Date: {{$ActivityAssignDate}}

Dear Dr. {{ $doctorName }},

Subject: A survey to understand usage pattern of FDC Pregabalin & Nortriptyline for the treatment of neuropathic pain in India

The International Association for the Study of Pain (IASP) defines neuropathic pain as pain caused by a lesion or disease of the somatosensory nervous system. This definition replaces an older definition according to which neuropathic pain was “pain initiated or caused by a primary lesion, dysfunction, or transitory perturbation of the peripheral or central nervous system”.

Two changes are important in this change of definition: dysfunction and the neuronal lesion.

1. In the new definition of neuropathic pain, dysfunction is no longer accepted as a criterion because it is difficult to accept symptoms and soft signs as criteria if they cannot be verified objectively.


2. It is now specified that the lesion needs to affect the somatosensory system meaning that lesions or diseases outside the somatosensory pathways, e.g., the cerebellum, does not qualify as neuropathic.

Neuropathic pain is a chronic condition which represents a significant burden for patients, society and healthcare systems. The prevalence of neuropathic pain in the general population has been estimated at 6.9–10.0%.

Management includes effective pharmacotherapy options for patients with low back neuropathic pain like serotonin-norepinephrine reuptake inhibitors (duloxetine, venlafaxine), tricyclic antidepressants (amitriptyline, desipramine, nortriptyline), and gabapentinoid antiseizure medications (pregabalin, gabapentin). All have been shown to be more effective than placebo in randomized trials, and limited comparative data suggest that efficacy is similar across agents

Pregabalin binds with high affinity to the alpha2-delta site (an auxiliary subunit of voltage-gated calcium channels) in central nervous system tissues. TCAs can be further classified into tertiary amines (amitriptyline and imipramine) and secondary amines (nortriptyline and desipramine). These drugs block the reuptake of serotonin and norepinephrine thereby increase the availability of these inhibitory neurotransmitters in the descending pain pathway which assists in reducing the neuropathic pain. The secondary amines like nortriptyline are better tolerated than tertiary amines in terms of sedation and other side effects.

This survey is conducted to understand usage pattern of FDC Pregabalin & Nortriptyline for the treatment of neuropathic pain in India.

As you will be spending some extra time to give your feedback on the questionnaire based on your clinical experience, we offer to pay you by cheque a professional fee of Rs {{$contractAmount}}, on receiving the completed Survey Questionnaire Form from you.

We trust you and we are partners in promoting safe and effective drug therapy. In that spirit we hope you will consent to participate in this study. If you do, please sign and return the enclosed reply along with your visiting card for accuracy of records.