Central Nervous System Regulation, Mood, and Cognition
Central Nervous System Regulation, Mood, and Cognition
8.7 Antidepressants
Antidepressants are used to treat depression and other mental health disorders, as well as other medical conditions such as migraine headaches, chronic pain, and premenstrual syndrome. Antidepressants increase levels of neurotransmitters in the CNS, including serotonin (5-HT), dopamine, and norepinephrine. Treatment is based on the belief that alterations in the levels of these neurotransmitters are responsible for causing depression.[1]
This module will discuss four classes of antidepressants: tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and monoamine oxidase inhibitors (MAOIs). These medications are compared in Table 8.7.
TCAs and MAOIs are referred to as first-generation antidepressants because they were first marketed in the 1950s. SSRIs, SNRIs, and other miscellaneous medications such as bupropion are called second-generation antidepressants and are popular because of fewer side effects like sedation, hypotension, anticholinergic effects, or cardiotoxicity.[2]
Safety warnings (Black Box) are in place for all classes of antidepressants used with children, adolescents, and young adults for a higher risk of suicide. All clients receiving antidepressants should be monitored for signs of worsening depression or changing behavior, especially when the medication is started or dosages are changed.
For more information on different types of anti-depressants, watch this video.
Pharmacology – Antidepressants, SSRI, MAIO, TCA, SNRIs by Simple Nursing, is licensed under a Standard YouTube license
Tricyclic Antidepressants
Tricyclic antidepressants (TCAs) were one of the original first-generation antidepressants. Due to the popularity of SSRIs and SNRIs, TCAs are now more commonly used to treat neuropathic pain and insomnia.
Mechanism of Action
TCAs tend to have sedative and anticholinergic effects. They act by inhibiting presynaptic reuptake of NE and 5-HT into nerves. The choice of TCA depends on individual response and tolerance to the drug.
Indications for Use
TCAs are used to treat depression, chronic neuropathic pain, and insomnia.
Nursing Considerations Across the Lifespan
TCAs are often administered at bedtime due to sedating effects and are contraindicated with MAOIs.
Geriatric clients are particularly sensitive to the anticholinergic side effects of tricyclic antidepressants. Peripheral anticholinergic effects include tachycardia, urinary retention, constipation, dry mouth, blurred vision, and exacerbation of narrow-angle glaucoma. Central nervous system anticholinergic effects include cognitive impairment, psychomotor slowing, confusion, sedation, and delirium. Elderly clients taking amitriptyline may be at increased risk for falls. Elderly clients should be started on low doses of amitriptyline and observed closely.
After prolonged administration, abrupt cessation of treatment ma