Treatment of depression and anxiety with back pain

According to the primary request for medical care, up to 80% of patients suffering from depression present complaints of a purely somatic nature, for example, headache, abdominal pain, muscular pains in the back, joints, and neck. The question arises as to why such common somatic manifestations in depression have not been adequately reflected in the guidelines for the diagnosis of this disease, although in many cases they can be the only signs of having a depressive disorder?

One possible reason for this is that such complaints are usually attributed to a physical illness, especially in therapeutic practice. In the event that complaints are limited to increased fatigue, loss of strength and morbid somatic manifestations, and clear affective and vegetative symptoms are absent, many physicians are prone to often exhausting search for somatic pathology. In turn, suspicion of the presence of a depressive or anxiety disorder in a patient arises usually on the condition that his complaints are primarily psychological or emotional. Another common mistake is related to the fact that as a goal in the therapy of patients suffering from depression, a simple improvement of the condition is chosen, and not a remission. Currently, the recommended standard for helping patients with depression is to completely eliminate all the symptoms: not only emotional, vegetative, but also painful somatic manifestations of this disease.

Read also: 8 things you need to know about antidepressants

Antidepressants are the most rapidly developing group of psychotropic drugs. It is enough to give some figures. So, over the past 15 years, 11 innovative antidepressants have been registered, including venlafaxine and duloxetine over the past two years.

Currently, not less than 10 different classes of antidepressants based on the monoamine theory have been isolated. They are grouped according to their chemical structure - tricyclic antidepressants (amitriptyline, melipramine, clomipramine, etc.), a specific or selective mechanism of action - MAOI inhibitors, reversible MAO inhibitors type A (moclobemide, pyrlinodol), selective inhibitors of the inverse seizure of serotonin (fluvoxamine, fluoxetine, paroxetine, sertraline, citalopram, escitalopram), selective norepinephrine reuptake inhibitors (reboxetine), selective serotonin reuptake stimulants (tianeptine), ngibitory reuptake of norepinephrine and serotonin (venlafaxine, duloxetine), norepinephrine reuptake inhibitors and dopamine (bupropion), noradrenergic and specific serotonergic (mirtazapine) and antagonists and serotonin reuptake inhibitors (nefazodone).

Numerous studies have shown that dual-acting antidepressants (selective serotonin and norepinephrine reuptake inhibitors) used to treat depression can also be effective in the treatment of chronic pain, double-acting drugs such as tricyclic antidepressants (amitriptyline, clomipramine) and venlafaxine, or a combination of antidepressants with serotonergic and noradrenergic effect, demonstrated greater efficacy of treatment compared with antidepressants acting preferably one neurotransmitter system.

Double effect (serotoninergic and noradrenergic) causes a more pronounced effect in the treatment of chronic pain. Both serotonin and norepinephrine participate in the control of pain through the descending pathways of pain sensitivity (ANCS). This explains the advantage of antidepressants with a double action for the treatment of chronic pain. The exact mechanism of action by which antidepressants cause an analgesic effect remains unknown. However, antidepressants with a dual mechanism of action have a longer analgesic effect than antidepressants, which affect only one of the monoaminergic systems.

Tricyclic antidepressants (amitriptyline) and norepinephrine and serotonin reuptake inhibitors (venlafaxine, duloxetine) showed the greatest efficacy in treating patients with chronic pain, and their analgesic effect is not directly associated with their antidepressant properties.

The greatest preference for the treatment of pain syndromes is given to amitriptyline. However, it has a significant amount of contraindications. The main mechanism of action of tricyclic antidepressants is to block the re-uptake of norepinephrine and serotonin, which increases their number in the synaptic cleft and enhances the effect on postsynaptic receptors. In addition, amitriptyline is able to block the sodium channels of peripheral nerve fibers and neuronal membranes, which can suppress ectopic generation of impulses and reduce neuronal excitability. The side effect of tricyclic antidepressants is due to blockade of beta-adrenergic, antihistamine (HI) and acetylcholine receptors, which significantly limits their use, especially in elderly patients.

They also have undesirable interactions with opioid analgesics, MAO inhibitors, anticoagulants, antiarrhythmics, etc.). It has been shown that amitriptyline is highly effective in acute and chronic neuropathic pain syndromes, as well as chronic back pain, fibromyalgia. The effective dose of the drug for the treatment of pain may be lower than the dose used to treat depression.

Venlafaxine has recently been widely used to treat pain syndromes, both associated with depression and without it. Venlafaxine in small doses inhibits the reuptake of serotonin, and higher - noradrenaline. The primary analgesic mechanism of venlafaxine is due to its interaction with alpha2 and beta2 adrenoceptors. Modulating the activity of the antinociceptive system (seam nucleus, peri-acveductal gray matter, blue spot). To date, convincing evidence has been accumulated of the high clinical efficacy of venlafaxine in the treatment of a variety of pain syndromes. Clinical studies indicate that venlafaxine is a good treatment for patients with chronic pain syndromes within a large depressive or generalized anxiety disorder. This is important, since more than 40% of patients with major depressive disorder have at least one pain symptom (headache, back pain, joint pain, pain in the extremities or pain in the gastrointestinal tract). The use of venlafaxine allows to lower both the level of depression and the severity of pain manifestations. Venlafaxin-XR is prescribed for major depressive, generalized anxiety and social anxiety disorders in doses from 75 to 225 mg / day. For some patients, low doses of venlafaxine may be effective. Treatment can begin with 37.5 mg / day with a gradual increase in the dose for 4-7 days to 75 mg / day.

Studies have shown that the analgesic effect of venlafaxine is due to mechanisms not associated with depression. Therefore, venlafaxine proved effective in pain syndromes not associated with depression and anxiety. Although indications of the appointment of venlafaxine for chronic pain are not yet included in the instruction for its use, the available data indicate that in most pain syndromes, a dose of 75-225 mg / day is effective. Data from randomized, controlled trials showed that pain relief occurs 1-2 weeks later. After the beginning of treatment. Some patients require a 6-week course of treatment to achieve a good analgesic effect of venlafaxine.