How Do SSRI Antidepressants Work?

Selective serotonin reuptake inhibitor(SSRI)antidepressantsare the most common medications prescribed to treatdepressionand many otherpsychiatricconditions. SSRIs selectively increase the levels ofserotoninand regulate its activity.

Serotonin is an important natural chemical (neurotransmitter) released bynervecells (neurons)inthebrainto transmit nerve signals. Serotonin plays avitalrole in neurotransmission in thecentralandperipheralnervous systems and regulates virtually all the systems in the body.

Some of the functions of serotonin include regulation ofsleep, digestion,cognition, mood, and behavior. An increase in serotonin levels helps relieveanxietyand reduce depression symptoms.

SSRIs increase serotonin concentration in the space (synapse) between neurons by preventing itsreabsorption(reuptake). Reuptake of neurotransmitters is a natural recyclingprocessafter the completion of neurotransmission. SSRIs prevent serotonin reuptake by inhibiting serotonin transporter (SERT), aproteinin the transmittingneuron.

SSRI antidepressants areoraltablets, capsules or solutions approved by theFDAfor the treatment of the following conditions:

• Majordepressive disorder
• Generalized anxiety disorder
• Obsessive-compulsive disorder
• Bulimia nervosa
• Panic disorder
• Premenstrual dysphoric disorder
• Social phobia/Social anxiety disorder
• Posttraumaticstressdisorder (PTSD)
• Menopausalvasomotorsymptoms/hot flashes

Off-label uses include:

• Alcoholism
• Binge-eating disorder
• Impulsiveaggressivebehavior
• Insomnia
• 纤维肌痛症
• Migraine
• Hot flashes due to hormonalchemotherapy
• Raynaud phenomenon
• Stuttering
• Vasovagal syncope(a sudden drop inheart rateandblood pressurethat leads tofainting)
• Diabetic neuropathy
• Pruritus(itching)
• Orphan designations:
• Body dysmorphic disorder
• Autism

SSRI抗抑郁药的副作用可能包括the following:

• Xerostomia(dry mouth)
• Nausea
• Somnolence(drowsiness)
• Insomnia
• Hyperhidrosis(excessivesweating)
• Headache
• Ejaculationdisorder
• Impotence
• Decreasedlibido
• Anorgasmia(inability to reachorgasm)
• Dysmenorrhea (menstrual crampsandpain)
• Amenorrhea(absence ofmenstruation)
• Diarrhea
• Anorexia(loss of appetite)
• Increased or reduced appetite
• Constipation
• Dyspepsia(indigestion)
• Vomiting
• Abdominal pain
• Flatulence
• Asthenia(weakness)
• Fatigue
• Dizziness
• Lethargy
• Anxiety
• Nervousness
• Agitation
• Akathisia(restlessness)
• Confusion
• Abnormaldreams
• Abnormal thinking
• Emotionallability(mood swings)
• Amnesia(loss ofmemory)
• Maniaorhypomania
• Exacerbationof depression
• Acutepsychosis
• Angerand aggression
• Depersonalization
• Hallucinations
• Nightmares
• Paranoia andpanicreaction
• Suicidalthought and attempt (rare)
• Tremor
• Myoclonus(不untarymusclejerk ortwitch)
• Ataxia(impaired coordination)
• Abnormalgait
• Falls
• Bonefracture
• Trismus(lockjaw)
• Seizures
• Rhinitis(inflammationof thenasal passage)
• Sinusitis(inflammation of the sinuses)
• Flu-likesyndrome
• Fever
• Malaise
• Upper respiratory infection
• Cough
• Yawning
• Increasedsaliva
• Sweating
• Abnormaltaste
• Dysphagia(swallowing difficulties)
• Gastrointestinal(GI)hemorrhage
• Gastroesophageal reflux
• Pancreatitis(inflammation of thepancreas)
• Rectalhemorrhage
• Toothache
• Neck/shoulder pain
• Arthralgia(jointpain)
• Myalgia(muscle pain)
• Back pain
• Migraine
• Mydriasis(dilationof pupils)
• Abnormal vision
• Diplopia(double vision)
• Angle-closure glaucoma(aconditionwith highintraocular pressurethat damages theoptic nerve)
• Nystagmus(involuntaryeyemovement)
• Orthostatic hypotension(bloodpressure drop when standing up from sitting or lying down)
• Vertigo
• Tinnitus(ringing in the ears)
• Dysarthria(speech disorder)
• Paresthesia(pricklingsensation)
• Hypoesthesia (loss of sensation)
• Polyuria(excessive urination)
• Frequent urination
• Urinaryretention
• Dysuria(painful urination)
• Acute renal failure
• Hypersensitive reactions such as:
  • Rash
  • Pruritus (itching)
  • Urticaria(hives)
  • Ecchymosis(skindiscoloration from bleeding underneath)
  • Erythema multiforme(roundlesions like a bullseye)
  • Alopecia(hair loss)
  • Photosensitivity
  • Angioedema(swelling in thetissueunder the skin ormucousmembranes)
  • Stevens-Johnson syndrome(a rare medical emergency with flu-like symptoms and a painful rash)
  • Toxicepidermalnecrolysis (a severe skin condition with widespread redness, skincelldeath, and exfoliation which can lead tosepsis)
  • Anaphylaxis(severeallergic reaction)
• Bruising
• Edema
• Abnormal bleeding (rare)
• Longer blood clotting time
• Reducedblood countconditions such as:
  • Agranulocytosis(lowgranulocytes,immunecells with granules)
  • Anemia(lowred blood cellcount)
  • Aplastic anemia(anemia due to reduced red cell production)
  • Hemolytic anemia(anemia from rapid destruction ofred cells)
  • Leukopenia(low levels ofleukocytes, a type of immune cell)
  • Thrombocytopenia(decrease inplatelet count)
  • Thrombocytopenicpurpura(easy bruising and bleeding due to thrombocytopenia)
• Tachycardia(rapid heartbeat)
• Palpitations
• Hypertension(high blood pressure)
• Chest pain
• Atrial fibrillation
• Bradycardia(slow heartbeat)
• Torsades de Pointes (irregularheartrhythm in which theventriclesbeat faster and out of synchronization with theatria)
• Cardiacfailure
• Myocardial infarction
• Vasodilation
• Flushing
• Cerebrovascular accident
• Hypotension(low blood pressure)
• Deep vein thrombosis(blood clotin thevein)
• Phlebitis(inflammation of the vein)
• Weight change
• Elevatedliverenzymelevels
• Acutehepatitis(rare)
• Livernecrosisand failure
• Dyspnea(shortness of breath)
• Epistaxis(nasalbleeding)
• Pulmonary embolism
• Pulmonary hypertensionof the newborn
• Hyponatremia(low bloodsodium)
• Hypokalemia(low bloodpotassium)
• Hypercholesterolemia(highcholesterolin the blood)
• Dysglycemia (unstableblood sugarlevels) in diabetic people
• Diabetes mellitus
• Risk ofseizurewith concomitantelectroconvulsive therapy(rare)
• Hyperprolactinemia (increase inprolactinlevels)
• Galactorrhea(abnormal milk production and leakage)
• Menorrhagia(prolonged heavymenstrualbleeding)
• Spontaneous abortion
• Priapism(persistent, painful erection)
• Serotonin syndrome
• Syndrome of inappropriate antidiuretic hormonesecretion (SIADH, a disorder which causeswater retention)
• Muscle cramp, stiffness, and weakness
• Extrapyramidal disorders (drug-induced movement disorders)
• Parkinsonism
• Restless legs
• Rhabdomyolysis(breakdown ofskeletal musclecells)

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

Genericand brand names of SSRIantidepressantdrugs include:

• Brisdelle
• Celexa
• citalopram
• escitalopram
• fluoxetine
• fluvoxamine
• Lexapro
• Luvox
• paroxetine
• Paxil
• Paxil CR
• Pexeva
• Prozac
• Sarafem
• sertraline
• Zoloft