Risperidone-GA
Risperidone-GA Uses, Dosage, Side Effects, Food Interaction and all others data.
Risperidone-GA is a selective monoaminergic antagonist having a high affinity for serotoninergic 5-HT2 and dopaminergic D2 receptors. Risperidone-GA binds also to alpha1 adrenergic receptors and with lower affinity, to H1 histamine and alpha2 adrenergic receptors. Risperidone-GA has no affinity for cholinergic receptors. Risperidone-GA, as a potent D2 antagonist, improves the positive symptoms of schizophrenia but causes less depression of motor activity. Balanced central serotonin and dopamine antagonism may reduce extrapyramidal side effect liability and extend the therapeutic activity to the negative and affective symptoms of schizophrenia.
The primary action of risperidone is to decrease dopaminergic and serotonergic pathway activity in the brain, therefore decreasing symptoms of schizophrenia and mood disorders.
Risperidone-GA has a high binding affinity for serotonergic 5-HT2A receptors when compared to dopaminergic D2 receptors in the brain. Risperidone-GA binds to D2 receptors with a lower affinity than first-generation antipsychotic drugs, which bind with very high affinity. A reduction in extrapyramidal symptoms with risperidone, when compared to its predecessors, is likely a result of its moderate affinity for dopaminergic D2 receptors.
| Trade Name | Risperidone-GA |
| Availability | Prescription only |
| Generic | Risperidone |
| Risperidone Other Names | Risperidona, Rispéridone, Risperidone, Risperidonum |
| Related Drugs | Vraylar, fluoxetine, venlafaxine, quetiapine, lamotrigine, Abilify, Prozac, Seroquel, aripiprazole, olanzapine |
| Type | |
| Formula | C23H27FN4O2 |
| Weight | Average: 410.4845 Monoisotopic: 410.211804333 |
| Protein binding | Risperidone and its active metabolite, 9-hydroxyrisperidone, are ~88% and ~77% protein-bound in human plasma, respectively. They each bind to both serum albumin and alpha-1-acid glycoprotein. |
| Groups | Approved, Investigational |
| Therapeutic Class | Atypical neuroleptic drugs |
| Manufacturer | |
| Available Country | Australia |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Risperidone-GA tablet is used for the treatment of acute and chronic schizophrenic psychoses, and other psychotic conditions, in which positive symptoms (such as hallucinations, delusions, thought disturbances, hostility, suspiciousness), and/or negative symptoms (such as blunted affect, emotional and social withdrawal, poverty of speech) are prominent. Risperidone-GA also alleviate affective symptoms (such as depression, guilt feelings, anxiety) associated with schizophrenia. Risperidone-GA is also effective inmaintaining the clinical improvement during continuation therapy in patients who have shown an initial treatment response. Risperidone-GA is in dicated for the treatment of mania in bipolar disorder.
Risperidone-GA is also used to associated treatment for these conditions: Acute Mania, Irritability, Mixed manic depressive episode, Psychosis, Schizophrenia, Acute Manic episode, Agitated psychotic state
How Risperidone-GA works
Though its precise mechanism of action is not fully understood, current focus is on the ability of risperidone to inhibit the D2 dopaminergic receptors and 5-HT2A serotonergic receptors in the brain. Schizophrenia is thought to result from an excess of dopaminergic D2 and serotonergic 5-HT2A activity, resulting in overactivity of central mesolimbic pathways and mesocortical pathways, respectively.
D2 dopaminergic receptors are transiently inhibited by risperidone, reducing dopaminergic neurotransmission, therefore decreasing positive symptoms of schizophrenia, such as delusions and hallucinations. Risperidone-GA binds transiently and with loose affinity to the dopaminergic D2 receptor, with an ideal receptor occupancy of 60-70% for optimal effect. Rapid dissociation of risperidone from the D2 receptors contributes to decreased risk of extrapyramidal symptoms (EPS), which occur with permanent and high occupancy blockade of D2 dopaminergic receptors. Low-affinity binding and rapid dissociation from the D2 receptor distinguish risperidone from the traditional antipsychotic drugs. A higher occupancy rate of D2 receptors is said to increase the risk of extrapyramidal symptoms and is therefore to be avoided.
Increased serotonergic mesocortical activity in schizophrenia results in negative symptoms, such as depression and decreased motivation. The high-affinity binding of risperidone to 5-HT2A receptors leads to a decrease in serotonergic activity. In addition, 5-HT2A receptor blockade results in decreased risk of extrapyramidal symptoms, likely by increasing dopamine release from the frontal cortex, and not the nigrostriatal tract. Dopamine level is therefore not completely inhibited. Through the above mechanisms, both serotonergic and D2 blockade by risperidone are thought to synergistically work to decrease the risk of extrapyramidal symptoms.
Risperidone-GA has also been said to be an antagonist of alpha-1 (α1), alpha-2 (α2), and histamine (H1) receptors.[L1212] Blockade of these receptors is thought to improve symptoms of schizophrenia, however the exact mechanism of action on these receptors is not fully understood at this time.
Dosage
Risperidone-GA dosage
Psychoses: 2 mg in 1-2 divided doses on 1st day then 4 mg in 1-2 divided doses on second day (Slower titration appropriate in some patients); usual dose range 4-6 mg daily; doses above 10 mg daily only if benefit considered to outweigh risk (max. 16 mg daily). Elderly (or in hepatic or renal impairment) initially 1 mg daily in two divided doses increased in steps of 1-2 mg twice daily. Child under 15 years not recommended.
Mania:Initially 2 mg once daily increased if necessary in step of 1 mg daily; usual dose range 1-6 mg daily; Elderly (or in hepatic or renal impairment) initially 1 mg daily in two divided doses increased in steps of 1-2 mg twice daily.
Schizophrenia: Risperidone-GA should be generally administered at 1 mg BID initially, with increases in increments of 1 mg BID on the second and third day, as tolerated, to a target dose of 3 mg BID by the third day. Further dosage adjustments, if indicated, should generally occur at intervals of not less than 1 week. When dosage adjustments are necessary, small dose increments or decrements of 1-2 mg are recommended.
Side Effects
Insomnia, agitation, anxiety, headache, less commonly drowsiness, impaired concentration, fatigue, blurred vision, constipation, nausea and vomiting, dyspepsia, abdominal pain, hyperprolactinaemia, urine incontinence, tachycardia, hypertension, edema, rash, rhinitis, cerebrovascular accident, neurtropenia and thrombocytopenia have been reported.
Toxicity
Symptoms of overdose include lethargy, dystonia/spasm, tachycardia, bradycardia, and seizures. LD50=57.7 mg/kg (rat, oral) and 34 mg/kg (rat, intravenous).
Precaution
Special precaution should be taken in case of preexisting cardiovascular diseases, discontinue use if signs and symptoms of tardive dyskinesia occur, renal and hepatic impairment, elderly epilepsy, Parkinson's disease and in pregnancy.
Interaction
Risperidone-GA May antagonize the effects of levodopa and dopamine agonists. Chronic administration with Carbamazepine reduces plasma clearance of Risperidone-GA. Chronic administration with Clozapine may decrease the clearance of Risperidone-GA. Risperidone-GA may enhance the effects of certain antihypertensives.
Food Interaction
- Take with or without food. Food does not affect the rate or extent of absorption.
[Moderate] GENERALLY AVOID: Risperidone-GA oral solution is not compatible with either tea or cola.
In addition, alcohol may potentiate some of the pharmacologic effects of risperidone.
Use in combination may result in additive central nervous system depression and
MANAGEMENT: Risperidone-GA oral solution should not be mixed with tea or cola.
It may be taken with water, coffee, orange juice, or lowfat milk.
Patients should also be advised to avoid consumption of alcohol.
Risperidone-GA Cholesterol interaction
[Moderate] Atypical antipsychotic drugs have been associated with undesirable alterations in lipid levels.
While all agents in the class have been shown to produce some changes, each drug has its own specific risk profile.
Before or soon after initiation of antipsychotic medication, obtain a fasting lipid profile at baseline and monitor periodically during treatment.
Risperidone-GA Drug Interaction
Major: escitalopramModerate: aripiprazole, lorazepam, duloxetine, divalproex sodium, clonazepam, lamotrigine, lithium, pregabalin, polyethylene glycol 3350, fluoxetine, quetiapine, lisdexamfetamine, alprazolam, sertralineUnknown: amphetamine / dextroamphetamine, omega-3 polyunsaturated fatty acids, acetaminophen, cyanocobalamin, cholecalciferol
Risperidone-GA Disease Interaction
Major: dementia, acute alcohol intoxication, CNS depression, NMS, tardive dyskinesia, liver disease, QT interval prolongation, renal dysfunctionModerate: depression, aspiration, seizure, hematologic abnormalities, hyperglycemia/diabetes, hypotension, lipid alterations, priapism, renal impairment, weight gain, hyperprolactinemia, parkinsonism
Volume of Distribution
The volume of distribution of risperidone is approximately 1 to 2 L/kg.
Elimination Route
Well absorbed. The absolute oral bioavailability of risperidone is 70% (CV=25%). The relative oral bioavailability of risperidone from a tablet is 94% (CV=10%) when compared to a solution.
Half Life
3 hours in extensive metabolizers Up to 20 hours in poor metabolizers
Clearance
Risperidone-GA is cleared by the kidneys. Clearance is decreased in the elderly and those with a creatinine clearance (ClCr) between 15-59 mL/min, in whom clearance is decreased by approximately 60%.
Elimination Route
Risperidone-GA is extensively metabolized in the liver. In healthy elderly subjects, renal clearance of both risperidone and 9-hydroxyrisperidone was decreased, and elimination half-lives are prolonged compared to young healthy subjects.
Pregnancy & Breastfeeding use
Pregnancy: Although, in experimental animals, Risperidone-GA did not show direct reproductive toxicity, some indirect, prolactin- and CNS-mediated effects were observed, No teratogenicity effect of Risperidone-GA was noted in any study. The safety of Risperidone-GA for use during human pregnancy has not been established.
Lactation: In animal studies, Risperidone-GA and 9-hydroxyrisperidone are excreted in the milk. It has been demonstrated that Risperidone-GA and 9-hydroxyrisperidone are also excreted in human breast milk. Therefore, women receiving Risperidone-GA should not breast feed.
Contraindication
Risperidone-GA is contraindicated in patients with a known hypersensitivity to the product.
Acute Overdose
Drowsiness, sedation, tachycardia, hypotension, and extrapyramidal symptoms may occur. In case of severe extrapyramidal symptoms, anticholinergic medication should be administered. Close medical supervision and monitoring should continue until the patient recovers. There is no specific antidote to Risperidone-GA.
Storage Condition
Store in a cool and dry place, protected from light.
Innovators Monograph
You find simplified version here Risperidone-GA
Risperidone-GA contains Risperidone see full prescribing information from innovator Risperidone-GA Monograph, Risperidone-GA MSDS, Risperidone-GA FDA label
FAQ
What is Risperidone-GA used for?
Risperidone-GA is used to treat the symptoms of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions) in adults and teenagers 13 years of age and older.
How safe is Risperidone-GA?
Risperidone-GA is a safe and effective new antipsychotic that has a high binding affinity for both serotonin and dopamine receptors. Several well-designed controlled clinical trials have been conducted to establish the antipsychotic efficacy of Risperidone-GA.
How does Risperidone-GA work?
Risperidone-GA works by affecting the amount of certain chemicals called neurotransmitters that occur naturally in your brain.
What are the common side effects of Risperidone-GA?
Common side effects of Risperidone-GA include:
- nausea.
- vomiting.
- diarrhea.
- constipation.
- heartburn.
- dry mouth.
- increased saliva.
- increased appetite.
Is Risperidone-GA safe during pregnancy?
Risperidone-GA may cause weight gain and problems with blood sugar control in a person who is pregnant. This might increase the chance for gestational diabetes.Risperidone-GA should be used during pregnancy only if the benefit to the mother justifies the potential risk to the fetus.
Is Risperidone-GA safe during breastfeeding?
Risperidone-GA has been found in breast milk in low levels. Doses of up to 6 mg a day have been used during breastfeeding. These doses did not cause side effects or symptoms in a small number of breastfed infants who were exposed to Risperidone-GA only.
Can I drink alcohol with Risperidone-GA?
Avoid drinking alcohol. Dangerous side effects could occur. While you are taking Risperidone-GA, you may be more sensitive to very hot conditions.
Can I drive after taking Risperidone-GA?
Risperidone-GA may cause drowsiness and you should not drive or operate machinery if Risperidone-GA has this effect on you.
When should I take Risperidone-GA?
Risperidone-GA is usually taken once or twice a day with or without food. Take Risperidone-GA at around the same time(s) every day.
How long does Risperidone-GA work?
It can take four to six weeks for Risperidone-GA to have its full effect, but some people get good effects right from the first week. You should stay in touch with your doctor to see how it goes over the first few weeks.
Who should not take Risperidone-GA?
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Does Risperidone-GA shorten my life?
Risperidone-GA has not had a harmful effect on the life expectancy of patients with schizophrenia.
Does Risperidone-GA calm down me?
Risperidone-GA also could calm people down or help them to sleep.
Is Risperidone-GA good for anxiety?
Risperidone-GA and are used to treat anxiety. Risperidone-GA is used off-label in the treatment of anxiety.
How quickly does Risperidone-GA work?
It can take four to six weeks for Risperidone-GA to have its full effect, but some people get good effects right from the first week. You should stay in touch with your doctor to see how it goes over the first few weeks.
Will Risperidone-GA help me sleep?
Risperidone-GA often make people drowsy, but there is little evidence that they actually help you fall or stay asleep.
Can Risperidone-GA make me angry ?
Risperidone-GA has pretty big effects on tantrums, aggression and self-injury
Can Risperidone-GA cause liver damage?
Risperidone-GA and quetiapine are both used as antipsychotics and antidepressants, and have the potential to cause liver damage.
Can Risperidone-GA cause hepatitis?
A single case of autoimmune hepatitis due to Risperidone-GA has been published. There may be some cross reactivity to liver injury between risperidone and quetiapine, but usually not with clozapine and olanzapine.
What happens if I miss a dose of Risperidone-GA?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What happens if I overdose of Risperidone-GA?
Seek emergency medical attention.Overdose symptoms may include severe drowsiness, fast heart rate, feeling light-headed, fainting, and restless muscle movements in your eyes, tongue, jaw, or neck.
What happens if I miss a dose of?
Risperidone-GA is not addictive, but stopping it suddenly can cause problems such as difficulty sleeping, feeling or being sick, sweating, and uncontrollable muscle movements.
