Treatment of neuropathic pain

Currently, treatment of neuropathic pain involves the use of:

• antidepressants,
• anticonvulsants,
• tramadol,
• opioids,
• local anesthetics.

European guidelines for the treatment of neuropathic pain

Problem status

• Neuropathic pain is widespread in the population
• Neuropathic pain often reaches a high degree of intensity
• Neuropathic pain is often associated with comorbid disorders (depression, anxiety, sleep disorders), high disability, decreased quality of life, and decreased ability to work

Neuropathic pain is poorly diagnosed and treated in therapeutic practice.

Medical tactics

• Listen carefully to the patient (words that describe neuropathic pain);
• Assess the type of pain (neuropathic, nociceptive, combined, neither);
• Diagnosis of the disease that led to the occurrence of neuropathic pain and its treatment, if possible;
• Development of a treatment strategy aimed at reducing pain, increasing the patient’s functional abilities, and improving the quality of life;
• Treatment should begin as early as possible and be carried out actively.

Diagnosis of neuropathic pain

Use of screening methods to identify signs of possible neuropathic pain. Criteria for neuropathic pain:

• The localization of pain corresponds to the anatomical zones of innervation;
• During clinical examination, sensory disturbances (to touch, needle prick, heat, cold stimuli) are revealed;
• The cause of neuropathic pain has been established (using clinical or instrumental methods).

Pharmacotherapy is the main treatment for neuropathic pain.

The principles of pharmacotherapy are:

• Determination of the drug for treatment and its prescription;
• Informing the patient about the disease, treatment tactics, possible adverse events, duration of treatment;
• Monitoring patient compliance with doctor's orders. 50

Painful polyneuropathy (painful polyneuropathy after chemotherapy and HIV polyneuropathy are excluded)

• Evidence of efficacy: tricyclic antidepressants (TCAs), duloxetine, venlafaxine, pregabalin, gabapentin, opioids, tramadol (level A);
• NNT*: TCAs = 2.1-2.5, venlafaxine = 4.6, duloxetine = 5.2, rpentine = 3.9, opioids = 2.6, tramadol = 3.4; I
• not indicated: capsaicin preparations, mexiletine, oxcarbazeprine, SSRIs, topiramate (level A), memantine, mianserin, topical clonidine level B); inconclusive/conflicting results: carbamarin, valproate, SSRIs.

Recommendations:

• TCAs, pregabalin, gabapentin (first-line drugs);
• IOZN - second-line drugs (in the absence of risk of cardiac complications);
• Tramadol or strong opioids are third-line drugs
• NNT - Number Needed to Treat. An indicator representing the ratio of the number of patients in the study to the number of patients with 50% or more reduction in pain intensity. The lower the NNT ratio, the more effective the treatment.

Postherpetic neuralgia

• The efficacy of TCAs, pregabalin, gabapentin, opioids has been proven (level A);
• Probably effective: topical lidocaine, tramadol, valproate, topical capsaicin (level B);
• NNT: TCAs = 2.6, pregabalin = 4.9, gabapentin = 4.4, opioids = 2.7, tramadol = 4.8, valproate = 2.1;
• Not recommended: NMDA antagonists, mesiletine, lorazepam (level A).

Recommendations:

• TCA, pregabalin, gabapentin are first-line drugs;
• Lidocaine locally (especially in the elderly and in the presence of allodynia);
• Strong opioids are second-line drugs.

Trigeminal neuralgia

Carbamazepine has been shown to be effective (Level A), NNT = 1.8; Oxcarbazepine is probably effective (Level B);

• Other drugs (baclofen, lamotrigine) can be prescribed only if carbamazepine or oxcarbazepine are ineffective or surgical treatment is undesirable,
• Not recommended: eye drops containing anesthetics (level A).

Recommendations:

• Carbamazepine 200-1200 mg per day or Oxcarbazepine 600-1800 mg per day;
• In drug-refractory cases - surgical treatment.

Central neuropathic pain

Central post-stroke pain, pain after spinal injury:

• Probably effective: pregabalin, lamotrigine, gabapentin. TCAs (level B)
• Not recommended: valproate, mexiletine (level B).

Neuropathic pain in multiple sclerosis:

• Cannabinoids (Level A) are recommended only when other medications have been ineffective.
• Pregabalin - for central pain:
• Cannabinoids for Multiple Sclerosis Pain.
• Radicular back pain: no randomized clinical trials;
• Postoperative/posttraumatic neuropathic pain: very few studies;
• Complex regional pain syndrome type 2: no randomized clinical trials.
• Neuropathic pain in infiltrative tumor: gabapentin or amitriptyline in addition to opioids,
• Post-traumatic/post-operative neuropathic pain: amitriptyline or venlafaxine;
• Phantom pain: gabapentin or morphine (?);
• Guillain-Barre syndrome: gabapentin.

Evaluation of treatment effectiveness

1. Clinical significance is a reduction in pain of more than 30%;
2. Reduction of phenomena accompanying neuropathic pain (patient survey, assessment of allodynia during repeat visits);
3. Improved sleep and mood;
4. Improving functions (when interviewing the patient, it is clarified what he can do, the patient’s behavior and actions during the doctor’s appointment are assessed);
5. Improving the quality of life;
6. Possible side effects.

Item 1,2,3,4,5 - item 6 = general satisfaction. If drug treatment is ineffective, neurostimulation is indicated.