Imipramine: uses and side effects of this antidepressant

The first tricyclic antidepressant in history was imipramine, which appeared in 1951. Although this and other tricyclics were the most widely used drugs to treat depression for many decades, little by little replaced other more effective drugs, although imipramine continues to be used in certain disorders, not just type depressant.

In this article we will analyze in detail the most important therapeutic uses and side effects of imipramine. We will also describe the key pharmacological properties of this drug and explain in which cases its use is contraindicated.

• Related article: "Types of psychoactive drugs: uses and side effects"

What is imipramine?

Imipramine is a antidepressant medication of the tricyclic class, to which clomipramine, amitriptyline, doxepin, nortriptyline or desipramine also belong. Imipramine was the first of these drugs to be developed; the initial purpose was its use as a sedative in cases of schizophrenia and as an antihistamine.

Tricyclic antidepressants were for a long time the pharmacological treatment of choice in cases of depression. However, at present they have been relegated to the background due to the emergence of

selective serotonin reuptake inhibitors (SSRIs) and other drugs with higher degrees of specificity and tolerability.

The effects of imipramine are very broad, so that it acts on different neurotransmitters; this explains both its therapeutic properties and the adverse reactions associated with its consumption. They are especially relevant agonist effects on serotonin and norepinephrine, which take place through the inhibition of its reuptake.

Although imipramine has been marketed under different generic names, the best known of all is "Tofranil" since this brand was the one that popularized the product and it continues to be sold in many countries today from today.

Therapeutic uses of this drug

Imipramine, like the other drugs in the tricyclic class, is primarily used to treat symptoms of the depression spectrum. Research suggests that it is especially useful in cases in which depression is associated with anxiety-like symptoms, particularly psychomotor agitation.

In this sense, imipramine is sometimes prescribed to people with disorders such as major depression, dysthymia (chronic, mild depression with marked anxiety), bipolar disorder, panic disorder, and agoraphobia. It has also been applied in cases of attention deficit hyperactivity disorder, better known by the abbreviation “ADHD”.

It is also relatively common to use imipramine in the nocturnal enuresis treatment. Its effectiveness in this disorder is due to the fact that this drug reduces the proportion of sleep phases of slow waves, and it is in these when the episodes of involuntary urination take place usually.

• You may be interested in: "Types of antidepressants: characteristics and effects"

Adverse reactions and side effects

Adverse reactions most commonly associated with imipramine treatment include drowsiness, feelings of dizziness, rapid heartbeat, dry mouth, urinary retention and orthostatic hypotension (sudden drop in blood pressure). Changes in brain electrical activity, such as those related to sleep, also occur.

Other signs that affect the central nervous system and that have a somewhat lower frequency are anxiety, agitation, insomnia, nightmares, headaches, confusion or the appearance of tremors, convulsions and other motor symptoms related mainly to the system extrapyramidal.

Imipramine also causes other physiological side effects. Among these we find cardiovascular alterations (hypertension, palpitations, dysrhythmias...), blurred vision, nausea, vomiting, increased appetite, gastrointestinal complaints (such as cramps), constipation, jaundice, and dilated pupils or mydriasis.

Overdose of imipramine or other tricyclic antidepressants causes blurred vision, mydriasis, confusion, drowsiness, and increased heart rate. The toxic dose is easier for children to reach, and sometimes death can result from cardiac arrest if the alterations are not resolved quickly.

Contraindications and precautions

Even compared to other tricyclic antidepressants, imipramine has a very strong pharmacological potency. Because of this and its interaction with receptors for multiple types of neurotransmitters, the use of imipramine should be avoided in many and varied circumstances.

This drug is contraindicated in people with a history of disorders such as alcoholism, hyperthyroidism, diabetes, glaucoma, kidney and liver problems, epilepsy and particularly disorders of the cardiac system.

The consumption of imipramine is also not recommended if drugs of different types are being taken simultaneously, including barbiturates, inhibitors of monoamine oxidase enzyme (MAOI), SSRIs, lithium, methylphenidate, anticholinergics, or buspirone, the drug of choice for anxiety disorder widespread.

Current use of imipramine it is discouraged to some extent due to its pharmacological profile, difficult to tolerate for many people and very non-specific in terms of its effects on relevant neurotransmitters. However, it must also be taken into account that SSRIs and other modern antidepressants also cause significant adverse reactions.