The foremost significant division of antidepressants marketed in recent times would be the selective serotonin reuptake inhibitors (SSRIs). The six SSRIs used in the united states of america are citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil), and sertraline (Zoloft). The leading some uses for the SSRIs include unipolar and bipolar major depression any of course your the anxiety attacks. However, controlled trials also support the utilization of SSRIs inside the treatment of other psychiatric disorders including dysthymia, premenstrual dysphoria, bulimia nervosa, obesity, borderline personality disorder, alcoholism, rheumatic pain, and migraine headache.
Among the SSRIs, you will find more similarities than differences. Although all SSRI drugs possess the same the mechanism of action, each SSRI consists of a slightly different pharmacological and pharmacokinetic characteristics. This leads to differences among the SSRIs with their half-lives, clinical activity, unwanted effects, and drug interactions. You will find differences between SSRIs that could be clinically significant.
The very first drug inside the SSRI class was Prozac (Fluoxetine), which hit the United States market in 1987. Prozac was FDA approved on December 29, 1987. Its manufactured by Eli Lilly and Company.
Zoloft (Sertraline hydrochloride) was the next SSRI to come to market across the usa, also it was approved by way of the FDA on December 30, 1991. Zoloft is manufactured by Pfizer Inc.
Paxil (Paroxetine hydrochloride) was the third SSRI ahead to market in the United States and was approved because of the FDA on December 29, 1992. Paxil is manufactured by GlaxoSmithKline.
Luvox (Fluvoxamine maleate) was the 2nd SSRI FDA approved on December 05, 1994. However, today its marketing status is "Discontinued".
Celexa (Citalopram hydrobromide) was approved from the FDA on July 17, 1998. Celexa is manufactured by Forest Pharmaceuticals, Inc.
Lexapro (Escitalopram oxalate) will be the newest all of them selective of many SSRIs approved by way of the FDA on August 14, 2002. Lexapro is manufactured by Forest Pharmaceuticals, Inc. Lexapro is usually a cleaner, improved element of Celexa.
Mechanism of act
The health of the brain talks to itself through the use of special chemicals called neurotransmitters, for instance serotonin and norepinephrine. Neurotransmitters carry signals from one particular nerve cell to another. Low manner of serotonin and norepinephrine were never proven to cause depression however it widely considered that elevation of these chemicals is associated with improvement in mood in depressed people.
All SSRIs hold the same general mechanism of action. SSRIs appear to relieve symptoms of depression by blocking the reabsorption (reuptake) of serotonin by certain nerve cells within the brain. This leaves more serotonin available, which reinforces neurotransmission (sending of nerve impulses) and improves mood. After all, the appropriate amounts of natural serotonin will rise again, whereas in the some instances the SSRI may well be reduced and withdrawn.
Approved indications and applies
SSRIs have already been primarily utilised for managing depression and really have been studied for several indications outside of depression.
Celexa (Citalopram) is indicated for treatment of:
melancholy
Lexapro (Escitalopram) is indicated for your treatment of:
major a depressive disorder
generalized sadness (GAD)
Paxil (Paroxetine) is indicated for the remedy for:
major a depressive disorder
obsessive compulsive disorder (OCD)
panic disorder
social anxiety disorder (sad)
generalized sadness
posttraumatic stress disorder (PTSD)
Prozac (Fluoxetine) is indicated of the treatment of:
major a depressive disorder
obsessive-compulsive disorder
moderate to severe bulimia nervosa
panic disorder
in January 2003, Prozac was approved by the FDA for your remedy for depression and OCD in youngsters and adolescents that are 7 to 17 years of age.
Zoloft (Sertraline) is indicated for your treatment of:
major depressive disorder
obsessive-compulsive disorder
panic disorder
posttraumatic stress disorder
premenstrual dysphoric disorder (PMDD) in adults (newest indication)
sad (social anxiety disorder)
Value
Clinical trials comparing an SSRI with another SSRI indicate that drugs within this class are equally efficacious. Each SSRI produces approximately a 60% overall response rate (ie, not less than a 50% discount in symptoms as a result of treatment).
Adverse reactions & negative effects
While SSRIs do not arrive at will be found overall tolerability, the reported incidences of specific uncomfortable side effects vary. Negative effects that patients experience are usually mild to moderate and do not require dose reductions or discontinuation. SSRIs possess the following adverse reactions:
Nausea. The most coomon side effect accociated with utilization of SSRIs is nausea. Paroxetine and sertraline have already been associated with a little more cases of nausea.
Ed. Depression itself could create erectile dysfunction and all SSRIs seem to have been involved with erectile dysfunction during therapy in males and females. There could be lesser detrimental effect on sexual function by fluoxetine when compared to other agents. Citalopram has been involved with loss of libido. Paroxetine seems to cause the highest rate of impotence.
Anticholinergic effects. Paroxetine causes a higher rate of anticholinergic effects, such as lack of saliva, constipation, and cognitive disruption, in comparison to other SSRIs. These effects might be particularly problematic to tolerate for elderly or concomitantly medically ill patients.
Weight. The SSRIs vary inside their effect on the mass. Sertraline is generally linked to a compact magnitude of weightloss in the acute phase of treatment, whereas paroxetine can cause body weight after long-term treatment. Fluoxetine has got the most potent appetite-suppressing effects within the temporary and produces a greater degree of weightloss than paroxetine, sertraline, citalopram, or escitalopram.
Diarrhea. Sertraline and fluoxetine are definitely more frequently connected with diarrhea, paroxetine features a lower incidence.
Anxiety, agitation, insomnia. Fluoxetine is linked to highest rate of anxiety and agitation. Escitalopram and paroxatine are not as likely to cause insomnia than fluoxetine and sertraline.
Dry mouth. Citalopram and paroxetine are more likely to cause lack of saliva than escitalopram and fluoxetine.
Drowsiness, fatigue. Paroxetine continues to be associated with highest rate of drowsiness, somnolence than other SSRIs.
Headache. Sertraline and fluoxetine are linked to higher-level of headache.
Many times, antidepressants may be involved with worsening symptoms of depression or thoughts of suicide or behavior, particularly at the outset of treatment or once you change your dosage. Make sure you speak to your doctor about any changes in your symptoms. Yopu must have more careful monitoring at the start of treatment or with a change in treatment, otherwise you may need to stop klonopin if the symptoms worsen.
Pharmacokinetics
Some of the key differences among SSRIs result from differences throughout their pharmacokinetic properties. The only real pharmacokinetic parameters shared by all the SSRIs is the fact that they are relatively slowly, but completely, absorbed out of your gut. They differ with regard for their protein binding, metabolism, half-lives, whether or not they have linear or nonlinear pharmacokinetics, whether they have active metabolites.
Half-life
The half-life of any drug it s time forced achieve steady-state plasma concentrations (i.e., to metabolize half the dose and lower blood concentrations by 50%). Half-life may be used to estimate effort all it takes is clear a drug that came from the body after treatment is discontinued.
Fluoxetine is unique due to its long half-life as well as the long half-life from the active metabolite norfluoxetine. Fluoxetine consists of a half-life of 4-6 days and its active metabolite, norfluoxetine, uses a half-life of 4-16 days. In comparison, citalopram, escitalopram, paroxetine, and sertraline have shorter half-lives inside the range of 20-35 hours, and steady-state concentrations (and therapeutic effect) are reached a great deal more rapidly. The long half-life of fluoxetine may blunt the outcome of missed doses or treatment discontinuation and makes it much better to discontinue than any of the other SSRIs. Then again, fluoxetine requires a far longer washout period when compared to the other SSRIs (a couple weeks), particularly if switching to monoamine oxidase inhibitors (MAOIs) or TCA.
Antidepressants with relatively short half-lives are desirable if you have multiple comorbidities and luxurious, multiple-drug regimens since they be suitable for once-daily dosing. A quick half-life enables physicians to switch quicker and safely to an alternate antidepressant if treatment fails or if unfavorable drug reactions occur.
Linear and nonlinear pharmacokinetic.
Among the list of important differences to document on the list of SSRIs is if their pharmacokinetic properties are linear or nonlinear.
Citalopram, escitalopram and sertraline show linear and dose-proportional pharmacokinetics. Plasma concentrations of these drugs are proportional towards the daily dose administered and, therefore, predictable. In comparison, fluvoxamine, fluoxetine and paroxetine have nonlinear pharmacokinetics. Higher doses may produce much greater increases in plasma drug concentrations than would otherwise be expected. Thus, increasing the dose of paroxetine or fluoxetine may end up in disproportionate and unpredictable increases in plasma levels, half-lives, and uncomfortable side effects. Titration of fluoxetine and paroxetine doses may therefore being more difficult when compared with citalopram, escitalopram and sertraline.
Drug Activity
The interaction between monoamine oxidase inhibitors (MAOIs) and SSRIs is the most important drug interaction limiting SSRI use. This mix can lead into the development of a hyperserotonergic syndrome consisting of excitement, diaphoresis, rigidity, hyperthermia, tachycardia, hypertension, and possibly death. The severity in this interaction necessitates at least 5 week washout when switching an individual from fluoxetine to an MAOI o provide for complete elimination of your fluoxetine. At the very least 14 days ought to be allowed after stopping citalopram, escitalopram, paroxetine or sertraline before beginning an MAOI. This difference in washout time between fluoxetine and citalopram, escitalopram, paroxetine and sertraline when switching because of an SSRI to an MAOI is among the key differences between SSRIs.
Author Resource:-
Citalopram, escitalopram and sertraline side effects of Sertraline develop the lowest potential for drug interactions on the list of SSRIs. Citalopram should really be avoided in patients prone to take overdoses. Sertraline could be Nexium side effectspreferable for cardiac patients taking beta blockers or type IC antiarrhythmic agents.
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