What is buspirone?
Buspirone is an anti-anxiety medication that modulates brain chemicals that give the user a sense of calmness. However, unlike other drugs of this class, its mechanism of action does not imply binding with GABA receptors.
It is used to treat the signs and symptoms of anxiety, such as irritability, fear, tension, dizziness, tachycardia, and other physical symptoms.
It is also used to treat depression. Buspirone has the chemical formula 8- [4- [4- (2-pyrimidinyl) -1-piperazinyl] butyl] -8-azaspiro [4.5] decane-7,9-dione monohydrochloride. Its molecular weight is 422, and it has the following structural formula:
The most used trade for buspirone is BuSpar.
How does buspirone work in the body?
The exact mechanism of action of buspirone is unknown. However, in vitro studies have shown that it has a high affinity for both presynaptic 5HT serotonin and postsynaptic 1A receptor.
Serotonin is a molecule that binds to these receptors and through various experiments has been shown to have a positive influence on our moods and cognition.
Thus, while the exact mechanism of action is unknown, it is believed that the drug maintains a balance of the activity of these receptors and therefore plays a role in improving mood.
Buspirone is also a weak antagonist of dopamine D2 receptors. These receptors are presynaptic receptors, and when they are activated, they decrease the production and release of dopamine.
These receptors are particularly abundant in the nigrostriatal pathway, so when these receptors are blocked, the amount of dopamine in this pathway increases and this also improves mood.
Since its mechanism of action is unique and does not involve binding to GABA receptors, buspirone is the only anxiolytic drug that does not cause sedation.
What are the indications approved by the FDA for Buspirone?
The FDA has approved the use of buspirone for anxiety disorders and symptoms associated with them, such as fear, insomnia, irritability, palpitations, sweaty hands, and other physical signs and symptoms. A selective serotonin reuptake inhibitor (SSRI) augmentation drug has also been indicated for the treatment of depression.
Out-of-label uses include treating the negative symptoms of schizophrenia, hypoactive sexual desire disorder in women, attention deficit hyperactivity disorder and agitation and aggression in elderly patients with dementia.
It is noteworthy that all these outside uses of the label are still under investigation and, therefore, the doctor must first try other drugs, proven in the treatment of these diseases. Buspirone should only be given if the FDA approved medications for these diseases do not show the desired effect.
The recommended initial dose of buspirone to treat general anxiety disorders is 15 mg (7.5 mg, twice daily). However, if the desired effect of the dose is not obtained, it can be increased to a maximum of 60 mg per day. The recommended form of dose increase is that the dose should be increased after 5 mg every two or three days.
While the prescription of the drug for off-label uses, the doctor can use their experience and the severity of the disease, since there are no guidelines for the dosage of these diseases.
In mild liver or moderate to moderate renal failure, the dose of buspirone needs to be adjusted. The reduction of the recommended dose is 25-50%.
In severe kidney or liver disease, the drug must be discontinued because the drug is metabolized by the liver and excreted primarily by the kidneys.
How long does it take for Buspirone to work?
Buspirone has a unique mechanism of action than other anxiolytics. Therefore, its onset of action also differs from other anxiolytics.
While benzodiazepines and barbiturates take only hours to exert their effects, buspirone can take 2 to 4 weeks to fully exert its effect on the body. So this medication is not indicated during short periods of anxiety such as exams.
How long does it remain in the Buspirone system – blood, urine, hair, saliva?
Buspirone remains in the system usually 18-24 hours. Buspirone is excreted up to 63% in 24 hours. It has a half-life of only a few hours. Due to its short half-life, this drug excretes urine, blood, hair, and saliva within 18-24 hours.
Usually, the drug leaves the body as fecal excretion and metabolites. It is absorbed quickly in the body.
Suffers significant first-pass metabolism. When the buspirone levels were verified in the patients after their treatment, the results came out in which it was evident that this drug remains unchanged in the blood only about 1% and this occurs in 2-3 hours. The rest of the drug is eliminated from the body.
When buspirone is administered in the body, 86% of them are bound to plasma proteins. Flurazepam decreases free plasma levels of buspirone in the blood. Flurazepam does this by almost 20%.
For another hand, aspirin increases blood levels of free buspirone. Aspirin raises the levels of free buspirone by almost 23%. Both of these rising and decreasing effects on free blood buspirone levels due to the effect of flurazepam and aspirin are observed in vitro.
This can not be said if similar effects would be observed inside the body or not.
The first-pass metabolism of buspirone is very effective, and its metabolism is mediated by the CYP3A4 enzyme. Any drug that causes any change in the action of the CYP3A4 enzyme will make the change in metabolism and the effects of buspirone in the body.
Buspirone is a fast-acting medication and has a short half-life. This is very beneficial since it prevents the body from the adverse effects of this drug. The short half-life, excreted hair, urinate blood and saliva.
Buspirone is a selective anxiolytic, with minimal CNS depressant effects. It does not affect driving ability and does not have muscle relaxant or anticonvulsant properties.
The drug interacts with 5HT 1Atype of serotonin receptor brain as a partial agonist, but the exact mechanism of this anxiolytic effect is unexplained. Buspirone has a slow onset of action (2-4 weeks).
The development of tolerance is minimal with chronic use, and there is little rebound anxiety or withdrawal symptoms when discontinuing. Buspirone is metabolized by the CYP3A4 enzyme, and its levels in plasma are considerably raised by drugs such as erythromycin and ketoconazole.
Side effects of buspirone include tachycardia, paresthesia, pupillary constriction and GIT anguish. Buspirone has minimal risk of abuse and is not a controlled drug schedule. The drug seems to be safe during pregnancy. However, if a pregnant woman is going to take this medication, then she should inform her doctor about it.
It is chemically not linked to barbiturates, anxiolytics, sedatives or benzodiazepines. Buspirone also has an affinity for D2 receptors in the brain. Other neurotransmitters can also be affected by buspirone. To summarize, due to the low half-life, this drug, i.e., buspirone, exits the system within 24 hours.
Is buspirone not seen in a drug test?
It does not appear on a drug test. Technically speaking, buspirone should never appear on a drug test as something positive. It is always a negative result as far as the buspirone is considered.
But lately, many false positives have appeared, and now this issue is under discussion. If it appears on a drug test result as positive, then it is most likely to appear as the benzodiazepine.
In most cases and false positive results, the substance that causes the false positive result is benzodiazepine. Well, the false positive result may be due to the poor quality of the tests, but it can not be said with certainty, it could be benzodiazepine, this is still under debate.
In all cases in which the result was false positive, the medication appeared as benzodiazepine, but as it is stated that this class of anxiolytic drugs has no connection with the benzodiazepines. This is the complex point in the drug tests of this drug. Some pharmacists now believe that buspirone can show as benzodiazepine in a drug test.
Above all, the result of the drug test for buspirone is negative, which means that it does not show up on the drug test, but only a few cases have been seen in which the buspirone shows up as the benzodiazepines.
Precautions while using buspirone
Buspirone should not be taken during or within 14 days of use of monoamine oxidase inhibitors (MAOI), due to the risk of developing serotonin syndrome (characterized by high blood pressure, fever, sweating, and tremors).
Since buspirone has no proven effectiveness in the treatment of psychotic disorders, it should not be used as a first-line antipsychotic drug.
Buspirone is a drug classified in category B of the FDA. This means that there are not many studies on the safety of buspirone in pregnant women have been carried out. However, animal studies show no harm to the fetus. So if the doctor considers it essential, then buspirone is not contraindicated.
The use of buspirone in breastfeeding mothers remains controversial. An exclusively breast milk 11-week-old infant whose mother took 10 mg of this drug and 300 mg of venlafaxine a day did not show adverse reactions, but since limited information on this topic, the drug should be avoided until it is necessary.
Buspirone Drug Interactions
Medications that are notorious for interacting with buspirone include:
- Monoamine Oxidase Inhibitors (MAOIs)
- Serotonin reuptake inhibitors (SSRIs), such as nefazodone and trazodone
- Drugs used to treat seizures, such as phenytoin and carbamazepine
- Benzodiazepines that are used to treat anxiety and insomnia, such as diazepam
- Muscle relaxants, for example, cyclobenzaprine
- Drugs used to treat fungal infections, including itraconazole and ketoconazole
- Antibiotics, especially erythromycin and rifampicin
- Steroids such as prednisone
- The heartburn drug cimetidine
- The ritonavir drug against HIV
- calcium channel blockers used to treat high blood pressure and chest pain, including
- diltiazem and verapamil
- Haloperidol antipsychotic
If you are in any of the above medications or have recently finished the chronic use of the above drugs, it is advisable to inform your doctor.
- Buspirone may cause drowsiness and confusion. So you should avoid activities that require superior cognitive functions. Therefore, you should not drive, operate dangerous machinery, or participate in any risky activity until you know how buspirone affects you.
- Drinking alcohol while taking buspirone should also be avoided.
- Do not take large amounts of grapefruit juice with buspirone since grapefruit inhibits the liver enzymes responsible for drug metabolism.
Side Effects of Buspirone
Buspirone is an anxiolytic drug that has some side effects as well. Side effects that are observed include chest pain, muscle weakness, confusion, fever, sore throat, lack of coordination of body movements, skin rashes, skin spots, stiff muscles, general body stiffness, Joint stiffness, mental depression, tingling sensation in the feet and hands, sensations of itching and subcutaneously with comfort.
Side effects include blurred vision, unusual tiredness, and weakness of the whole body, cold sweating, problems, sweating, nightmares, insomnia and sleep disturbances, loss of concentration, dry mouth, and sleep tinnitus, ringing in the ears, drowsiness, diarrhea and unusual vivid dreams.
Dermatological side effects also include ecchymosis, rash, itching, cold sweating, thinning of the nails, facial edema, the body easily gets bruised and hives, hot flushes, sweating, rashes, skin blisters and dry conditions, patches of dry skin are observed in case of use of this drug.
Side effects related to the gastrointestinal tract include dry mouth, diarrhea, flatulence, burning of the tongue, anorexic condition of the patient, increased appetite, constipation, vomiting, rectal bleeding.
Cardiovascular system Related problems include tachycardia, heart problems, myocardial infarction, palpitations, hypertension, chest pain and bradycardia.
Side effects include dizziness, dizziness, amnesia, dizziness, tremors, headache, cogwheel stiffness, seizures, ataxia, paresthesias, lack of coordination and numbness.
Patients with severe kidney disease and acute liver disorders should not take buspirone. It is contraindicated in these patients.
If patients are hypersensitive to buspirone hydrochloride, then it should not be taken. Otherwise, it would lead to a severe hypersensitivity reaction in these patients. One thing that is very important is that if the patient has taken any type of monoamine oxidase inhibitor in the last 14 days, then he should not take this medication, ie buspirone.
If the patient takes buspirone along with monoamine oxidase inhibitors, then it is more likely that it would result in high blood pressure.