From the Guidelines
Donepezil (Aricept) is known to cause several side effects, with the most frequent being gastrointestinal issues such as nausea, vomiting, diarrhea, and loss of appetite, as reported in studies 1. The side effects of donepezil can be attributed to its mechanism of action, which involves inhibiting the enzyme acetylcholinesterase, leading to an increase in acetylcholine levels in the brain and body. This increase in acetylcholine affects not only cognitive function but also other body systems where acetylcholine acts as a neurotransmitter.
Common Side Effects
- Gastrointestinal issues: nausea, vomiting, diarrhea, and loss of appetite
- Headaches
- Dizziness
- Insomnia
- Fatigue
- Muscle cramps
- Abnormal dreams
Less Common but Serious Side Effects
- Slow heart rate (bradycardia)
- Fainting
- Seizures
- Difficulty urinating
- Worsening of certain conditions like asthma or ulcers As noted in the study 1, the effect sizes for these adverse effects were statistically significant, with diarrhea and nausea being reported most frequently. The study also found that the quality of reporting harms was low to moderate in most trials.
Minimizing Side Effects
Starting with a lower dose (typically 5mg daily) and gradually increasing to 10mg after 4-6 weeks can help minimize these effects, as suggested by clinical practice 1. Patients should take donepezil in the evening before bedtime to reduce daytime side effects and should contact their healthcare provider if side effects are severe or persistent.
From the FDA Drug Label
Donepezil hydrochloride tablets may cause the following serious side effects: slow heartbeat and fainting. This happens more often in people with heart problems. more stomach acid. This raises the chance of ulcers and bleeding, especially when taking donepezil hydrochloride tablets 23 mg The risk is higher for people who have had ulcers, or take aspirin or other NSAIDs. worsening of lung problems in people with asthma or other lung disease. seizures. difficulty passing urine. The most common side effects of donepezil hydrochloride tablets are: nausea diarrhea not sleeping well vomiting muscle cramps feeling tired not wanting to eat
The side effects of donepezil (Aricept) include:
- Serious side effects:
- Slow heartbeat and fainting
- Increased stomach acid, which can lead to ulcers and bleeding
- Worsening of lung problems in people with asthma or other lung disease
- Seizures
- Difficulty passing urine
- Common side effects:
- Nausea
- Diarrhea
- Insomnia
- Vomiting
- Muscle cramps
- Fatigue
- Loss of appetite 2
From the Research
Side Effects of Donepezil
The side effects of donepezil, a medication used to treat Alzheimer's disease, have been studied in several clinical trials. The most common adverse events associated with donepezil include:
Cholinergic Side Effects
Donepezil is a cholinesterase inhibitor, and as such, it can cause cholinergic side effects, which are related to the increase in acetylcholine levels in the body. These side effects are generally mild and transient, but can be more severe in some cases 3, 4.
Serious Adverse Events
The incidence of serious adverse events was generally similar between donepezil and placebo in short-term trials, with 4-10% of patients experiencing serious events 3. However, in a long-term trial, 26% of patients receiving donepezil reported serious events over a 98-week period 3.
Hepatotoxicity
There is no evidence of hepatotoxicity associated with donepezil, which is a significant advantage over other cholinesterase inhibitors such as tacrine 3, 4, 5.
Withdrawal Due to Adverse Events
The withdrawal rate due to adverse events was higher in patients receiving donepezil 10 mg/day compared to those receiving placebo, with 11% of patients withdrawing due to an adverse event 5.