Donepezil 5mg Tablets
It is used to treat dementia in people with Alzheimer's disease.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Cholinesterase Inhibitor
Pharmacologic Class
Acetylcholinesterase Inhibitor
Pregnancy Category
Category C
FDA Approved
Nov 1996
DEA Schedule
Not Controlled
Overview
What is this medicine?
Donepezil is a medication used to treat Alzheimer's disease. It works by increasing a natural substance in the brain called acetylcholine, which is important for memory, thinking, and reasoning. It can help improve or stabilize these abilities in some people with Alzheimer's.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Continue taking the medication as directed by your doctor or healthcare provider, even if you feel well. Take the medication at bedtime, with or without food. It is recommended to drink plenty of non-caffeinated liquids, unless your doctor advises you to limit your fluid intake.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, skip it and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you miss seven consecutive days of medication, contact your doctor for guidance on how to proceed.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Continue taking the medication as directed by your doctor or healthcare provider, even if you feel well. Take the medication at bedtime, with or without food. It is recommended to drink plenty of non-caffeinated liquids, unless your doctor advises you to limit your fluid intake.
Storing and Disposing of Your Medication
Store the medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs in your area.
Missing a Dose
If you miss a dose, skip it and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you miss seven consecutive days of medication, contact your doctor for guidance on how to proceed.
Lifestyle & Tips
- Take donepezil exactly as prescribed, usually once daily at bedtime.
- Do not stop taking donepezil suddenly without consulting your doctor, as this can worsen symptoms.
- Be aware of potential side effects like nausea, vomiting, diarrhea, dizziness, and insomnia, especially when starting or increasing the dose.
- Report any fainting spells, severe dizziness, or unusual heartbeats to your doctor immediately.
- Maintain regular follow-up appointments with your doctor to monitor your condition and medication effectiveness.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
5 mg orally once daily at bedtime for at least 4-6 weeks, then may increase to 10 mg orally once daily at bedtime.
Dose Range:
5 - 10 mg
Condition-Specific Dosing:
mild_to_moderate_alzheimers:
5 mg orally once daily at bedtime, titrate to 10 mg after 4-6 weeks.
moderate_to_severe_alzheimers:
10 mg orally once daily at bedtime, may consider 23 mg orally once daily after 3 months on 10 mg (for specific formulations).
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No dose adjustment necessary.
Moderate:
No dose adjustment necessary.
Severe:
No specific dose adjustment recommended, but use with caution and monitor for adverse effects.
Dialysis:
Donepezil is not dialyzable. No specific dose adjustment recommended, but use with caution.
Hepatic Impairment:
Mild:
No dose adjustment necessary.
Moderate:
Use with caution; consider slower titration or lower maintenance dose (e.g., 5 mg/day) if adverse effects occur.
Severe:
Use with extreme caution; not well studied. Consider lower starting dose and slower titration, or avoid if possible.
Pharmacology
Mechanism of Action
Donepezil is a reversible inhibitor of acetylcholinesterase, the enzyme responsible for the hydrolysis of acetylcholine. By inhibiting acetylcholinesterase, donepezil increases the concentration of acetylcholine in the synaptic cleft in the central nervous system, thereby enhancing cholinergic neurotransmission. This effect is thought to be beneficial in Alzheimer's disease, where there is a deficiency of cholinergic neurons.
Pharmacokinetics
Absorption:
Bioavailability:
100%
Tmax:
3-4 hours
FoodEffect:
Food does not affect the rate or extent of absorption.
Distribution:
Vd:
12 L/kg
ProteinBinding:
Approximately 96% (primarily to albumin and alpha1-acid glycoprotein)
CnssPenetration:
Yes, readily crosses the blood-brain barrier.
Elimination:
HalfLife:
Approximately 70 hours
Clearance:
0.13 L/hr/kg
ExcretionRoute:
Urine (approximately 57%, 17% as unchanged drug) and feces (approximately 14.5%).
Unchanged:
Approximately 17% (in urine)
Pharmacodynamics
OnsetOfAction:
Clinical effects may take several weeks to become apparent.
PeakEffect:
Peak clinical benefit typically observed after several weeks to months of consistent dosing.
DurationOfAction:
Due to its long half-life, once-daily dosing provides sustained acetylcholinesterase inhibition.
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Immediately
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Slow heartbeat
Abnormal heartbeat
Difficulty urinating
Seizures
Heartburn
Severe stomach pain
Vomiting blood or coffee ground-like material
Black, tarry, or bloody stools
New or worsening trouble breathing
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Dizziness, fatigue, or weakness
Diarrhea, upset stomach, or vomiting
Trouble sleeping
Muscle cramps
Decreased appetite
Weight loss
Headache
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Slow heartbeat
Abnormal heartbeat
Difficulty urinating
Seizures
Heartburn
Severe stomach pain
Vomiting blood or coffee ground-like material
Black, tarry, or bloody stools
New or worsening trouble breathing
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or do not go away, contact your doctor:
Dizziness, fatigue, or weakness
Diarrhea, upset stomach, or vomiting
Trouble sleeping
Muscle cramps
Decreased appetite
Weight loss
Headache
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe or persistent nausea, vomiting, or diarrhea
- Fainting or severe dizziness
- Slow or irregular heartbeat
- New or worsening muscle cramps or weakness
- Dark, tarry stools or vomit that looks like coffee grounds (signs of stomach bleeding)
- Difficulty urinating
- Seizures
- Worsening of breathing problems (in patients with asthma or COPD)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the symptoms you experienced as a result of the allergy.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* Any existing health problems, as this medication may interact with certain conditions.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. This drug does not cure Alzheimer's disease, and you should continue to receive regular care from your doctor. If you are pregnant, planning to become pregnant, or are breastfeeding, be sure to discuss this with your doctor, as you will need to carefully weigh the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Severe nausea
- Vomiting
- Salivation
- Sweating
- Bradycardia (slow heart rate)
- Hypotension (low blood pressure)
- Respiratory depression
- Collapse
- Convulsions
- Increased muscle weakness (potentially leading to death if respiratory muscles are involved)
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222. Atropine is a commonly used antidote for cholinergic crisis.
Drug Interactions
Major Interactions
- Anticholinergic agents (e.g., atropine, scopolamine, benztropine): Donepezil may antagonize the effects of anticholinergic drugs.
- Other cholinesterase inhibitors (e.g., rivastigmine, galantamine): Concomitant use may lead to additive cholinergic effects and increased risk of adverse events (e.g., bradycardia, syncope, seizures).
Moderate Interactions
- CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, erythromycin, clarithromycin, ritonavir): May increase donepezil plasma concentrations, increasing risk of adverse effects.
- CYP2D6 inhibitors (e.g., quinidine, fluoxetine, paroxetine): May increase donepezil plasma concentrations, increasing risk of adverse effects.
- CYP3A4 inducers (e.g., rifampin, phenytoin, carbamazepine, phenobarbital): May decrease donepezil plasma concentrations, potentially reducing efficacy.
- CYP2D6 inducers (e.g., rifampin): May decrease donepezil plasma concentrations, potentially reducing efficacy.
- Beta-blockers (e.g., metoprolol, carvedilol): Increased risk of bradycardia and syncope due to additive vagotonic effects.
- NSAIDs (e.g., ibuprofen, naproxen): Increased risk of gastrointestinal bleeding, especially in patients with a history of ulcers.
Monitoring
Baseline Monitoring
Cognitive assessment (e.g., MMSE, ADAS-Cog)
Rationale: To establish baseline cognitive function and track disease progression/response to therapy.
Timing: Prior to initiation of therapy.
Heart rate and rhythm (ECG if clinically indicated)
Rationale: Donepezil can cause bradycardia and syncope, especially in patients with pre-existing cardiac conduction abnormalities.
Timing: Prior to initiation, especially in patients with cardiac history.
Liver function tests (ALT, AST, bilirubin)
Rationale: Donepezil is metabolized by the liver; baseline assessment is prudent, especially if hepatic impairment is suspected.
Timing: Prior to initiation, if clinically indicated.
Routine Monitoring
Cognitive assessment
Frequency: Every 6-12 months, or as clinically indicated.
Target: Improvement or stabilization of cognitive function.
Action Threshold: Significant decline may warrant re-evaluation of therapy or dose adjustment.
Heart rate and blood pressure
Frequency: Periodically, or if patient reports dizziness/syncope.
Target: Within normal limits for the patient.
Action Threshold: Symptomatic bradycardia (<50 bpm) or hypotension may require dose reduction or discontinuation.
Gastrointestinal symptoms (nausea, vomiting, diarrhea)
Frequency: Regularly, especially during dose titration.
Target: Absence or mild, tolerable symptoms.
Action Threshold: Severe or persistent symptoms may require dose reduction or discontinuation.
Weight
Frequency: Periodically
Target: Stable weight
Action Threshold: Significant unintentional weight loss may indicate underlying issues or severe GI side effects.
Symptom Monitoring
- Nausea
- Vomiting
- Diarrhea
- Dizziness
- Headache
- Insomnia
- Muscle cramps
- Fatigue
- Anorexia
- Bradycardia
- Syncope
- Seizures
- GI bleeding (dark stools, coffee-ground emesis)
Special Patient Groups
Pregnancy
Donepezil is classified as Pregnancy Category C. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. There are no adequate and well-controlled studies in pregnant women.
Trimester-Specific Risks:
First Trimester:
Potential for developmental toxicity based on animal studies (no human data).
Second Trimester:
Potential for developmental toxicity based on animal studies (no human data).
Third Trimester:
Potential for developmental toxicity based on animal studies (no human data).
Lactation
Donepezil is excreted in the milk of rats. It is not known whether donepezil is excreted in human milk. Due to the potential for serious adverse reactions in breastfed infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. Lactation risk category L3 (Moderately Safe) suggests caution.
Infant Risk:
Potential for cholinergic effects in the infant (e.g., bradycardia, vomiting, diarrhea).
Pediatric Use
The safety and effectiveness of donepezil in pediatric patients have not been established. Donepezil is not indicated for use in children.
Geriatric Use
Donepezil is primarily used in the geriatric population. No specific dose adjustment is required based solely on age. However, elderly patients may be more susceptible to adverse effects such as bradycardia, syncope, and falls, requiring careful monitoring and slower titration.
Clinical Information
Clinical Pearls
- Administer donepezil at bedtime to minimize the impact of common side effects like nausea and dizziness, which often occur upon initiation.
- Titrate the dose slowly (e.g., 5 mg for 4-6 weeks before increasing to 10 mg) to improve tolerability and reduce gastrointestinal side effects.
- Counsel patients and caregivers on the importance of adherence, as abrupt discontinuation can lead to a rapid decline in cognitive function.
- Monitor for signs of bradycardia and syncope, especially in patients with pre-existing cardiac conditions or those on concomitant medications that can slow heart rate (e.g., beta-blockers).
- Be vigilant for signs of gastrointestinal bleeding, particularly in patients with a history of ulcers or those taking NSAIDs concurrently.
- Donepezil does not cure Alzheimer's disease but may slow the progression of symptoms for a period.
Alternative Therapies
- Rivastigmine (another acetylcholinesterase inhibitor, available orally and transdermally)
- Galantamine (another acetylcholinesterase inhibitor)
- Memantine (an NMDA receptor antagonist, often used in combination with donepezil for moderate to severe Alzheimer's)
Cost & Coverage
Average Cost:
$10 - $50 per 30 tablets (generic 5mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (for generic donepezil)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.