Hayley Hutton Paediatric registrar

The use of Gabapentin for the management of pain in Guillain-Barré Syndrome in the paediatric setting.

29 October 2014

Gabapentin

The Good

The Bad

And the Unknown...

The unknown...

Does OUR off label use of Gabapentin

in Neuropathic pain stem from illicit marketing

or is there some scientific evidence?

Efficacy of Gabapentin?

❖ Minimal paediatric data

❖ None out of Africa

❖ Pandey et al: Efficacy and safety of Gabapentin in

adults with severe Guillain-Barré Syndrome

❖ Some proven efficacy in conditions such as: complex

regional pain syndromes; peri operatively; post

herpetic neuralgia.

Methodology

❖ Observational, retrospective study

❖ All patients admitted to RXH with Guillain- Barré

syndrome 2002 - 2012

❖ Medical records and Prescription charts reviewed

❖ Data was collected using Epidata and analysed using

STATA v12.0

Incidence at RXH

0

4

8

12

16

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

No.

Year

Age of population

0

5

10

15

20

25

0 1 2 3 4 5 6 7 8 9 10 11 12

Age in years

No.

Characteristics of Hospital stay

Characteristic Overall Gaba Carba Neither P-value

Length of hospital stay 14 days

(+-43) 48 45 10 0.85

No. Needing PICU 41% 64 59 17

Length of PICU stay 21 days

(+-33) 26 31 15 0.18

No. Needing ventilatory support 31% 50 52 8

No. Needing a tracheostomy 28% 45 52 1

Duration on tracheostomy 54 days 57 58 31 0.68

Characteristics of Pain

Characteristic Overall Gaba Carba Neither P-value

Proportion with documented

pain 76% 100 86 54 0.67

Mean no. Analgesics used 2.3 (+- 1.8) 3.4 3.2 1.2 0.67

Duration of pain 4 days (+-8) 12.7 13.4 4.2 0.90

Episodes of breakthrough pain 55% 77 79 4

Caregiver at bedside 93% 86 93 95

Limitations of the study

❖ Retrospective nature

❖ Lack of standardized methods to measure pain

Conclusions of the study

❖ Assessment of pain is suboptimal

❖ Dramatic increase in the use of Gabapentin at RXH

Looking ahead...

❖ Randomized, double blinded control trial

❖ Gabapentin vs Carbamazepine for the management of

neuropathic pain

❖ Guillain-Barré Syndrome

A very big thank you to Prof Jo Wilmshurst and Prof JennyThomas

References:

❖ Walco GA, Dworkin RH, Krane EJ, LeBel AA, Treede RD. Neuropathic pain in children: special considerations.

Mayo Clinic Proceedings [Internet]. 2010 [cited 2012 Sep 17]. page S33–S41. Available from:

http://171.67.112.83/content/85/3_suppl/S33.short

❖ Korinthenberg R, Mönting JS. Natural history and treatment effects in Guillain-Barré syndrome: a multicentre

study. Arch Dis Child. 1996 Apr 1;74(4):281–7

❖ Kar S, Menon L, Mondal M, Mukherjee S, Pal R, Sarbapalli D, et al. Spectrum of Guillain-Barre syndrome in tertiary

care hospital at Kolkata. Journal of Natural Science, Biology and Medicine. 2011 Dec;2(2):211.

❖ Moulin DE, Hagen N, Feasby TE, Amireh R, Hahn A. Pain in Guillain-Barré syndrome. Neurology. 1997;48(2):328–

31.

❖ Asbury AK, Cornblath DR. Assessment of current diagnostic criteria for Guillain-Barré syndrome. Annals of

Neurology. 199;27(S1):21-24.

❖ Pandey CK, Raza M, Tripathi M, Navkar DV, Kumar A, Singh UK. The Comparative evaluation of Gabapentin and

Carbamazepine for Pain Management in Guillain-Barré syndrome patients in the Intensive Care Unit.

Anesthesia and Analgesia. 2005 Jul;101(1):220-5

Pregabalin?

❖ Very similar in action to Gabapentin

❖ Has been thought of as the superior pharmacological

agent

❖ But...

❖ Safety and efficacy has not been established in children

❖ Not licensed for use in children <12 years

❖ Cost

Gabapentin fact file

❖ Derivative of GABA

❖ Absorbed via GIT with 80% bioavailability

❖ Distribution: not bound to plasma proteins, penetrates

CSF

❖ Metabolism: Negligible

❖ Excretion: Renal excretion, t1/2

❖ Adverse effects: dizziness and somnolence, dry mouth,

oedema, blurred vision (dose dependent/reversible)

❖ MOA:*Inhibition of Ca channels

Pain rating tools

❖ Fraught with difficulty

❖ Few validated tools

❖ Neuropathic pain

❖ Self report requires an alert and communicative child

❖ Autonomic dysfunction

❖ FLACC; Self report; NCCPC-R