Risperidone side effects and how to avoid them

Common risperidone side effects | Serious side effects | Weight gain | Gynecomastia | Tardive dyskinesia | Sexual dysfunction | Side effects timeline | Contraindications | Warnings | Interactions | How to avoid side effects | How to treat side effects

Risperidone is a generic prescription drug used to treat schizophrenia and manic episodes due to bipolar disorder. The Food and Drug Administration (FDA) has also approved risperidone to treat irritability in children and adolescents with autism. Many people, however, are more familiar with risperidone’s brand-name version, Risperdal. Risperidone belongs to a family of antipsychotic medications called atypical antipsychotics. Antipsychotics work by blocking dopamine, a neurotransmitter that is responsible for many of the symptoms of schizophrenia and mania. Atypical antipsychotics, though, are less likely to cause some severe side effects than the first generation of antipsychotics. Risperidone does, however, have side effects, and many people taking the drug may experience one or more of them.

Common side effects of risperidone

The most common side effect of risperidone is drowsiness, affecting as many as 3 in 5 people taking the drug. Risperidone’s most common side effects are:

• Drowsiness
• Increased appetite
• Weight gain
• Insomnia
• Fatigue
• Parkinsonism (Parkinson’s disease symptoms: tremor, slowness, muscle stiffness, difficulty balancing)
• Headache
• Vomiting
• Cough
• Constipation
• Anxiety
• Dizziness
• Abdominal pain
• Nausea
• Fever
• Runny nose
• High blood sugar
• Tremor
• Restlessness and compulsive movements
• Elevated prolactin levels
• Acid indigestion
• Nasal congestion
• Excess salivation
• Diarrhea
• Frequent nighttime urination
• Urinary incontinence
• Blurred vision
• Elevated fats and cholesterol
• Involuntary muscle contractions or tightness
• Dry mouth
• Weight gain
• Fatigue
• Skin rash
• Upper respiratory infection
• Cold symptoms
• Throat pain
• Back or muscle pain
• Breast development in men
• Confusion
• Sensitivity to sunlight

Serious side effects of risperidone

The most serious side effects of risperidone are:

• Extrapyramidal symptoms (drug-induced involuntary movements and muscle contractions)
• Fast heartbeat
• High blood pressure
• High fat and cholesterol levels
• Seizures
• Suicidal thoughts 
• Sudden drop in blood pressure when standing (orthostatic hypotension)
• Fainting
• Chest pain
• Diabetes
• Painful or prolonged erections (priapism)
• Trouble swallowing
• Body temperature dysregulation
• Heart rate changes
• Stroke
• Low white blood cell counts
• Neuroleptic malignant syndrome (NMS)
• Severe allergic reactions

Weight gain

Weight gain is a common problem with risperidone as it is with many atypical antipsychotics. As many as 1 in 3 patients report weight gain as a side effect. In controlled trials, people taking risperidone showed an average weight gain of nine pounds after six months and 11 pounds after 12 months of use 

Gynecomastia

Risperidone can increase prolactin levels in the body, more than other antipsychotics. Hyperprolactinemia may have several effects on men, including impotence, erectile dysfunction, decreased sex drive, and breast development (gynecomastia). The exact incidence of gynecomastia due to risperidone is unknown, but it is a delayed side effect that requires weeks or months of treatment to manifest. Breast development is a cosmetic concern but not a health risk. Both sexes, however, are at risk for osteoporosis if prolactin levels stay high for a long time.

Tardive dyskinesia

Tardive dyskinesia and other involuntary muscle movements (called extrapyramidal symptoms or EPS) are a concern with antipsychotics. Consisting of one or more involuntary movements such as tongue rolling, grimacing, lip smacking, and body movements, tardive dyskinesia causes approximately 3% of risperidone patients to quit the drug. The incidence, however, could be as high as 5%. Tardive dyskinesia is typically associated with dosage and duration of treatment but can occur early. Once tardive dyskinesia is a problem, the only solution is to stop the drug. Some people may see improvement a few months after the drug is discontinued, but it could be a lifelong condition in others.

Sexual dysfunction

Because risperidone increases prolactin levels, men and women may see a decline in sex hormones. For women, this will affect libido, arousal, and vaginal dryness. For men, this may lead to decreased libido, impotence, and ejaculation problems. One large study determined the incidence of decreased sexual interest to be 60% among both men and women taking risperidone for a year. Sexual dysfunction was reported by 46% of those patients, making risperidone the antipsychotic most likely to produce sexual dysfunction. If sexual function is a problem, healthcare providers will usually start by reducing the dose or switching to another antipsychotic. In some cases, they may prescribe other medications such as erectile dysfunction drugs to help resolve the problem.

Risperidone side effects in females vs. males

In general, there are no significant differences in side effects between men and women taking risperidone. Elderly women may be more at risk for tardive dyskinesia, and at least one study showed a greater incidence of skin problems in women taking risperidone. That being said, risperidone can increase prolactin levels in the body. Although hyperprolactinemia is not more likely in one sex versus another, this one side effect causes different problems in men and women. Women will experience menstrual problems, vaginal dryness, arousal problems, and milky discharge from their breasts. Men with too much prolactin may experience impotence, ejaculation problems, fertility problems, and enlarged breasts. 

How soon do risperidone side effects start?

Risperidone can start showing side effects after the first dose. It takes about one hour after taking a dose for the medicine to hit its peak levels. Many common side effects such as sleepiness and headache could appear during that time. Some side effects, particularly the most serious side effects, may require days, weeks, or months to become a problem.

How long do risperidone side effects last?

Most people will experience some side effects when taking risperidone. Some will improve over time, but many side effects are related to the duration of treatment. The longer the medicine is taken, the more side effects it will have. However, most of the common side effects will improve when the medication is discontinued. Some, like neuroleptic malignant syndrome, may require treatment to get better. Unfortunately, many risperidone side effects may be long-term or lifelong conditions such as tardive dyskinesia and diabetes.

What are the long-term side effects of risperidone?

Many of risperidone’s side effects are due to long-term use. Involuntary muscle movements, weight gain, metabolic problems, heart problems, and osteoporosis are all problems that occur when the drug is taken continuously over months or years. Some of them may continue to be problems even after the drug is stopped. 

Risperidone contraindications

Risperidone is contraindicated in people who are allergic to risperidone or a similar drug called Invega (paliperidone).

Pregnancy

Taken during the third trimester, risperidone may cause involuntary muscle movements or withdrawal in a newborn. There is no expected risk for birth defects or miscarriage, but healthcare professionals are advised to weigh the pros and cons when prescribing risperidone to pregnant women. 

Breastfeeding

Risperidone is present in breast milk. Though the risk to a nursing infant has not been studied, there have been reports of breastfed infants who are sleepy, jittery, or have involuntary muscle movements when the mother is on risperidone. If risperidone is used while breastfeeding, the baby should be monitored for problems. 

Seniors

Risperidone is used cautiously in older adults and elderly patients because of the increased risk of falls, injuries, and heart problems. Because of potential hazards, risperidone is not used to treat psychosis in people with dementia. Healthcare providers usually start seniors at a low dose and regularly monitor them for blood pressure, heart problems, and other critical indicators during therapy.

Children

Risperidone is approved for use in adolescents with bipolar disorder and children and adolescents with autism. However, children are vulnerable to experiencing aggression and suicidal thoughts, so their behavior will have to be monitored. Excess weight gain is also a risk, so body weight will have to be monitored.

Risperidone warnings

All antipsychotics have risks, so there are a few cautions in using risperidone.

Black box warning

Risperidone’s drug information includes a black box warning that risperidone increases the risk of death when given to elderly patients with dementia.

Cautions

Certain medical conditions might be worsened by risperidone, or they may increase the likelihood and severity of side effects. These include: 

• A history of seizures
• Low sodium
• Parkinson’s or similar neurological disorders
• Cardiovascular diseases such as heart attack, heart failure, or heart rhythm problems
• Cerebrovascular diseases such as stroke
• Diabetes
• Low blood pressure, low blood volume, or dehydration
• A history of blood problems
• Problems with swallowing
• Kidney disease
• Liver disease
• Phenylketonuria (for people taking orally disintegrating tablets)

Body temperature 

Antipsychotics like risperidone interfere with the body’s ability to regulate its internal temperature, so people taking the drug are at risk of both hyperthermia and hypothermia, but hyperthermia is the more likely hazard. People taking risperidone should be cautious about hot and cold ambient temperatures and avoid strenuous exercise.

Abuse and dependence

Risperidone is not considered a drug likely to be abused or to cause physical dependence. It may, however, cause withdrawal when abruptly discontinued. The prescribing healthcare provider will use a steadily decreasing dose when the drug needs to be stopped. 

Overdose

Get medical help or call a poison helpline when too much risperidone has been taken. An overdose will primarily amplify risperidone’s side effects such as drowsiness, sleepiness, low blood pressure, racing heartbeats, and involuntary movements such as twitching.

Risperidone interactions

Some of risperidone’s problems are due to drug interactions, so healthcare providers and patients should be cautious about combining risperidone with: 

• Other antipsychotic drugs
• Central nervous system depressants such as sedatives, barbiturates, anxiety medications, opioids, muscle relaxants, benzodiazepines, marijuana, and alcohol
• Blood pressure medications
• Drugs that block the ability of the body to break down risperidone such as selective serotonin reuptake inhibitors (SSRIs like paroxetine) and azole antifungal drugs
• Drugs that speed up the body’s metabolism of risperidone and decrease its effectiveness such as H2 blockers and some anticonvulsants like carbamazepine or phenytoin.

How to avoid risperidone side effects

Unfortunately, most people will encounter one or more side effects when taking risperidone. Some are avoidable, but many others can be minimized by following a few simple rules.

1. Give the healthcare provider a complete medical history

The surest way to prevent some of the most serious side effects of risperidone is to give the prescriber a complete medical history, including family history, personal history, and all prescription drugs, over-the-counter drugs, and dietary supplements being taken. Some are more important than others such as: 

• Diabetes or a family history of diabetes
• Seizures
• Low blood pressure
• Heart problems
• Stroke
• Low white blood cell counts
• Low sodium
• Problems with swallowing
• Pregnancy or pregnancy plans
• Breastfeeding or plans to breastfeed

2. Take risperidone as directed

Follow the instructions given by the prescriber or written on the prescription label. Do not take more or less of the medicine. If a dose of risperidone is missed, take it when remembered. However, if it’s almost time for the next dose, skip the missed dose and take the next dose as scheduled.

3. Keep all appointments

The prescribing healthcare provider will monitor for potentially serious side effects and may perform blood tests, ECGs, or other tests. Keep these appointments and always tell the prescriber about any problems.

4. Eat a healthy diet

Eating a healthy diet can help prevent or minimize weight gain. A low-fat and reduced carbohydrate diet could help stave off some of the metabolic adverse effects such as diabetes, high cholesterol, or high triglycerides. Ask the prescriber or a nutritionist for a recommended diet.

5. Don’t drink alcohol

Combining risperidone with alcohol, marijuana, sleeping pills, or other sleep-inducing drugs will amplify risperidone side effects such as drowsiness, lightheadedness, and dizziness. All of these raise the risk of falls, injuries, and accidents.

6. Be cautious about driving and other risky activities

Many of risperidone’s side effects raise the risk of potentially life-threatening accidents or injuries when driving, operating machinery, engaging in sports, or other risky activities. Try to avoid these activities until the effects of the drug on alertness and judgment are fully understood.

How to treat side effects of risperidone

Because risperidone is so likely to cause side effects, most people will need to learn how to manage them. Here are some tips.

Drowsiness and dizziness

When sleepiness or dizziness attacks, sit down and stay seated until the problem passes. Stay seated until the attack passes. 

Fainting and lightheadedness

Some people taking risperidone may feel like they’re going to black out whenever they stand up. Again, the best solution is to sit down and stay seated until lightheadedness passes. Then stand up slowly and move slowly to prevent it from happening again. 

Dry mouth

Chewing sugarless gum, sucking on sugarless candy, or just sipping water can help. If the problem is too hard to live with, ask the prescribing healthcare provider for medical advice. 

Sexual dysfunction

If risperidone is causing problems with sex, talk to the prescribing healthcare provider. There may be options like reducing the dose or switching to another antipsychotic.

Sources

• Antipsychotic-induced sexual dysfunction and its management, World Journal of Men’s Health
• Gender differences in the first-year antipsychotic treatment for Chinese first-episode schizophrenia, Neuropsychiatric Disease and Treatment
• Hyperprolactinemia, StatPearls
• Risperidone, Epocrates
• Risperidone drug summary, Prescriber’s Digital Reference
• Risperidone tablet prescribing information, U.S. National Library of Medicine