SSRI - Selective Serotonin Reuptake Inhibitor (Wiki)

Please note: Dosage equivalents are provided for certain drugs below and are denoted as unit equivalents, i.e. one unit of drug x is roughly the equivalent as one unit of drug y, where the dosage equal to one unit varies.

A relatively new type of antidepressant, this drug family rocketed into the public eye, fuelled by the phenomenally successful medication fluoxetine. They act selectively on the monoamine neurotransmitter serotonin, inhibiting its reuptake and therefore increasing the amount available to neurons to soak in, as the name suggests.

In theory, serotonin should be the most effective monoamine neurotransmitter to target as it is believed to metabolise stress hormones; indeed, SSRI antidepressants are effective in the treatment of anxiety based disorders. However, with the advent of the SSRE antidepressant tianeptine this particular theory has been called into doubt, as SSRE antidepressants tend to accelerate or enhance the reuptake of serotonin and at the same time exerts a notable antidepressant and anxiolytic effect, typically with less side effects.

Typically, these drugs cause less side effects than tricyclic antidepressants and are safer in the event of an overdose. They should not typically be taken in conjunction with RIMA or MAOI antidepressants and a "cooling out" period is suggested in order to minimise the chance of a potentially serious condition known as serotonin syndrome; however, combinations are not totally out of the question. Effective combinations with NARI, SNaDRI and SDRI antidepressants can typically be made without serious consequences.

"In the 1980s a new type of antidepressant called a serotonin reuptake inhibitor proved markedly successful. Called fluoxetine, it apparently achieves its therapeutic effect by interfering solely with the reabsorption of serotonin within the brain, thus allowing that neurotransmitter to accumulate there." - Encyclopædia Britannica

Alaproclate (Wiki)

Brand names: None known
Formula: C13H18ClNO2
Half life: ~ 3.25 hours
Single unit dose: Unknown
Recommended outpatient dose: Unknown
Maximum outpatient dose: Unknown

Alaprociate is an old, pre-1990s antidepressant that has fallen out of favour. At the time of writing, it is still used to aid in the withdrawal from illegal hard drugs, notably cocaine. It is currently being investigate as a treatment in other areas.

Citalopram (Nitalapram) (Wiki)

Brand names: Celexa®, Cipramil®
Formula: C20H22FN2O
Half life: ~ 35 hours
Single unit dose: 20mg per day
Recommended outpatient dose: 20mg per day [Verified]
Maximum outpatient dose: 60mg per day [Verified]
No. 5 most prescribed antidepressant, 2005

Generally regarded as a "safe" medication (meaning that it is less likely than average to cause unwanted side effects), citalopram is primarily indicated for the treatment of depressive affective disorders but is also used to treat anxiety related disorders (including panic disorders) and body dysmorphic disorder. The medication is also thought to be beneficial in the treatment of diabetic neuropathy, post-stroke pathological crying and premature ejaculation.

Main side effects associated with this drug include drowsiness, fatigue, tremor, headaches, dizziness, arrythma, changes in blood pressure, hyperhidrosis, sleep disturbances, a dry mouth and/or ejaculatory problems. Rarer side effects include confusion, convulsions, anxiety, significant mood changes and/or allergic reactions.

Diphenhydramine (Wiki)

Brand names: Benadryl®, Dimedrol®
Formula: C17H21NO
Half life: ~ 1 to 4 hours (vague figure)
Single unit dose: Unknown
Recommended outpatient dose: 50mg per day [Not Verified]
Maximum outpatient dose: 100mg per day [Highly Questionable]

Primarily a hypnotic, specifically an antihistamine.

This drug is available over the counter without the need for a prescription. Interestingly, it works as an SSRI medication, inhibiting the reuptake of the monoamine neurotransmitter serotonin in the brain and was the forerunner to the famous antidepressant fluoxetine.

Escitalopram (Wiki)

Brand names: Cipralex®, Emovit®, Lexapro®, Seroplex®, Sipralexa®, Vivalan®, Vivarint®, Vicilan®
Formula: C20H21N2FO
Half life: ~ 30 hours
Single unit dose: 5mg per day
Recommended outpatient dose: 10mg per day [Verified]
Maximum outpatient dose: 20mg per day [Verified]
No. 2 most prescribed antidepressant, 2005
No. 1 most prescribed antidepressant in USA, 2006

Escitalopram is a derivative of the drug citalopram, an antidepressant of the same family, whose main advantage over the parent drug is in tolerability. The drug entered patent as citalopram left its own, prompting cynicism and speculation that the drug company was in fact marketing a near identical drug at a higher price.

This drug is the most selective SSRI antidepressant available and has proven its worth in clinical trials; it still sports the typical side effects that SSRIs tend to have, including those in withdrawal.

Etoperidone (Wiki)

Brand names: None known
Formula: C19H28ClN5O
Half life: Unknown
Single unit dose: Unknown
Recommended outpatient dose: Unknown
Maximum outpatient dose: Unknown

I know very little of this medication. Structurally, it is similar to trazadone (an SSRI antidepressant) and shares many of the typical SSRI side effects. I do not believe that it is currently available for therapy, although in the 1970s it was used to counter the effects of the illegal drug LSD.

Fluoxetine (Wiki)

Brand names: Adofen®, Alzac 20®, Andep®, Ansilan®, Auroken®, Deprexin®, Deproxin®, Fluctin®, Fluctine®, Fludac®, Flufran®, Flunil®, Fluox®, Fluoxac®, Fluoxeren®, Fluoxil®, Fluox-Puren®, Fluronin®, Flusac®, Flutin®, Flutine®, Fluxen®, Fluxetil®, Fluxetin®, Fluxil®, Fontex®, Foxetin®, Lanclic®, Lorien®, Lovan®, Magrilan®, Margrilan®, Modipran®, Neupax®, Nopres®, Nuza®, Oxactin®, Oxedep®, Pragmaten®, Prizma®, Proctin®, Prodep®, Prozac®, Prozac 20®, Rowexetina®, Salipax®, Sanzur®, Symbyax® (when compounded with Olanzapine), U-Zet®, ZAC®, Zactin®, Zepax®, Флуоксетин®
Formula: C17H18F3NOHCl
Half life: ~ 4 to 6 days
Single unit dose: 20mg per day
Recommended outpatient dose: 20mg per day [Verified]
Maximum outpatient dose: 80mg per day [Verified]
No. 3 most prescribed antidepressant, 2005

Fluoxetine is also known and classified as a bicyclic antidepressant, meaning that the chemical structure of the drug consists of two rings.

This drug started out life as an antihistamine, diphenhydramine, which was found to inhibit the reuptake of the monoamine neurotransmitter serotonin. Fluoxetine is fairly stimulating, yet is an approved treatment for anxiety related conditions; even more converse is the fact that anxiety is one of the most (if not the most) frequent side effect of fluoxetine therapy. The drug also possesses a remarkably long half life which has proven useful in the treatment of more reluctant patients; should they suddenly stop taking the drug, the antidepressant effect will remain for a fair amount of time, hopefully long enough for the cessation to be noticed and rectified. Currently fluoxetine is available for use in children as young as eight, should psychotherapies fail.

Fluoxetine fast became an infamous drug under the brand name of Prozac; millions were prescribed the drug, largely due to an extremely effective and extensive advertising campaign. Unfortunately, the medication became controversial towards the end of the century due to an increased risk of suicidal behaviour amongst patients treated with the drug.

The most common side effects are anxiety, headaches, nervousness, insomnia, fatigue, tremor, dizziness, dry mouth, weight loss (possibly leading to anorexia), excessive sweating, nausea and diarrhea; fluoxetine also causes mania in approximately 6% of patients. Maximum therapeutic effect usually manifests after a period of a month to a month and a half.

Fluvoxamine (Wiki)

Brand names: Dumirox®, Dumyrox®, Faverin®, Favoxil®, Fevarin®, Floxyfral®, Fluvohexal®, Fluvoxin®, Luvox®, Voxamin®
Formula: C15H21F2N2O2
Half life: ~ 15.6 hours
Single unit dose: 50mg per day
Recommended outpatient dose: 100mg per day [Verified]
Maximum outpatient dose: 300mg per day [Verified]

Although its therapeutic effects are similar to the average SSRI antidepressant, fluvoxamine has a somewhat different side effects profile to other medication in the same family; in particular, it has a comparatively light effect on the patients libido and instead of causing weight gain, it causes weight loss. It sports a 4% chance of inducing mania in patients compared with fluoxetines 6%.

Unfortunately, this drug has fallen out of favour - one of the two teenaged shooters involved in the Columbine High School tragedy was shown to be taking fluvoxamine at the time, so naturally the press indicated that the drug was at fault. As a result, the drug became difficult to successfully market, leading to the discontinuation of the medication in certain areas of the world. Where it remains it often bears the following warning or one similar to it: "Taking antidepressants may increase suicidal thoughts and actions in about 1 out of 50 people 18 years or younger."

Paroxetine (Wiki)

Brand names: Aropax®, Cebrilin®, Deroxat®, Paroxat®, Paroxet®, Paxan®, Paxetin®, Paxil®, Paxtine®, פאקסט®, Serorat®, Seroxat®, Paroxat®, Pondera®, XET®, パキシル/®, Паксил®
Formula: C19H20FNO3Cl0.5H2O
Half life: ~ 24 hours
Single unit dose: 20mg per day
Recommended outpatient dose: 20mg per day [Verified]
Maximum outpatient dose: 50mg per day [Verified]
No. 6 most prescribed antidepressant, 2005
No. 6 most prescribed antidepressant in USA, 2006

One of the more popular antidepressants, paroxetine is mainly indicated for the treatment of depressive disorders but has proven effective in the treatment of anxiety related disorders. It was the first medication to be approved for the treatment of social anxiety disorder within the USA, earning it the label of the "anti-shyness drug".

Paroxetine is also proving itself useful in the treatment of premature ejaculation, chronic headache and diabetic neuropathy; it is also being studied as a treatment for compulsive gambling and hot flashes.

The most potent SSRI antidepressant, this drug unfortunately has a fairly prominent side effects profile. In late 2005, Australia issued a dire warning about the drugs impact on unborn babies, pointing out that taking the drug could double the chances of cardiovascular defects in unborn children and that in general the chances of defects was raised by approximately 60% on average.

Sertraline (Wiki)

Brand names: Altruline®, Apo-Sertral®, Aremis®, Asentra®, Atruline®, Besitran®, Concorz®, Dominum®, Fatral®, Gladem®, Lesefer®, Lustral®, Nudep®, Serlain®, Serlift®, Sertralin®, Sertranex®, Sertranquil®, Sosser®, Stimuloton®, Xydep®, Zolof®, Zoloft®, Zosert®
Formula: C17H17NCl2
Half life: ~ 26 hours
Single unit dose: 50mg per day
Recommended outpatient dose: 50mg per day [Verified]
Maximum outpatient dose: 200mg per day [Verified]
No. 1 most prescribed antidepressant, 2005
No. 2 most prescribed antidepressant in USA, 2006

Often regarded as the competitor to citaloprams "safest SSRI" mantle, sertraline is in fact an SSDRI (Selective Serotonin and Dopamine Reuptake Inhibitor) antidepressant but is primarily viewed as an SSRI as the effect on the monoamine neurotransmitter dopamine is comparitively minor. It was first approved for use in 1991.

Being a sedative drug, sertraline is particularly useful in anxiety related disorders and in patients who are having trouble sleeping. It is approved for use as a treatment for depressive disorders, obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), panic disorders and social phobias/anxiety disorders. It is also proving useful in the treatment of aggressive behaviour linked to personality disorders.

In terms of side effects, sertraline is fairly neutral. It causes drowsiness and sedation and can also lead to weight loss, usually a desirable effect. It can induce mania, but this only happens in 0.5% of cases (compared to the 6% under fluoxetine care). It is seen as the best option for nursing mothers as it is pretty safe and retains its effectiveness.

Trazodone (Wiki)

Brand names: Azonz®, Beneficat®, Bimaran®, Deprax®, Depresil®, Depyrel®, Desirel®, Desyrel®, Mesyrel®, Manegan®, Molipaxin®, Pragmarel®, Sideril®, Reslin®, Taxagon®, Thombran®, Trazalon®, Trazolan®, Trazone®, Trazonil®, Trittico®
Formula: C19H22ClN5O
Half life: ~ 4.4 hours
Single unit dose: Unknown
Recommended outpatient dose: 150mg per day [Verified]
Maximum outpatient dose: 600mg per day [Verified]

Although trazodone does selectively inhibit the reuptake of the monoamine neurotransmitter serotonin, it is not typically regarded as an SSRI as it is believed that its antidepressant effect is caused by another mode of action. However, in terms of side effects it is fairly similar to SSRI antidepressants in general; in particular, it sports the usual discontinuation syndrome.

Seemingly a wonderdrug, trazodone is a sedative antidepressant that has proven useful in the treatment of anxiety related disorders. Seemingly, this drug starts to take hold within the first week of therapy, three to four times faster than typical antidepressants. The drug also has a far smaller side effects profile than typical antidepressants in virtually all facets (sexual problems, anticholinergic and adrenolytic side effects, amongst others). Curiously, it does interact with some foodstuffs, most notably grapefruit juice - whilst one glass is unlikely to have any effect whatsoever, large amounts are discouraged. The most common side effects include the said sedation, nausea and/or vomiting, headaches and a dry mouth.

Trazodone is, as was previously mentioned, a sedative drug; as such it is useful as a treatment for insomnia and fibromyalgia, either in the short term or the long term.

Zimeldine (Wiki)

Brand names: Normud®, Zelmid®
Formula: C16H17BrN2
Half life: ~ 8.4 hours
Single unit dose: Unknown
Recommended outpatient dose: 200mg per day [Not Verified]
Maximum outpatient dose: 400mg per day [Not Verified]

Zimeldine was the first established SSRI antidepressant, first marketed in the early 1980s. Unfortunately, due to a potentially fatal side effect (central and/or peripheral neuropathy known as Guillian-Barré syndrome) and due to multiple hypersensitivities involving vital organs the drug has been banned worldwide. It also seemingly caused an increase in suicidal behaviour in patients, although this is not an accusation unique to zimelidine. It has been superseded by fluvoxamine and, later, by fluoxetine.

It was found to be effective in the treatment of cataplexy, a feature typically found in tricyclic antidepressants.