Understanding What Are the Rare Side Effects of Ingrezza?

While somnolence and dry mouth are among the most common side effects reported with Ingrezza, a number of more serious, rare adverse events can occur, such as Neuroleptic Malignant Syndrome (NMS) and severe allergic reactions. Addressing the question, 'What are the rare side effects of Ingrezza?', this article outlines these less-frequent but critical reactions that require immediate medical attention.

Quick Summary

This article details the rare but serious side effects associated with Ingrezza, including life-threatening reactions like Neuroleptic Malignant Syndrome (NMS), significant QT prolongation, severe allergic reactions (angioedema), and worsening depression or parkinsonism.

Key Points

• Black Box Warning: Ingrezza carries a boxed warning for increased risk of depression and suicidal thoughts in patients with Huntington's disease.

• Neuroleptic Malignant Syndrome (NMS): A rare, life-threatening reaction with symptoms including high fever, severe muscle stiffness, and confusion, requiring immediate medical care.

• QT Prolongation: This rare heart rhythm problem can be life-threatening and is more likely in patients with pre-existing heart conditions or those on certain other medications.

• Angioedema: Serious allergic reactions, such as swelling of the face, lips, tongue, or throat, have been reported and necessitate immediate medical attention.

• Drug-Induced Parkinsonism: Ingrezza can cause severe, parkinson-like symptoms, particularly within the first two weeks of starting or increasing the dose, but these often resolve with dose reduction or discontinuation.

• Seizures: Though incidence is unknown, seizures have been reported as a potential rare side effect of Ingrezza.

Understanding Ingrezza's Safety Profile

Ingrezza (valbenazine) is a prescription medication approved for treating adults with tardive dyskinesia (TD) and chorea associated with Huntington's disease (HD). It functions as a reversible inhibitor of vesicular monoamine transporter 2 (VMAT2), helping to regulate dopamine levels in the brain. While common side effects include sleepiness and dry mouth, patients and healthcare providers must be aware of rare, severe reactions. Close monitoring is important throughout treatment.

Neuroleptic Malignant Syndrome (NMS)

Neuroleptic Malignant Syndrome (NMS) is a rare, potentially fatal reaction linked to drugs that reduce dopamine, including Ingrezza. It's a medical emergency.

Symptoms and Management of NMS

NMS symptoms include:

• High fever (hyperpyrexia)
• Severe muscle stiffness
• Confusion or altered mental status
• Irregular pulse or blood pressure, rapid heartbeat
• Increased sweating

If NMS is suspected, stop Ingrezza immediately. Management involves intensive medical support and treating symptoms.

Severe Allergic Reactions (Angioedema)

Rarely, severe allergic reactions like angioedema have been reported after Ingrezza became available. Angioedema is dangerous swelling of the face, lips, tongue, or throat.

Signs of Severe Allergic Reaction

Seek emergency help for:

• Swelling of face, lips, tongue, or throat
• Breathing difficulties
• Hives or severe rash
• Trouble swallowing

Ingrezza must be stopped if this occurs.

QT Prolongation

Ingrezza can affect the heart's electrical cycle (QT interval). While usually not significant at recommended doses, risk increases in certain patients. This rare effect can cause life-threatening irregular heartbeats.

Risk Factors and Symptoms

Higher risk for QT prolongation exists for those with:

• Congenital long QT syndrome
• Other heart issues
• Use of other QT-prolonging medications

Symptoms to note are:

• Fast, slow, or irregular heart rate
• Dizziness, fainting
• Shortness of breath
• Chest pain

Drug-Induced Parkinsonism

Parkinsonism, causing Parkinson's-like symptoms, has been reported with Ingrezza. Symptoms often start within two weeks of beginning or increasing the dose.

Features of Drug-Induced Parkinsonism

Symptoms include:

• Tremors
• Slowed movements
• Muscle stiffness
• Balance problems
• Shuffling walk
• Drooling

Symptoms often improved or resolved when the dose was lowered or stopped.

Depression and Suicidal Ideation in Huntington's Disease Patients

Ingrezza has a boxed warning about increased risk of depression and suicidal thoughts in HD patients. HD patients are already at risk, and Ingrezza may worsen these issues.

Monitoring for Psychiatric Changes

Monitor all patients, especially those with a history of depression or suicide attempts, for new or worsening psychiatric symptoms. Caregivers should report concerns. If severe, stopping Ingrezza may be necessary.

Seizures

Seizures have been reported, though the frequency is unknown. A seizure is a medical emergency.

Comparison of Rare Side Effects: Ingrezza vs. Austedo

Both Ingrezza and Austedo are VMAT2 inhibitors with similar rare, serious side effects.

Rare/Serious Side Effect	Ingrezza	Austedo
Black Box Warning (Depression/Suicidal Thoughts in HD)	Yes	Yes
Neuroleptic Malignant Syndrome (NMS)	Yes	Yes
QT Prolongation	Yes	Yes
Angioedema	Yes	Yes
Severe Parkinsonism	Yes	Yes

Conclusion

Ingrezza is effective for TD and HD-related chorea, but rare serious side effects exist, including NMS, severe allergic reactions, QT prolongation, parkinsonism, and psychiatric changes. Patients and caregivers must watch for these symptoms and seek immediate medical help. Discuss your medical history and medications with your doctor to minimize risk. Consult the FDA website for more details.

This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional regarding your specific medical needs.

Frequently Asked Questions

What is Neuroleptic Malignant Syndrome (NMS)?

NMS is a rare but potentially fatal reaction associated with certain drugs, including Ingrezza. Symptoms include very high fever, severe muscle stiffness, confusion, and changes in heart rate or blood pressure. It is a medical emergency.

Can Ingrezza cause a heart problem?

Yes, Ingrezza may cause QT prolongation, a potentially serious heart rhythm problem, particularly in patients with pre-existing heart conditions or who take other medications that affect heart rhythm. Patients should watch for symptoms like a rapid or irregular heartbeat, dizziness, or fainting.

Is depression a common or rare side effect of Ingrezza?

While depression and suicidal thoughts are rare side effects for most patients, Ingrezza carries a boxed warning for an increased risk of these symptoms in patients with Huntington's disease. Monitoring for psychiatric changes is crucial, especially in this population.

What are the signs of a severe allergic reaction to Ingrezza?

Signs of a severe allergic reaction, such as angioedema, include swelling of the face, lips, tongue, or throat, difficulty breathing, or hives. This can happen at any time and requires immediate emergency medical care.

What is drug-induced parkinsonism, and how does it relate to Ingrezza?

Drug-induced parkinsonism is a movement disorder caused by certain medications, including Ingrezza. It causes symptoms like tremors, slowed movements, and stiff muscles. These symptoms often appear shortly after starting or increasing the dose and may resolve upon stopping or reducing the medication.

Have seizures been reported with Ingrezza use?

According to reports, seizures have been noted as a potential rare adverse event, although the exact incidence is not well-documented. Any seizure should be treated as a medical emergency.

How does Ingrezza compare to Austedo regarding rare side effects?

Both Ingrezza and Austedo are VMAT2 inhibitors used for movement disorders and share similar rare but serious side effects, including a boxed warning for psychiatric risks in HD, NMS, and QT prolongation. Specific individual risks should be discussed with a doctor.