Some Side Effects
Selective serotonin reuptake inhibitors (SSRIs)
Sexual dysfunction (primarily, delayed orgasm but also loss of desire and erectile dysfunction Erectile Dysfunction (ED) Erectile dysfunction (ED) is the inability to attain or sustain an erection satisfactory for sexual intercourse. (See also Overview of Sexual Dysfunction in Men.) Every man occasionally has... read more in some people), nausea, diarrhea, headache, weight loss (short-term), weight gain (long-term), discontinuation syndrome*, forgetfulness, blunting of emotions, and easy bruising
SSRIs are the most commonly used class of antidepressants. They are also effective for generalized anxiety disorder Generalized Anxiety Disorder Generalized anxiety disorder consists of excessive nervousness and worry about a number of activities or events. People have anxiety more days than not over a period of 6 months or longer. People... read more , obsessive-compulsive disorder Obsessive-Compulsive Disorder (OCD) Obsessive-compulsive disorder is characterized by obsessions, compulsions, or both. Obsessions are recurring, persistent, unwanted, anxiety-provoking, intrusive ideas, images, or urges. Compulsions... read more , panic disorder Panic Attacks and Panic Disorder A panic attack is a brief period of extreme distress, anxiety, or fear that begins suddenly and is accompanied by physical and/or emotional symptoms. Panic disorder involves recurrent panic... read more , phobic disorder Specific Phobic Disorders Specific phobic disorders involve persistent, unrealistic, intense anxiety about and fear of specific situations, circumstances, or objects. The anxiety caused by a phobic disorder can interfere... read more , posttraumatic stress disorder Posttraumatic Stress Disorder (PTSD) Posttraumatic stress disorder (PTSD) involves intense, unpleasant, and dysfunctional reactions beginning after an overwhelming traumatic event. Events that threaten death or serious injury can... read more , premenstrual dysphoric disorder Premenstrual dysphoric disorder A short discussion of prolonged grief disorder. Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to... read more , and bulimia Bulimia Nervosa Bulimia nervosa is an eating disorder characterized by the repeated rapid consumption of large amounts of food (binge eating), followed by attempts to compensate for the excess food consumed... read more .
Toxicity due to overdosage is less serious than that with other antidepressants.
Norepinephrine-dopamine reuptake inhibitors
Headache, agitation, discontinuation syndrome*, high blood pressure in a few people, and rarely seizures
Bupropion is useful for depressed people who also have attention-deficit/hyperactivity disorder Attention-Deficit/Hyperactivity Disorder (ADHD) Attention-deficit/hyperactivity disorder (ADHD) is poor or short attention span and/or excessive activity and impulsiveness inappropriate for the child’s age that interferes with functioning... read more or cocaine use disorder Cocaine Cocaine is an addictive stimulant drug made from leaves of the coca plant. Cocaine is a strong stimulant that increases alertness, causes euphoria, and makes people feel powerful. High doses... read more and those trying to stop smoking Smoking Cessation While often very challenging, quitting smoking is one of the most important things smokers can do for their health. Quitting smoking brings immediate health benefits that increase over time... read more . Bupropion does not cause sexual dysfunction.
Serotonin modulators (5-HT2 blockers)
Drowsiness and weight gain
Mirtazapine does not cause nausea or sexual dysfunction.
Prolonged drowsiness, painful and persistent erection ( priapism Persistent Erection Persistent erection (priapism) is a painful, persistent, abnormal erection unaccompanied by sexual desire or excitation. It is most common in boys aged 5 to 10 years and in men aged 20 to 50... read more ), and an excessive decrease in blood pressure when a person stands
Trazodone is most often given at bedtime to people who have both depression and insomnia Insomnia and Excessive Daytime Sleepiness (EDS) The most commonly reported sleep-related problems are insomnia and excessive daytime sleepiness. Insomnia is difficulty falling asleep or staying asleep, waking up early, or a disturbance in... read more .
Serotonin-norepinephrine reuptake inhibitors
Nausea, dry mouth, discontinuation syndrome*, and, if high doses are taken, an increase in blood pressure
Most of the side effects can be prevented or minimized when low doses are used and when changes in dosages are made slowly.
Heterocyclic (including tricyclic) antidepressants
Drowsiness, weight gain, increased heart rate and decreased blood pressure when a person stands ( orthostatic hypotension Dizziness or Light-Headedness When Standing Up In some people, particularly older people, blood pressure drops excessively when they sit or stand up (a condition called orthostatic or postural hypotension). Symptoms of faintness, light-headedness... read more ), dry mouth, confusion, blurred vision, constipation, difficulty starting to urinate, delayed orgasm, and discontinuation syndrome*
With clomipramine and maprotiline, seizures
These drugs are usually not prescribed for older people because side effects are usually more pronounced in them.
Overdosage can cause serious, potentially life-threatening toxicity.
Monoamine oxidase inhibitors (MAOIs)
Insomnia, nausea, weight gain, sexual dysfunction (loss of desire, delayed orgasm, and erectile dysfunction Erectile Dysfunction (ED) Erectile dysfunction (ED) is the inability to attain or sustain an erection satisfactory for sexual intercourse. (See also Overview of Sexual Dysfunction in Men.) Every man occasionally has... read more ), pins-and-needles sensation, dizziness, decreased blood pressure (particularly when a person stands), and discontinuation syndrome*
People who take these drugs must follow dietary restrictions and avoid using certain drugs to avoid a serious reaction involving a sudden, severe increase in blood pressure with a severe, throbbing headache (hypertensive crisis).
Selegiline is available as a patch. With the patch, people do not have to follow the dietary restrictions unless the patch contains a high dose.
Nervousness, tremor, insomnia, and dry mouth
These drugs are usually used with antidepressants. Used alone, they are usually ineffective as antidepressants.
Headache, nausea, and diarrhea
Agomelatine has fewer side effects than most antidepressants. It does not cause daytime drowsiness, insomnia, weight gain, or sexual dysfunction.
Agomelatine may increase liver enzyme levels. These levels should be measured before therapy is started and every 6 weeks thereafter.
Dizziness, increased blood pressure, feeling of detachment
Esketamine is related to the anesthetic ketamine.
Esketamine is used in combination with other oral antidepressants for treatment-resistant depression.
Esketamine is available as a nasal spray
* Discontinuation syndrome consists of dizziness, anxiety, irritability, fatigue, nausea, chills, and muscle aches that occur when a drug is stopped abruptly.