Buspar Anti-Anxiety Medication
BuSpar is the brand name of the generic drug buspirone, developed by Bristol-Meyers Squibb in 1986 for the treatment of generalized anxiety disorder, or GAD. It is a non-benzodiazepine anxiolytic that acts as a selective partial agonist of the 5-HT1A receptor.
Generalized Anxiety Disorder
Generalized anxiety disorder (GAD) is more prevalent than most people realize. It affects about 9.5 million people over the age of 18 every year and is characterized by chronic and excessive worry. Symptoms of GAD include:
- Constant worry or obsession over either trivial or large problems
- A sense of feeling “on edge”
- Muscle tension or muscle aches
- Trembling, feeling twitchy or being easily startled
- Difficulty sleeping or falling asleep
- Sweating, nausea, or diarrhea
- Shortness of breath or rapid heartbeat
The 5-HT1Areceptors are found in high densities in various areas of the brain including:
- Cerebral cortex
- Raphne nucleus
These receptors are also found in much lower quantities in the basal ganglia and the thymus. The 5-HT1A receptors have several functions including:
- Decreasing blood pressure
- Lowering heart rate
- Inducing peripheral vasodilation (dilating the blood vessels found in the extremities)
- Stimulating the vagus nerve
5-HT1A receptors generally bind with and are activated by the neurotransmitter serotonin. Buspirone binds to these receptors in place of serotonin and activates them, which produces the drug’s antidepressant and anxiolytic effects.
The benzodiazepine class of anxiolytics includes Valium and Xanax, medications that are well-known for producing sedation. Because it is a non-benzodiazepine, one of buspirone’s advantages is that it does not produce sedative effects, yet it has the same efficacy as the benzodiazepines. Valium and Xanax have addictive qualities as well and are listed as controlled substances. Buspirone is not.
Buspirone comes in several different dosages, and the pills are scored so that they can easily be divided (called a dividose). Buspirone is typically taken twice a day and is available in:
The maximum dosage of buspirone is 60 mg per day. However, it is most commonly taken at 15 mg twice a day.
Buspirone is metabolized by the liver and excreted in both the urine and the feces. It has a half-life of approximately two to three hours. This means after the medication reaches its peak efficacy, the concentration of the drug in the bloodstream will reach half of its original strength in two to three hours.
Contraindications of Buspirone
If you have hypersensitivity or allergy to buspirone or any other drugs in its class, you should avoid taking the medication.
Anyone with hepatic (liver) or renal (kidney) impairment or failure should not take buspirone. MAO inhibitors should not be taken within 14 days of buspirone. Other medications that should be avoided include:
- HIV protease inhibitors
There are a number of medications that can interact with buspirone, but that can be safely taken with it; however, there are too many to list. If you are taking any medications, it is imperative that you discuss these with your doctor prior to starting ANY new medication.
Grapefruit should be avoided when taking buspirone. Grapefruit contains furanocoumarins derivatives. These interfere with hepatic and intestinal enzymes (specifically cytochrome P450 isoform CYP3A4). Bioactive compounds in grapefruit juice can also interfere with P-glycoprotein and organic anion transporting polypeptides (OATPs).
Essentially, this means that grapefruit changes the way the pill is digested in the intestines which can cause more of the medication to be bioavailable at one time. In other words, it could lead to an overdose. If you take buspirone on a regular basis, you should avoid consuming grapefruit and drinking grapefruit juice.
Side Effects of BuSpar
As with any medication, there are side effects. Buspirone has a number of different adverse reactions, but substantially less than many antidepressants. Some of the more serious reactions include:
- Serotonin syndrome (an overdose of the neurotransmitter serotonin, also known as serotonin storm)
- Akathisia (an inability to remain motionless because of the inner sensation of restlessness. The best example of this is restless leg syndrome or RLS.)
- Extrapyramidal symptoms (any of the various movement disorders such as akathisia)
- Tardive dyskinesia (involuntary, repetitive body movements with a slow or belated onset)
- Dystonia (a neurological movement disorder in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures)
Treatment for GAD
Treatment for GAD can involve cognitive behavioral therapy, which is the most common psychotherapy for the disorder or other types of psychotherapy including:
- Acceptance and commitment therapy
- Intolerance of uncertainty therapy
- Motivational interviewing.
Medications used to treat GAD include:
- Antidepressants (Zoloft, Paxil, Prozac)
- Any of the benzodiazepine class (Valium, Xanax, Ativan, Klonopin)
The more common side effects include:
- Xerostomia (dry mouth, aka “cottonmouth”)
- Impaired concentration
- Blurred vision
- Abdominal pain
It bears repeating that if you are currently taking any medications you should tell your physician what you are taking prior to starting buspirone (or any other medication). If you are already taking buspirone and you notice any of the above side effects, contact your physician immediately.
Questions & Answers
© 2013 Melissa Flagg COA OSC