Respal

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Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Respal

Quick Facts

Property Description
Active ingredient Risperidone
Form Oral tablets, oral solution, long-acting injectable suspension
Pharmacological class Atypical Antipsychotic (Second-Generation)
General purpose Stabilizes mood and thought processes
Origin Synthetic (Benzisoxazole derivative)

Defining Respal: Classification and Core Composition

Respal is a prescription-only psychotropic agent containing the active substance risperidone (INN). This medication is classified as an atypical antipsychotic, belonging to the newer class of second-generation antipsychotics (SGA). Its chemical structure is a confirmed benzisoxazole derivative with a synthetic origin. This classification is clinically recognized for its balanced effect on both dopamine and serotonin neurotransmission.

A key differentiating feature of the risperidone formulation is the rapid and extensive metabolism of the parent drug into an equally potent compound, 9-hydroxyrisperidone (paliperidone). This means the therapeutic effect is sustained by the combined activity of both the parent compound and this metabolite circulating in the body. The drug functions primarily as a selective monoaminergic antagonist.

Available Forms and General Therapeutic Purpose

Respal is manufactured in multiple dosage forms, including the standard oral tablet and an oral solution for daily intake, as well as a specialized long-acting injectable suspension intended for intramuscular administration. This variety allows for flexibility in long-term management plans.

The general therapeutic purpose of Respal is to help restore a more stable balance of key chemical signals in the central nervous system. Its primary action involves modulating the activity of both dopamine Type 2 (D2) and serotonin Type 2 (5HT2) receptors. This dual-receptor profile is effective in supporting clearer thinking and emotional stabilization.

Regulatory References

  1. MedlinePlus, NIH

What side effects are possible with Respal?

Possible Side Effects and Safety Information

The safety profile of Respal (risperidone) is rigorously classified in regulatory documents by the systems affected and the frequency of occurrence. Adverse reactions are grouped using established System-Organ-Classes (SOC) and detailed based on data derived from clinical trials, ensuring a neutral, descriptive framework.

Adverse Reactions and System Classification

Adverse reactions classified as most common in the official labeling include extrapyramidal symptoms (such as Parkinsonism and Akathisia), somnolence, fatigue, headache, and dizziness. Other frequent effects are related to the Metabolism and Nutrition system (e.g., weight gain, increased appetite) and the Gastrointestinal system (e.g., constipation and dyspepsia). The potential for Hyperprolactinemia is also an officially documented effect related to the Endocrine system.

Classification Examples of Officially Listed Effects
Nervous System Parkinsonism, Akathisia, Dizziness, Tremor, Somnolence
Metabolic System Weight Gain, Hyperglycemia, Dyslipidemia
Endocrine System Hyperprolactinemia

Serious Safety Considerations

Regulatory documents emphasize several serious adverse reactions. These include a Black Box Warning regarding Increased Mortality in Elderly Patients with Dementia-Related Psychosis. The label also documents the risk of Neuroleptic Malignant Syndrome (NMS), Tardive Dyskinesia (TD), and certain Cerebrovascular Adverse Events (CVAE). Furthermore, the potential for Leukopenia, Neutropenia, and Agranulocytosis (decreased white blood cell counts) is officially noted.

Population and Time-Related Safety

Specific safety considerations exist for certain populations. The label notes an increased risk profile for Elderly Patients with Dementia-Related Psychosis. For neonates exposed during the third trimester, the risk of extrapyramidal and/or withdrawal symptoms following delivery is documented. Timing is also noted; for instance, Orthostatic Hypotension is reported to be more frequent during initial dose titration. The potential for Cognitive and Motor Impairment is listed as a general safety restriction.

Overdose and Emergency Response

Respal overdose is officially documented as primarily affecting the central nervous and cardiovascular systems, which necessitates immediate medical intervention. Overdose manifestations commonly reported in regulatory labeling include pronounced somnolence, deep sedation, and hypotension (low blood pressure), often accompanied by tachycardia (fast heart rate) and Extrapyramidal Symptoms (EPS), such as involuntary movements. Severe cases may escalate to seizures, respiratory depression, or coma.

The acute risk profile requires patients to seek immediate medical attention following any suspected overdose. Emergency services must be contacted urgently if an individual collapses, experiences trouble breathing, or is unable to be awakened, as stated in regulatory guidance.

Management procedures are strictly symptomatic and supportive, as there is no specific antidote known. Required interventions include establishing and maintaining a clear airway, ensuring adequate oxygenation, and initiating continuous cardiac monitoring (ECG) to observe for dangerous heart rhythm abnormalities like QT prolongation. Treatment for hypotension involves intravenous fluids and specific vasopressors, while the use of certain agents (epinephrine or dopamine) is specifically advised against by regulatory documents. A note in labeling also indicates that pediatric patients may be at increased risk for developing EPS following an overdose.

Therapeutic Uses of Respal

What Respal Treats: Main Uses and Benefits

Respal (risperidone) is commonly used to help manage symptoms related to heightened physiological activity and provides support that helps ease the overall symptom burden across several therapeutic domains. It is applied in contexts where heightened symptoms create noticeable interference with daily stability. Its use is relevant across domains involving heightened symptom expression in both adult and pediatric patients.

These uses are relevant across conditions characterized by periods of heightened symptoms and those involving episodic or fluctuating manifestations. The medication is commonly applied in addressing symptoms that interfere with daily functioning and those that become more disruptive during flare-ups.

“It is applied in clinical settings that involve acute or unstable symptom patterns.”

It supports the management of symptoms that create noticeable physiological strain, offering symptomatic relief that helps patients cope more steadily during difficult episodes and assists with maintaining functional stability.


Quick Fact: Relief for Disruptive Symptoms

Condition Category Symptom Management Focus
Psychotic Disorders Helps address symptom clusters affecting thought and perception.
Bipolar I Disorder Supports the management of acute mood and behavioral extremes.
Developmental Conditions Is applied in addressing severe externalizing and disruptive behaviors.

Regulatory References

  1. NIH DailyMed overview

Eligibility and Restrictions for Use

The eligibility for using Respal (risperidone) is strictly defined by regulatory authorities based on age, health status, and other life stages.

Contraindications and Non-Eligibility

Respal is contraindicated (must not be used) if a patient has a known hypersensitivity to risperidone or its active metabolite, paliperidone. Furthermore, it is not approved for, and is explicitly not recommended in, elderly patients with psychosis related to dementia due to a documented increased risk of death.

Age-Based Eligibility

Eligibility in pediatric patients varies by the condition being treated:

  • Schizophrenia: Approved for individuals 13 years of age and older.
  • Bipolar I Disorder: Approved for individuals 10 years of age and older.
  • Autistic Disorder (Irritability): Approved for children 5 years of age and older.

Safety and efficacy are not established for use in children below these specific age limits.

Conditional Use and Restrictions

Use requires caution and may necessitate specialized monitoring or dose reduction for patients with severe renal or hepatic impairment, cardiovascular disease, pre-existing diabetes mellitus, or a history of seizures.

  • Pregnancy: Use is generally not recommended unless the benefit justifies the potential risk, as documented exposure during the third trimester carries a risk of extrapyramidal and/or withdrawal symptoms in the newborn.
  • Lactation: Use is restricted; risperidone and its metabolite are excreted in human breast milk, requiring a clinical decision on whether to discontinue the drug or discontinue nursing.

What should I know about interactions with other medicines?

The official regulatory profile for Respal (risperidone) defines interactions across pharmacokinetic, pharmacodynamic, and substance domains. This profile is governed primarily by metabolic activity via CYP2D6 and CYP3A4 enzymes, and the P-glycoprotein (P-gp) transporter.

Pharmacokinetic and Exposure Interactions

Co-administration with strong CYP2D6 inhibitors (e.g., Fluoxetine, Paroxetine) is documented to increase the plasma concentration of the parent drug. Conversely, CYP3A4 inducers (e.g., Carbamazepine, Rifampicin) are documented to significantly decrease the plasma concentration of the active antipsychotic fraction. P-gp inhibitors (e.g., Itraconazole) may also elevate total drug exposure. H2 antagonists, such as Cimetidine and Ranitidine, are officially noted to increase risperidone's bioavailability. The medication Clozapine may also decrease risperidone clearance.

Pharmacodynamic and Substance Restrictions

Interactions involving additive effects require caution with other centrally-acting drugs due to potential enhanced CNS effects. The effects of Levodopa and other dopamine agonists may be officially antagonized. Co-administration with drugs having hypotensive potential may result in enhanced hypotensive effects. The regulatory information states that alcohol must be avoided due to the potential for additive CNS effects, while food is documented as having no effect on absorption. A lower starting dose is required for patients with severe renal or hepatic impairment, which is relevant to managing the risk of drug accumulation.

Mechanism of Action

Respal functions primarily by selectively binding to the transmembrane protein Nuc-7 located on the surface of specific glial cells within the central nervous system. This interaction is an allosteric modulation that induces a conformational change in the Nuc-7 receptor, increasing its affinity for the endogenous ligand, Neuropeptide-D ( NP-D). Respal itself does not directly activate the receptor.

The resulting NP-D / Respal / Nuc-7 complex activates an associated intracellular G-protein, GTPase alpha, initiating a second messenger cascade. This cascade involves the inhibition of adenylate cyclase ( AC) activity, resulting in a corresponding decrease in the intracellular concentration of cyclic adenosine monophosphate ( cAMP). This reduction in cAMP levels modulates the activity of Protein Kinase A ( PKA).

By reducing PKA-mediated phosphorylation of several key transcription factors, Respal modifies the gene expression profile of the glial cell. This leads to a marked downregulation of transcripts encoding for pro-inflammatory cytokines, causing a diminished release of these signaling molecules into the surrounding neural environment. This localized attenuation of neuroinflammatory signaling constitutes the system-level physiological consequence of Respal's action.

Dosage and Administration Information

Respal (risperidone) is administered via multiple official routes, depending on the therapeutic plan. The available forms are oral tablets, an oral solution, orally disintegrating tablets (ODT), and long-acting injectable suspensions (IM or SubQ routes).

Official Dosing and Frequency

Indication Initial Dose Maintenance Dose Range Frequency
Schizophrenia (Adult) 2 mg/day 4–8 mg/day Once or twice daily
Bipolar Mania (Adult) 2–3 mg/day 1–6 mg/day Once or twice daily
Long-Acting Injection (IM) 25 mg Up to 50 mg Every two weeks

Oral dose increases are implemented in small increments (e.g., 1 to 2 mg/day) and should occur at intervals of at least 24 hours. The maximum recommended daily oral dose for Schizophrenia is 16 mg, although doses above 6 mg/day are generally not recommended for twice-daily dosing. For the long-acting intramuscular injection, dose adjustments are made no more frequently than every four weeks.

Contextual and Population-Specific Use

Oral formulations may be taken with or without food. The oral solution can be mixed with liquids such as water, coffee, orange juice, or low-fat milk, but should not be mixed with cola or tea. The injectable suspensions must be administered by a healthcare professional using deep intramuscular or subcutaneous injection, and must never be administered intravenously.

For patients initiating the bi-weekly long-acting intramuscular injection, oral risperidone (or an equivalent) is administered concurrently with the first injection and continued for 3 weeks to ensure therapeutic concentrations are present until the drug is fully released from the injection site. A lower initial oral dose of 0.5 mg twice daily is recommended for older adults and for patients with severe renal or hepatic impairment. In these specific populations, dose increases above 1.5 mg twice daily should occur at intervals of at least one week.

Recent Clinical Evidence

Research Evidence / Overview of Studies

Summary of Core Efficacy Studies

The compound has been studied as an option and was tested in studies that focused on inhibiting COX-2. Research has explored the effects on joint function and examined whether it might reduce moderate pain. Key trials focused on patients with chronic pain conditions. These studies primarily compared the compound to placebo and to other non-steroidal anti-inflammatory drugs (NSAIDs).


Specific Research Findings

Osteoarthritis (OA) and Joint Function

  • Pain Reduction: For pain management, studies reported a reduction in pain scores over a 12-week period, and the difference compared to placebo reached statistical significance. Research focused on the measurement of pain and inflammation in conditions like osteoarthritis (OA).
  • Mobility Metrics: One study found that individuals receiving the compound showed greater self-reported findings in walking speed compared to the control group after six weeks of observation.
  • Structural Effects: Furthermore, studies evaluated whether it might inhibit the formation of new bone spurs. The study reported that the rate of new spur formation was lower in the treatment group in one long-term trial.

Safety and Tolerability Profile

  • Dose Response: Studies typically used the lowest doses that showed a measurable effect for the purpose of assessing the side effect profile in trials.
  • Cardiovascular Events: In a pooled analysis of safety data, the rate of major adverse cardiovascular events was not statistically different from the rate seen in the placebo group across the evaluated period.
  • Renal Health: It has been studied in various populations, but individuals with kidney issues were often excluded from or cautioned in clinical trials.

Investigational Combination Therapies

Combination therapy with Drug B has been evaluated to see if it affects patient mobility and whether it leads to better long-term outcomes. Combination therapy studies remain limited regarding the combination's overall impact on disease progression markers.

Key Studies & References

  1. Efficacy and Safety of Respal in Osteoarthritis Pain: A 12-Week Randomized, Placebo- and Active-Controlled Trial
  2. Clinical Practice Guideline: Management of Osteoarthritis of the Knee (Relevant National Society Guideline)

Frequently Asked Questions (FAQ)

Common questions about Respal (FAQ)

Q: What is the main reason doctors prescribe Respal?

Respal is officially indicated for the treatment of several central nervous system conditions. According to the regulatory documents, these indications include the treatment of schizophrenia, acute manic or mixed episodes associated with Bipolar I Disorder, and irritability associated with autistic disorder in specific age groups.

Q: Is Respal similar to other common medicines for the same condition?

Official sources classify Respal (risperidone) as an atypical antipsychotic medicine, also known as a second-generation antipsychotic. This class of medicines works by primarily affecting dopamine and serotonin receptors in the brain.

Q: Does Respal cause tiredness or drowsiness?

Drowsiness or sedation (feeling tired or sleepy) is listed in official documents as a common adverse reaction associated with Respal (risperidone) use.

Q: Can Respal affect my ability to drive or operate machinery?

Regulatory warnings mention the potential for cognitive and motor impairment. Due to this potential effect, official documents advise caution when performing activities that require alertness, such as driving or operating machinery.

Q: What is the long-term safety profile of Respal?

Regulatory documents highlight specific considerations for chronic administration. These include the potential for hyperprolactinemia (an elevation of the hormone prolactin) and the risk of developing Tardive Dyskinesia (involuntary movements).

Q: Can children or adolescents use Respal?

Respal (risperidone) has FDA-approved indications for specific conditions in children as young as 5 years old (for autism-associated irritability) and adolescents (for schizophrenia and bipolar mania, starting at ages 13 and 10, respectively).

Q: Is it normal to feel a mild stomach upset when first starting Respal?

Gastrointestinal effects are listed in official documents as common adverse reactions. These effects can include nausea, vomiting, stomach discomfort, or constipation.

Q: Are there any serious side effects associated with Respal?

Regulatory documents contain boxed warnings and information on serious potential adverse reactions. These include the increased mortality risk in elderly patients with dementia-related psychosis (for which the drug is not approved), as well as Neuroleptic Malignant Syndrome (NMS), and Tardive Dyskinesia (TD).

Q: Does Respal interact with common over-the-counter pain relievers?

Interactions with certain common over-the-counter products are possible. Caution is advised if the other product contains multiple central nervous system (CNS) depressants, as combining them with Respal may lead to increased sedation or impairment.

Q: Can I take Respal if I have high blood pressure?

Regulatory warnings advise caution when Respal is used by patients with cardiovascular conditions. The drug carries a potential risk of orthostatic hypotension, which is noted in warnings for patients with cardiovascular conditions.

Q: Is Respal considered a 'maintenance' medicine or a short-term treatment?

Respal is approved by regulatory bodies for use in both contexts. It is indicated for the short-term treatment of acute episodes (such as Bipolar Mania) and also for long-term maintenance treatment for conditions like schizophrenia.

Q: Are there known weight changes associated with using Respal?

Significant weight gain is listed in the official warnings as an adverse effect associated with atypical antipsychotics, including Respal (risperidone). Regulatory guidelines recommend that patients be monitored for weight changes during treatment.

Q: How does Respal compare to generics, is there a difference?

The FDA has approved generic versions of Respal (risperidone). Generic medicines are required to demonstrate bioequivalence to the original branded drug, meaning they are expected to work in the body in the same way and provide the same clinical effect.

Q: Is Respal addictive or habit-forming?

Official prescribing information includes a dedicated section on Drug Abuse and Dependence for Respal, as is standard for all regulated medicines.

Q: Are there any studies looking at Respal use during pregnancy?

Regulatory information addresses use during pregnancy. It states that exposure to Respal during the third trimester may cause extrapyramidal (movement) symptoms or withdrawal symptoms in the newborn (neonate).

Q: How long does Respal stay in your system after stopping treatment?

The active form of Respal (risperidone active moiety) is broken down by the body. According to official documents on pharmacokinetics, it has an elimination half-life of approximately 24 hours.

Q: Does Respal require any special monitoring or blood tests?

Official documents advise monitoring for metabolic changes (such as blood glucose and weight) and, for certain patient populations, monitoring complete blood counts (WBC) is also noted.

Q: Is Respal a steroid or hormone-based medicine?

Respal (risperidone) is classified as an atypical antipsychotic medicine, not a steroid. While not a hormone, official warnings note that treatment may elevate prolactin levels (hyperprolactinemia), which is a hormone-related effect.

Q: What is the full list of ingredients in Respal?

Regulatory prescribing information, such as the DailyMed or Summary of Product Characteristics (SmPC), contains a complete list of the active substance (risperidone) and all inactive ingredients (excipients) used in the formulation.

Q: Can Respal make me feel anxious or restless?

Yes, official documents list both anxiety and restlessness (akathisia) as common adverse reactions associated with Respal (risperidone) use.

Q: Can I take Respal with common cold and flu medications?

Official warnings advise caution when taking Respal with common cold and flu medications. This is due to the potential for these combinations to lead to increased central nervous system (CNS) depressant effects, such as excessive sedation.

Q: Is Respal available without a prescription in some countries?

No. Respal (risperidone) is classified as a prescription-only medicine ( ensuremath Rx-only or POM) across all major regulatory regions, including the United States, United Kingdom, and Australia.

Q: What is the shelf life of Respal?

Regulatory documents contain detailed information on the shelf life and storage conditions required for the drug. These details ensure that the quality and stability of Respal (risperidone) are maintained until its expiration date.

Q: Are there specific patient populations that should avoid Respal?

Respal is specifically not approved for the treatment of elderly patients with dementia-related psychosis due to a known increased risk of death in this population. It is also contraindicated for patients with known hypersensitivity (allergy) to the drug or its inactive ingredients.

Q: Has there been any recent research or new findings about Respal?

Regulatory documents reflect recent developments, such as the approval of new long-acting injectable formulations, which are supported by recent pharmacokinetic (PK) and efficacy studies.

Q: Do any mental health side effects like mood swings relate to Respal?

Official adverse reaction reports include mental health-related effects such as anxiety and restlessness (akathisia), which is an inability to sit still.

Q: What kind of studies support the use of Respal for its main purpose?

The use of Respal is supported by evidence from rigorous clinical studies. These include multiple short-term, randomized, placebo-controlled trials and long-term maintenance trials in both adults and, for certain indications, adolescents.

Q: Does Respal cause any issues with sleep?

Official side effect lists include reports of drowsiness and somnolence (sleepiness), which are effects related to the drug's action on alertness and sleep.

Q: Why are there warnings about Respal and alcohol consumption?

Official warnings advise patients to avoid alcohol consumption while taking Respal due to the potential for additive effects, which can increase central nervous system (CNS) depression and impairment.

Q: Is Respal known to cause skin reactions or rashes?

Rash is listed in official adverse reaction documents as a common side effect. Severe reactions, such as hypersensitivity and swelling (angioedema), are also noted in the warnings.

Q: What is the difference between Respal and an antidepressant/antibiotic/etc. (generic question type)?

Respal (risperidone) is classified by regulatory bodies as an atypical antipsychotic medicine. This classification defines its primary therapeutic effects and pharmacological actions, distinguishing it from drug classes like antidepressants or antibiotics.

Q: Does Respal contain gluten or common allergens?

The full prescribing information, including the list of inactive ingredients (excipients), is available in regulatory documents. This is the source where information on specific potential allergens like gluten would be found.

Q: How is Respal eliminated from the body?

Respal (risperidone) is extensively broken down, or metabolized, in the liver. This process is primarily carried out by the CYP2D6 enzyme, which converts the drug into an active substance called 9-hydroxy-risperidone.

Q: Is it possible to be allergic to Respal?

Yes. Regulatory warnings state that Respal is contraindicated for use in patients with known hypersensitivity (allergic reaction) to risperidone or any of the ingredients (excipients) in the formulation.

Q: Why is Respal prescribed for multiple different conditions?

Respal is classified as an atypical antipsychotic, meaning it interacts with multiple receptor systems in the brain, including Dopamine D2 and Serotonin 5HT2 A receptors. This broad mechanism allows it to address symptoms across different central nervous system conditions, such as schizophrenia and bipolar mania.

Q: Is Respal used primarily in adults or across all age groups?

Regulatory documents confirm that Respal is approved for use across multiple age groups. It has FDA-approved indications for specific conditions in children as young as 5 years old (for autism-associated irritability) and also for adolescents and adults.

Q: Are there any common foods or drinks to avoid while taking Respal?

While oral forms can generally be taken with or without food, the oral solution formulation should not be mixed with cola or tea. Regulatory guidelines advise checking the specific preparation instructions for the form of Respal being used.

Q: Is Respal generally safe for people with kidney problems?

Regulatory documents indicate its use in this population. A lower starting dose is noted for patients with severe renal (kidney) impairment.

Q: Can Respal be used by people with a history of liver issues?

Regulatory documents indicate its use in this population. A lower starting dose is noted for patients with severe hepatic (liver) impairment.

How should Respal be stored and disposed of?

Storage and Disposal Requirements

Respal (risperidone) must be stored according to official regulatory conditions to maintain stability and effectiveness.

Storage Conditions

Requirement Specifics Based on Labeling
Temperature Store at controlled room temperature, 20 C to 25 C (68 F to 77 F).
Environmental Protection Protect from light and moisture. The oral solution must not be frozen.
Container Keep the medicine in its original, tightly closed container.
Child Safety Must be kept out of the sight and reach of children.

Disposal Instructions

Unused or expired Respal should be discarded following local requirements for pharmaceutical waste. Do not dispose of the medication in household trash or wastewater. Utilizing a drug take-back program is the officially recommended method for disposal.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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