Key takeaways

  • The most common side effects of Aricept (donepezil) include insomnia, nausea, and diarrhea.
  • Aricept is not expected to cause any unique side effects in elderly adults. It’s used to treat dementia associated with Alzheimer’s disease, which typically affects people ages 65 years or older.
  • Some side effects may go away on their own over time. However, if you experience side effects that are persistent or bothersome, your doctor may recommend stopping Aricept.

Aricept can cause certain side effects, though most are mild and temporary, typically lasting only a few days to a couple of weeks. If any of the following side effects persist, become severe, or cause you concern, be sure to speak with your doctor or pharmacist.

The following are common and mild side effects of this medication. For a complete list of possible side effects, refer to Aricept’s prescribing information.

Most frequently reported side effects

In clinical trials, the most common side effects reported by people taking Aricept included:

Other mild side effects

Other mild side effects can also occur with Aricept. While the following list covers many reported symptoms, it is not exhaustive:

To learn more about some of these side effects, see the “Side effect specifics” section.

Experiencing side effects? After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews its side effects. If you develop a side effect while taking this medication and want to report it to the FDA, you can visit MedWatch or call 800-FDA-1088.

Aricept may cause serious side effects. The following list may not include all possible serious side effects of the drug. For more information, see Aricept’s prescribing information.

Serious side effects that have been reported include:

If you develop serious side effects while taking Aricept, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

It’s possible. But in the drug’s clinical trials, most side effects were temporary, lasting a few days or weeks.

However, some side effects may not go away until you stop taking Aricept (donepezil). These side effects are rare but may be serious. Examples include:

If you experience bothersome long-term side effects from Aricept or donepezil, talk with your doctor. They can evaluate your symptoms and recommend the safest methods for managing them.

In clinical trials of 5 or 10 milligrams (mg) of Aricept per day for the treatment of mild to moderate Alzheimer’s disease, the most common side effect was nausea followed by diarrhea and headache.

However, it’s important to note that side effects may vary depending on your dosage of Aricept. If you have questions about what side effects are most common at your specific dose, talk with your doctor or pharmacist.

It’s unlikely. In clinical trials, people who stopped taking Aricept didn’t report specific side effects.

However, it’s important that you do not stop taking Aricept on your own. If you’d like to stop treatment, talk with your doctor first. They’ll recommend the safest way for you to stop taking Aricept.

It’s not clear whether Aricept affects older adults (ages 65 years and older) differently than younger adults. The drug is prescribed to treat Alzheimer’s disease, which mainly affects people ages 65 years and older.

In Aricept’s clinical trials, the same side effects occurred in adults older and younger than 65 years. However, it’s important to note that the average age of people taking the drug was 73 years.

If you have concerns about whether your age may affect Aricept’s side effects, talk with your doctor.

Learn more about some of the side effects Aricept may cause. To find out how often side effects occurred in clinical trials, see the drug’s prescribing information.

Nausea, vomiting, and diarrhea

Nausea, vomiting, and diarrhea are some of the most common side effects of Aricept. In clinical trials, these digestive side effects became more common at higher doses. Nausea and diarrhea were also among the most common reasons people stopped treatment with the drug.

In most cases, these side effects are temporary, lasting up to 3 weeks. They usually go away as you continue Aricept treatment. However, in some cases, they can last longer or become severe. Specifically, these side effects may be more severe if you weigh less than 55 kilograms (kg) or 121 pounds (lb).

Nausea, vomiting, and diarrhea can lead to dehydration. Symptoms of dehydration include:

What you can do

At the start of treatment or after dose changes, your doctor will typically monitor you closely for nausea, vomiting, and diarrhea. If you experience these side effects during treatment, be sure to tell your doctor. They can recommend ways to manage them. For example, if you feel nauseous, try taking small sips of fluid or sucking on ice chips.

You can help prevent dehydration by drinking plenty of fluids. Electrolyte drinks, such as Pedialyte, are good choices for preventing dehydration.

If you experience severe or bothersome symptoms of dehydration, seek medical care right away.

Weight loss

Weight loss was a common symptom reported in clinical trials of Aricept. As with certain other side effects, it was more common at higher doses of the drug. It was also more common in people weighing less than 55 kg (about 121 lb).

In some people, the weight loss with Aricept was significant. This means a person lost more than 5% of their body weight. Significant weight loss can be harmful if you have a low body weight.

What you can do

Your doctor will likely check your weight periodically during your treatment with Aricept, particularly after any dose increases. If you notice any unintentional weight loss, let your doctor know. They can determine what’s causing it and suggest ways to manage it.

Allergic reaction

As with most drugs, Aricept can cause an allergic reaction in some people. However, this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin — typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They can recommend ways to ease your symptoms and determine whether you should keep taking Aricept. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Aricept. This drug may not be the right treatment if you have certain medical conditions or other factors that affect your health.

Tell your doctor if any of the following apply to you:

  • Heart problems: Aricept can cause serious heart problems, including bradycardia (slow heart rate) and heart block. If you already have a heart condition, taking Aricept may increase your risk of this side effect.
  • Lung problems: Aricept may worsen symptoms of certain lung problems, such as asthma or chronic obstructive pulmonary disease.
  • Low body weight: The risk of certain side effects may be higher in adults with low body weight. These side effects may include nausea, vomiting, and weight loss. If you weigh less than 55 kg (about 121 lb), talk with your doctor before taking Aricept.
  • Liver problems: Certain liver problems, such as cirrhosis, may affect how well your body can process Aricept. This is because your liver helps clear the drug from your system. If your liver is damaged, it may take your body longer to process Aricept. This can cause the drug to build up in your system which may increase your risk of side effects.
  • Seizure: Drugs like Aricept may increase the risk of seizure. In addition, Alzheimer’s disease may increase your risk of a seizure. If you’ve had a seizure in the past, let your doctor know.
  • Stomach ulcers or nonsteroidal anti-inflammatory drug (NSAID) use: Aricept can increase the risk of stomach ulcers or gastrointestinal (GI) bleeding. In addition, NSAIDs can cause similar side effects. Taking an NSAID with Aricept can further increase your risk of these side effects.
  • Surgery: Aricept can interact with some anesthesia drugs given during surgery. Before having surgery, it’s important to tell your medical team if you’re taking Aricept. They may advise you to change your treatment plan until after your surgery.
  • Allergic reaction: If you’ve had an allergic reaction to Aricept or any of its ingredients, your doctor will likely not prescribe Aricept for you.
  • Pregnancy or breastfeeding: If you’re pregnant or breastfeeding a child, Aricept may not be safe for you. However, Aricept is prescribed for Alzheimer’s disease, which typically affects people ages 65 years and older. If you’re pregnant or can become pregnant, talk with your doctor before starting this medication.
  • Alcohol consumption: If you drink alcohol, Aricept may not be safe for you to take. This drug is processed through your liver. In some cases, alcohol consumption can damage your liver over time. In turn, this can affect how well your body processes Aricept.

Disclaimer: While Medical News Today strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.