- What is an antidepressant medication?
- What are antidepressants?
- What are selective serotonin reuptake inhibitors (SSRIs)?
- What are the side effects of SSRIs?
- What are examples of SSRIs?
- What are serotonin norepinephrine reuptake inhibitors (SNRIs)?
- What are the side effects and drug interactions for SNRIs?
- What are examples of SNRIs?
- What are examples and side effects of tricyclic antidepressants (TCAs)?
- What are examples and side effects of monoamine oxidase inhibitors (MAOIs)?
- What are names of other antidepressants?
What is an antidepressant medication?
Depression is a serious condition that often can be effectively treated with available therapies. Many antidepressants have been developed over the years. The newer classes of antidepressants are better tolerated and associated with fewer drug interactions than the older class of antidepressants. Side effects and drug interactions are barriers to successful treatment. Some side effects of antidepressants resolve with continued use while other side effects can be managed by dose reduction or adding other therapies. Appropriate management of side effects and avoidance of drugs that may interact with antidepressants may improve the success of antidepressant therapy.
This article discusses side effects and potential drug interactions of the major antidepressant classes.
How do antidepressants work?
Antidepressants are the most prescribed drug for depression. The exact mechanism of action of antidepressants is unknown.
- The prevailing theory is that antidepressants increase the
concentration of one or more brain chemicals (neurotransmitters) that nerves in the brain use to communicate with one
- The neurotransmitters affected by antidepressants are norepinephrine, serotonin, and dopamine.
- The different classes of antidepressants differ in the neurotransmitters they affect. This determines some of their side effects and potential drug interactions.
- All available antidepressants are effective, and for most cases of depression there is no good evidence that any antidepressant is more effective than another.
- Side effects, potential drug interactions, and therapy compliance are major factors that influence a doctor's selection of antidepressants for a patient.
How do selective serotonin reuptake inhibitors (SSRIs) work?
SSRIs are the most widely used class of antidepressants. They work by increasing the level of serotonin in the brain. Unlike MAOIs and TCAs, SSRIs do not significantly affect norepinephrine levels in the brain. SSRIs also have fewer and milder side effects, fewer drug interactions, and are much less likely to be associated with suicide than TCAs.
What are the side effects of SSRIs?
- Headaches: SSRIs cause headaches and dose-related nausea, vomiting, and diarrhea that improve with continued treatment.
- Insomnia, restlessness, agitation: Insomnia, restlessness, and agitation-which decrease over time-also are associated with SSRIs. Insomnia can be treated with low dose (50-100 mg) trazodone (Desyrel) at bedtime and agitation may be managed by reducing the SSRI dose or treating with anti-anxiety drugs.
- Sexual dysfunction: SSRIs also are associated with sexual dysfunction. Symptoms of sexual dysfunction in men may be treated with sildenafil (Viagra), yohimbine (Pausinystalia yohimbe), amantadine (Symmetrel), cyproheptadine, or neostigmine (Prostigmin).
- Weight gain or loss: Over time, weight loss or weight gain has been associated with SSRIs. Patients may experience weight loss initially but quickly regain weight.
What drugs interact with SSRIs?
- Confusion, high blood pressure, tremor, hyperactivity, coma, and death may occur when SSRIs are combined with other drugs that increase brain serotonin levels, for example, MAOIs, TCAs, sumatriptan (Imitrex), linezolid (Zyvox), St John's Wort, tramadol (Ultram), and meperidine (Demerol).
- The risk of gastrointestinal bleeding may be increased when SSRIs are combined with nonsteroidal anti-inflammatory drugs (NSAIDs).
- SSRIs may increase the effect of the blood thinner warfarin (Coumadin, Jantoven), leading to excessive bleeding. Therefore, warfarin therapy, and patients taking NSAIDs should be monitored more frequently with PT/INR testing in individuals who also are taking SSRIs.
What are examples of SSRIs?
- citalopram (Celexa)
- escitalopram (Lexapro)
- fluoxetine (Prozac, Sarafem)
- fluvoxamine (Luvox)
- paroxetine (Paxil, Paxil CR, Pexeva)
- sertraline (Zoloft)
Quick GuidePhysical Symptoms of Depression in Pictures
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