MEDICAL MANAGEMENT OF

NEUROPATHIC PAINDR SUDHIR KUMAR MD DM

SENIOR CONSULTANT NEUROLOGIST

APOLLO HOSPITALS, HYDERABAD

CL INICAL FEATUR ES OF NEUR OPATHIC PA IN

Pricking, tingling, pins and needles,

Electric shock or shooting pain,

Hot or burning sensation,

Numbness,

Pain evoked by light touching,

Painful cold or freezing pain

CAUSES OF NEUROPATHIC PAIN

Central Neuropathic Pain

Stroke,

Multiple sclerosis,

Spinal cord injury.

PERIPHERAL NEUROPATHIC PAIN

Diabetic peripheral neuropathy,

Post herpetic neuralgia,

Trigeminal neuralgia,

Nutritional deficiency,

Vasculitis and immune-mediated

Chemotherapy or drug induced

Cancer-related

Toxin-induced

MEDICAL TREATMENT

Pregabalin

Gabapentin

Dothiepin

Amitriptyline

Carbamazepine/oxcarbazepine

Duloxetine

Venlafaxine

Botox

Topical agents

PREGABALIN

Useful for most types of neuropathic pain,

Also reduces anxiety, improves sleep and controls epilepsy,

Dose ranges from 75 mg to 600 mg per day,

Start low, and gradually escalate the dose,

Common side effects are drowsiness, dizziness, weight gain, peripheral edema and worsening of depression.

GABAPENTIN

Effective for most types of neuropathic pain,

Starting dose 100-300 mg HSOD to TID,

Can be gradually titrated to a maximum dose of 3600 mg per day

Common side effects- sedation, dizziness, edema, weight gain; increased risk of falls and worsening of cognition (in elderly)

Gabapentin-Nortriptyline combination is more effective than gabapentin or nortriptyline alone.

CARBAMAZEPINE/OXCARBAZEPINE

Carbamazepine has been approved for use in trigeminal neuralgia (TN)

Initial dose is 200 mg twice daily, can be given upto a maximum dose of 1200 mg per day in 3 divided doses

Oxcarbazepine is also used for TN.

Side effects include drowsiness, dizziness, skin rash and hyponatremia (more common with oxcarbazepine)

TRICYCLIC ANTIDEPRESSANTS (1 )

Amitriptyline, nortriptyline and imipramine

Effective in diabetic neuropathy, PHN, traumatic nerve injury and post-stroke pain,

Starting dose 10-25 mg at bed time, can be gradually increased to a maximum of 150 mg at bedtime.

Helps in improving sleep and depression

Inexpensive and once daily dosing are plus points

Common side effects- dry mouth, urinary retention, sedation, constipation, decreased seizure threshold and cardiac toxicity.

DOSULEPIN (DOTHIEPIN)

Prothiaden has been used for long and is effective in several conditions causing neuropathic pain,

Safer than amitriptyline, lesser cardiac toxicity, and can be safely used in geriatric population,

Effective in patients with comorbid depression

Initiate a dose of 25 mg at bed time; can be increased to 75 mg per day at bedtime.

SEROTONIN-NOREPINEPHRINE REUPTAKE INHIBITORS (1 )

DULOXETINE- approved for painful diabetic neuropathy

It is also approved for generalized anxiety disorder, depression and fibromyalgia.

Starting dose 20-30 mg HSOD, can be titrated to a maximum dose of 60 mg daily at night

Nausea is a common side effect

SEROTONIN-NOREPINEPHRINE REUPTAKE INHIBITORS (2 )

VENLAFAXINE- is approved for generalized anxiety, panic disorder, depression and social anxiety

Effective in treating diabetic and other painful neuropathies

Starting dose is 37.5 mg at bed time, can be titrated to a maximum dose of 225 mg per day

Immediate release formulation can be used BD, extended release formulation once daily

TRAMADOL

Tramadol is a weak mu opioid receptor agonist and weakly inhibits serotonin and noradrenalin reuptake,

Tramadol is effective in DPN, PHN, radiculopathy and phantom limb pain,

Starting dose 50 mg BD, can be gradually increased to 100 mg QID

Common side effects include sedation, constipation, postural drop in BP and lowering of seizure threshold.

TOPICAL CAPSAICIN

Capsaicin depletes substance P and relieves neuropathic pain,

0.075% cream and 0.8% transdermal patch have been tested,

Effective in treating post herpetic neuralgia,

Commonest side effect is local skin irritation (burning, itching, rash, etc)

TOPICAL LIDOCAINE

Lidocaine 5% transdermal patch is approved for PHN, and is effective for other painful neuropathies too.

Gel formulations are also available

A maximum of three patches can be applied to the affected area and left in place for 12 hours,

No dose titration is necessary

Well tolerated, as so significant systemic absorption occurs

BOTULINUM TOXIN

Intradermal Botox injection has been tested in DPN, PHN and TN

Moderate success in small case series, further research is needed

Reasonably safe.

CONCLUSIONS

Several drugs are available to treat neuropathic pain,

Choice of drug depends on age, comorbid conditions (insomnia, depression, anxiety, etc) and the cause of neuropathic pain,

Start low, and gradually escalate the dose, until the desired effect is reached,

Side effects are mild and uncommon, mainly sedation and dizziness.

COMMENTS/QUERIES

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