1. Introduction:  Fluoxetine is still a drug of choice in depression.

Fluoxetine is a new generation antidepressant, classified within the Selective Serotonin Reuptake Inhibitors or SSRIs. It was the first marketed drug of this group in 1987, when its sales reached a record number worldwide after appearing for the first time under the name of Prozac. Other brands such as Adofen, Astrin, Lecimar, Luramon, Nodepre and Reneuron later appeared.

Despite the time that has elapsed, it is still a very effective drug and from my perspective it is among the 5 antidepressants of first choice for the treatment of major depression. As it has been known for more than 30 years, it enjoys wide security and this is supported by a multitude of studies carried out since its massive prescription began in the general population. In fact, to date there are no studies that indicate the existence of serious adverse effects in its continued use over long periods of time, although we do have evidence of a certain loss of effect when it is administered for years. Nor is there much evidence in various meta-analyses that the suspension of fluoxetine in very prolonged treatments carries a greater associated risk of relapse.

2) Indications and form of administration.

Fluoxetine owes its brain action to its potent ability to inhibit serotonin reuptake. Its indications, officially approved by the FDA (Food and Drug Administration; North American drug agency), are depression, bulimia nervosa and obsessive-compulsive disorder. Due to its high efficacy, is also used regularly in chronic fatigue, fibromyalgia, premature ejaculation, substance dependence, social phobia, impulsive or aggressive behavior, borderline personality disorder, emotional instability, premenstrual dysphoria, chronic headache, paraphilias , dysmorphic disorder and post-traumatic stress.

Common treatment begins with a dose of 20 milligrams daily in the morning, although in case of ineffectiveness, it can be increased up to a maximum of 60 mg per day. The effects are not immediate and are achieved gradually over a period of one or two months, so at the beginning of treatment the concomitant use of benzodiazepines is useful to control anxiety or insomnia, common symptoms in depression. Being a stimulant drug, nervousness or even sedation may appear at the beginning of treatment and for this reason it is advisable to increase the dose slowly. In the case of long-term treatments, withdrawal of the drug can cause a rebound effect, so it should not be stopped suddenly.

3) Side effects.

Adverse reactions are infrequent and it is generally a well-tolerated drug. The most common appear during the first week of its administration and can be nausea, insomnia, headache, nervousness, drowsiness, anorexia, diarrhea, dry mouth, tremor, dizziness and sweating, orgasm disturbance in women and delayed ejaculation in men.

Cases of poisoning are extraordinarily rare. In case of severe poisoning, vomiting should be induced or gastric lavage performed under hospital control with special attention to respiratory and cardiovascular functions.

Like the rest of antidepressants, its use is advisable with great caution in patients who drive or operate heavy machinery, its concomitant use with alcohol or drugs being inadvisable. It should be withdrawn in lactating or pregnant women, since its complete safety in these circumstances has not been established.

4) Fluoxetine, from a clinical point of view.

The discovery of Fluoxetine dates back to the 1980s, when its introduction into psychiatry meant a true revolution in the approach to depression, leading the way in biological psychiatry. From that moment to the present day, Fluoxetine has been and still is the reference antidepressant to beat, despite the enormous number of new molecules that have been synthesized so far.

From an eminently clinical point of view, despite the enormous offer of new antidepressants that compete with it, it continues to be one of the main choices in the treatment of depression. Its combination of safety, high efficacy, good tolerance and very low cost justify the generalization of its use, even ahead of the novelties that are introduced annually in the antidepressant market. The only perhaps worrying point about this molecule is that it has been speculated that it could increase the level of irritability in some isolated patients and therefore be responsible for an increased risk of suicide, particularly in children and adolescents. My perception is that although there are isolated cases of irritability that are difficult to attribute to the drug, because depressive pathology sometimes presents with irritability, we have not found any casuistry that corroborates this statement and we have not observed this circumstance in our clinical practice. Therefore, it continues to be one of the best antidepressant drugs known to date.

Lastly, it is necessary to emphasize that our view of the drug is largely the result of accumulated clinical experience and therefore, is not exempt from subjectivity. Consequently, this guide is intended to fulfill a merely indicative function, particularly for the use of the drug by non-medical healthcare providers and patients.

Dr Ponce, psychiatrist