The 10 Fanapt Side Effects to Watch Out for - GoodRx (2024)

Fanapt (iloperidone) is a brand-name oral medication that’s FDA approved to treat schizophrenia in adults. It’s part of a group of medications known as atypical antipsychotics.

Like all atypical antipsychotics, Fanapt has potential side effects to be aware of. Some Fanapt side effects are mild. But others can be more serious, and may require immediate medical attention. Here, we’ll cover 10 Fanapt side effects you should know about and how you might manage them. But keep in mind, this isn’t a complete list. So before starting Fanapt, talk to your healthcare provider about the risks and benefits.

1. Dizziness

In studies, dizziness was the most common Fanapt side effect. This is a dose-related side effect, meaning it's more likely with higher doses of Fanapt.

Along with dizziness, Fanapt can also make you feel less coordinated and affect your motor skills. Additionally, taking Fanapt with certain other medications and substances that affect the brain can worsen dizziness. A few examples include:

• Opioids, like hydrocodone/acetaminophen and tramadol (Ultram)

• Benzodiazepines, like diazepam (Valium) and alprazolam (Xanax)

• Sleep medications, like zolpidem (Ambien, Edluar) and eszopiclone (Lunesta)

• Alcohol

It’s best to avoid Fanapt with other medications that cause dizziness. If you experience any falls as a result of dizziness, let your provider know immediately. Falls can lead to injuries like bone fractures. If you’re experiencing dizziness, your provider may recommend a lower dose. Or they may suggest a different antipsychotic.

2. Tiredness

Tiredness is also a common side effect of Fanapt. Like dizziness, it’s more likely to happen with higher doses.

When you first start taking Fanapt (or after a dose increase), it’s best to avoid doing any activities that require alertness. This includes driving. Once you see how Fanapt affects you, you may be able to resume these activities.

Fanapt is usually taken twice a day. Therefore, it’s typically unavoidable that you’ll need to take a dose in the morning. If this makes you feel excessively tired throughout the day, contact your healthcare provider. They may need to lower your dose or switch you to another medication.

3. Dry mouth

Dry mouth can also occur with Fanapt. If you’ve ever experienced dry mouth, you know it can be uncomfortable. It can make it hard to enjoy food and lead to long-term complications like dental problems.

Medications are the most common cause of dry mouth. But other things can make it worse. For example, some research shows that alcohol, caffeine, and tobacco can lead to dry mouth. To manage your dry mouth at home, try cutting back on these things. You can also try to relieve dry mouth by sipping cool liquids throughout the day or chewing sugar-free gum with xylitol. Saliva substitutes like Biotene or BioXtra may also help with dry mouth. They’re available over the counter (OTC).

If you’re experiencing dry mouth, make sure to take care of your teeth to prevent long-term dental problems. This includes brushing your teeth twice a day and flossing daily. If dry mouth continues or worsens, contact your healthcare provider. They can help you decide what to do next.

4. Stuffy nose

A stuffy nose (nasal congestion) can occur with Fanapt. It’s not as common as dizziness, tiredness, or dry mouth, but it’s possible. And it’s more common with higher doses.

Nasal congestion happens when the passageways in your nose are blocked. Treatment involves opening up these passageways and reducing swelling.

Most nasal congestion can be managed with OTC treatment options. One medication-free way is to use a saline nasal wash, like a neti pot. Other OTC options include oral medications like pseudoephedrine (Sudafed) or phenylephrine (Sudafed PE). Nasal decongestant sprays like oxymetazoline (Afrin) could also be considered for short-term use (3 days or less).

Don’t start any of these products without checking in with your healthcare provider. Depending on your other medications and medical conditions, some of these OTC products may not be the best choice for you.

5. Low blood pressure

While taking Fanapt, it’s possible for your blood pressure to drop when you change positions. This is called orthostatic hypotension. It can happen when going from lying down to standing, for example.

People with orthostatic hypotension may feel dizzy or lightheaded after changing positions. You may also feel your heart beat faster and feel like you’re going to pass out. Usually, these feelings go away after a few moments. But sometimes these feelings can lead to fainting and falls. Changing positions slowly can help you avoid orthostatic hypotension.

If you have existing heart problems or health conditions that make it more likely to experience low blood pressure, your healthcare provider may ask you to monitor your blood pressure at home. This is also true if you take blood pressure medications. Examples include amlodipine (Norvasc), hydrochlorothiazide (Microzide), and lisinopril (Prinivil, Zestril).

6. Heart problems

Fanapt may raise your risk of developing an abnormal heart rhythm (arrhythmia). It does this by making the QT interval longer. The QT interval is the period of rest during a heartbeat.

Certain health conditions can increase your risk of arrhythmia. This includes a recent heart attack, slow heart rate (bradycardia), and low potassium or magnesium levels. Taking Fanapt with other medications that can prolong the QT interval can also make arrhythmia more likely. This includes macrolide antibiotics, antiarrhythmic medications, and some other antipsychotics.

Fanapt shouldn’t be taken with medications that prolong the QT interval. Before starting Fanapt, review your list of medications with your pharmacist and healthcare provider. They’ll help you check for medications that prolong the QT interval.

It’s important to note that besides the risk of arrhythmia, Fanapt can cause heart problems in older people. Fanapt has a black box warning for an increased risk of death in older people with dementia. Black box warnings are the most severe warning the FDA gives to a medication. In studies, Fanapt was linked to heart problems and stroke in older people with dementia. For these reasons, this group shouldn’t take Fanapt.

7. Neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is a serious Fanapt side effect. It’s rare but can be fatal if not managed quickly. Antipsychotics are the most common medications to cause NMS.

The four most common symptoms of NMS are:

• Confusion

• Fever

• Rigid muscles

• Abnormal changes in heart rate, blood pressure, and breathing patterns

If you think you’re experiencing symptoms of NMS, seek immediate medical care. If it’s determined that you have NMS, Fanapt will be stopped and you’ll receive treatment for your symptoms.

8. Metabolic changes

Antipsychotics are known for their ability to cause metabolic changes. Some of these changes include high blood sugar, high cholesterol, and weight gain. Having high blood sugar over a long period of time can increase your risk of diabetes.

If you experience weight gain from Fanapt, you may be able to manage it through a healthy diet and exercise. Your healthcare provider will likely check your blood sugar and cholesterol levels before and during treatment with Fanapt. If you already have diabetes, your blood sugars will be watched extra closely.

9. Movement problems

Fanapt can cause movement issues known as extrapyramidal symptoms (EPS). EPS are common with antipsychotics, though they tend to be less common with atypical antipsychotics like Fanapt.

The labeling for Fanapt contains a warning about tardive dyskinesia (TD), a form of EPS. It’s a condition of involuntary, uncontrollable movements. The risk of TD may be higher in older adults. Your risk may also be greater with higher doses and using Fanapt for longer periods. Various uncontrollable movements that can occur with TD include swaying from side to side, swinging your arms, and facial movements like blinking, frowning, chewing.

Luckily, Fanapt is one of the antipsychotics that’s less likely to cause TD. But if you develop symptoms of TD, your healthcare provider may consider stopping it. This may reverse the symptoms of TD. But for some people, symptoms don’t completely go away.

If you develop symptoms of TD, let your healthcare provider know right away. They can help you decide what to do next.

10. High prolactin levels

Fanapt can raise the levels of a hormone in the body called prolactin. Prolactin is the hormone that allows women to breastfeed. High prolactin levels can impact fertility, sexual function, and your mood.

Your healthcare provider may monitor prolactin levels throughout treatment with Fanapt. If your levels are high, they may lower your dose. Or they may switch you to another antipsychotic that might be less likely to cause high prolactin.