How Do Nonbenzodiazepine Anxiolytics Work?

Nonbenzodiazepine anxiolytics are medications usually prescribed as a second line treatment for anxiety disorders. Nonbenzodiazepine anxiolytics work on the central nervous system to induce mild sedation and relieve anxiety.

Nonbenzodiazepine anxiolytics work by balancing the activity of chemicals (neurotransmitters) in the brain. Nonbenzodiazepine anxiolytics activate or block protein molecules (receptors) on nerve cells (neurons) which stimulate inhibitory or excitatory action in response to signals from the neurotransmitters.

Currently, two nonbenzodiazepine anxiolytics are used to treat anxiety and each works in a different way to relieve symptoms:

• Buspirone: Buspirone enhances the activity of 5HT1A serotonin receptors which are inhibitory and inhibit D2 dopamine receptors, which are excitatory. Serotonin and dopamine are neurotransmitters that regulate many functions including mood and emotions. It is not fully clear how buspirone reduces anxiety, but the effect is thought to be from increased serotonin activity in the anxiety/fear circuitry of the brain. Buspirone has no sedative effects.
• Meprobamate: Meprobamate has an inhibitory effect on the limbic system of the brain, which regulates emotional and behavioral responses. The precise mechanism of meprobamate is unclear but it is believed to stimulate gamma aminobutyric acid (GABA) receptors which are inhibitory. Meprobamate has mild sedative, muscle relaxing and anticonvulsant effects.

Nonbenzodiazepine anxiolytics are oral tablets used in the treatment of the following conditions:

FDA-Approved

• Anxiety
• Anxiety disorders
• Preoperative sedation

Off-label uses:

• Smoking cessation
• Generalized anxiety disorder

Side effects of nonbenzodiazepine anxiolytics may include the following:

• Dizziness
• Somnolence (drowsiness)
• Headache
• Confusion
• Diarrhea
• Nausea
• Vomiting
• Anorexia (loss of appetite)
• Nervousness
• Excitement
• Euphoria
• Insomnia
• Dream disturbances
• Paradoxical reactions
• Suicidal ideation
• Blurred vision
• Visual disturbances
• Increased ocular pressure
• Eye accommodation (focusing) disorder 
• Photophobia (sensitivity to light)
• Tinnitus (ringing in the ears)
• Vertigo
• Myalgia (muscle pain)
• Numbness
• Paresthesia (prickling sensation)
• Akathisia (restlessness)
• Asthenia (weakness)
• Ataxia (impaired coordination, balance and speech)
• Dystonia (involuntary muscle contractions)
• Tremor
• Weakness
• Syncope (fainting)
• Allergic reactions such as:
  • Rash
  • Urticaria (hives)
  • Maculopapular eruption (flat lesions with raised bumps)
  • Bullous dermatosis (skin disease with blisters)
  • Anaphylaxis (severe allergic reaction)
• Alopecia (hair loss)
• Eosinophilia (increased eosinophil count in the blood)
• Edema
• Bruising
• Blood dyscrasias (disorders) such as:
  • Leukopenia (low count of leukocytes in the blood)
  • Agranulocytosis (low granulocytes, immune cells with granules)
  • Aplastic anemia (anemia due to reduced red cell production)
• Nasal congestion
• Sore throat
• Nonspecific chest pain
• Heart failure
• Abnormal ECG
• Palpitations
• Tachyarrhythmia (irregular rapid heartbeat)
• Cardiac dysrhythmia (disturbance in heart rhythm)
• EEG abnormality
• Enuresis (urinary incontinence)
• Rectal bleeding
• Menstrual irregularities
• Galactorrhea (abnormal milk production and leakage)

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of nonbenzodiazepine anxiolytic drugs include:

• buspirone
• meprobamate