomach/abdominal pain, black stools, vomit resembling coffee grounds, or seizures.
- Seek immediate medical help for very serious side effects, including slow/fast/irregular heartbeat, severe dizziness, or fainting.
- While a serious allergic reaction to this drug is rare, seek immediate medical help if you notice symptoms like rash, itching/swelling (especially face/tongue/throat), severe dizziness, or trouble breathing.
- The provided list is not exhaustive; contact your doctor or pharmacist for any unlisted effects.
Precautions
- Inform your doctor or pharmacist about any allergies to donepezil or other substances, as inactive ingredients may cause allergic reactions or other problems.
- Share your medical history with your doctor or pharmacist, especially breathing problems (such as asthma, chronic obstructive pulmonary disease), fainting, seizures, stomach/intestinal disease (ulcers, bleeding), and trouble urinating (such as enlarged prostate).
- Donepezil may induce dizziness or drowsiness. Alcohol or marijuana (cannabis) can exacerbate these effects. Avoid activities requiring alertness until safe to do so. Limit alcohol intake and discuss marijuana usage with your doctor.
- This medication may cause a condition affecting heart rhythm (QT prolongation), which can rarely lead to serious or fatal fast/irregular heartbeat and other symptoms requiring immediate medical attention (severe dizziness, fainting). The risk may increase with certain medical conditions or other drugs causing QT prolongation. Inform your doctor of all drugs taken and any relevant medical conditions.
- Low levels of potassium or magnesium in the blood may also elevate the risk of QT prolongation. Discuss the use of donepezil safely with your doctor, especially if using certain drugs (such as diuretics/”water pills”) or experiencing conditions like severe sweating, diarrhea, or vomiting.
- Before surgery, inform your doctor or dentist about all products you use, including prescriptions, non-prescriptions, and herbal items.
- Older adults may be more sensitive to the side effects of this drug, particularly QT prolongation.
- During pregnancy, use this medication only when clearly needed. Discuss the risks and benefits with your doctor.
- It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.