Butriptyline: characteristics, uses and side effects

Antidepressant drugs include a series of medications used to treat depressive symptoms and behavioral alterations associated with low mood. Within the category of antidepressants is the group of tricyclics, among which are butriptyline, a medication that differs from the rest of tricyclics due to its peculiar mechanism of action.

In this article we explain what butriptyline is and what tricyclic antidepressants consist of, what is the mechanism of action of this drug, what type of side effects it causes, and what is its clinical effectiveness, compared to other medications Similar.

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What is butriptyline?

Butriptyline is a drug from the group of tricyclic antidepressants, chemically related to amitriptyline and imipramine. It is a medication that has been used in various European countries, including Spain, in the treatment of depression. Because it has a somewhat different pharmacological action than other tricyclic antidepressants, it has been described as an “atypical” or “second generation” drug.

Since its development in 1974 by Wyeth (formerly known as American Home Products), one of the largest pharmaceutical companies in the world. world, and its subsequent marketing in the United Kingdom, it was dispensed very rarely compared to other antidepressant drugs of the same cluster. It was marketed under the brand names Evadene, Evasidol, Evadyne and Centrolese.

Although butriptyline has been considered an antidepressant drug from the group of tricyclics, their mechanism of action differs significantly from prototypical tricyclics such as imipramine or amitriptyline. Next, let's see what the mechanism of action of tricyclic antidepressants is, in order to compare them with that of butriptyline.

Tricyclic antidepressants

Tricyclic antidepressant medications are used in the treatment of depressive disorders and other behavioral pathologies, as is butriptyline. These types of drugs act as monoamine agonists.. Its main effects occur on serotonin receptors, norepinephrine receptors and, to a lesser extent, dopaminergic receptors.

The therapeutic activity of tricyclic antidepressants is produced by the inhibition of the reuptake of these neurotransmitters, which leads to an increase in the availability of these monoamines in the cleft synaptic. However, these medications also act, although secondarily, on histamine and cholinergic receptors (related to acetylcholine), exerting an antagonistic effect on them.

The mechanism of action of tricyclics is not very specific, since Its therapeutic targets go beyond the most relevant neurotransmitter receptors, and affect another series of receptors.; This means that although they may be effective in relieving depressive symptoms, they can also cause serious side effects and adverse reactions.

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Mechanism of action

In in vitro studies, butriptyline has been shown to be a potent antihistamine and anticholinergic drug, with moderate antagonistic effects. on the serotonergic 5-HT2 receptor and the α1 adrenergic receptor, and with a very weak or insignificant action as an inhibitor of reuptake of norepinephrine.

This mechanism of action seems to give this medication a profile very similar to that of the drugs iprindole and trimipramine, whose Antagonistic effects on serotonin receptors could be responsible for its effectiveness in improving mood.

However, in several clinical trials using similar doses, butriptyline has been found to be equally effective as amitriptyline and imipramine in treating depressive symptoms, despite the fact that these two antidepressant drugs have a more potent effect as 5-HT2 antagonists and as serotonin-norepinephrine reuptake inhibitors.

It has been suggested that the mechanism of action of butriptyline is different from that of other tricyclic antidepressants and that it may work as a prodrug, converting to an active metabolite once it is introduced into the body, thus acting with a pharmacodynamics different.

Side effects

Butriptyline, as we have mentioned, It is closely linked to amitriptyline and has side effects similar to this tricyclic antidepressant.. However, it seems that in the case of butriptyline, the sedation caused by its consumption is lower, compared to other tricyclics, as well as the risk of interactions with other medicines.

Since this drug has relatively weak effects as an α1 antagonist and practically non-existent effects as norepinephrine reuptake inhibitor, has almost none of the antiadrenergic side effects and adrenergic.

Definitely, The most notable side effects and adverse reactions of butriptyline are related to the potent antihistamine and anticholinergic effects. that produces. Below are the most common ones:

• Sedation (less than that of other tricyclic antidepressants, as we have mentioned)
• Drowsiness.
• Dry mouth.
• Constipation.
• Urinary retention.
• Blurry vision.
• Cognitive/memory impairment

Clinical efficacy

To evaluate the effectiveness of a drug, it is usually compared with another from the same group and under appropriate experimental conditions. In this sense, in a multicenter study in which two experimental groups and another control group were randomly assigned, under double-challenge conditions. Blinded, the efficacy of butriptyline was compared to amitriptyline in a group of 77 patients between 18 and 70 years old and diagnosed with depression. primary.

Butriptyline and amitriptyline were administered on an identical increasing schedule, up to 150 mg daily in the first week and a flexible schedule during the last 3 weeks of the trial. The mean daily doses were 145 mg butriptyline and 142 mg amitriptyline after 2 weeks; and 77.5 mg of amitriptyline and butriptyline, after 4 weeks. Nitrazepam (a hypnotic anxiolytic drug) and haloperidol (a conventional antipsychotic drug) were also allowed (if necessary).

The symptomatology and antidepressant efficacy of the drugs were evaluated using the following tests: the Hamilton Depression Rating Scale, the general depression, the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression Scale (CGI), as well as a checklist of effects secondary.

After the initial comparison of the two treatment groups, the results showed that antidepressant effects were significantly better with butriptyline with respect to the number of withdrawals, in the total score and in the following factors of the General Depression Scale: depression, guilt, anxiety, somatization and somatic complaints. Furthermore, the frequency of haloperidol prescription was significantly lower in patients who were treated with butriptyline compared to those who used amitriptyline.

The general frequency of side effects and other parameters (hematological and biochemical variables, electrocardiogram, etc.) were the same in both groups. In conclusion, it was observed that butriptyline It has the same indications as amitriptyline, but shows better antidepressant efficacy at the same dose, as well as greater relief from anxiety, somatization and somatic complaints.

Bibliographic references:

• Brezinova, V., Borrow, S., Oswald, I., Robinson, D. Effect of butriptyline on subjective feelings and sleep (in English). Br J Clin Pharmacol. 1977 April; 4(2): 243–245. PMCID: PMC1429024. Last accessed June 11, 2008.
• Guelfi, J.D., Dreyfus, J.F., Delcros, M, Pichot, P. A double-blind controlled multicenter trial comparing butriptyline with amitriptyline (in English). Neuropsychobiology. 1983;9(2-3):142-6. PMID 6353270
• Kapadia, A. P., & Smith, S. M. (1976). A multi-center general practitioner assessment of butriptyline hydrochloride ('Evadyne'). Current medical research and opinion, 4(4), 278-284.