What measures relieve postherpetic neuralgia?

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Clinical Inquiries

What measures relieve postherpetic neuralgia?

J Fam Pract. 2009 July;58(7):384d-384f

By

Neil Garroway, MD

Shalini Chhabra, MD, MPH

Suzanne Landis, MD, MPH

Deborah C. Skolnik, MLS

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References

1. saarto T, Wiffen PJ. Antidepressants for neuropathic pain. Cochrane Database Syst Rev. 2007;(4):CD005454.-

2. Alper BS, Lewis PR. Treatment of postherpetic neuralgia: a systematic review of the literature. J Fam Pract. 2002;51:121-128.

3. Dubinsky RM, Kabbani H, El-Chami Z, et al. Practice parameter: treatment of postherpetic neuralgia: an evidence-based report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2004;63:959-965.

4. Attal N, Cruccu G, Haanpaa M, et al. EFNS guidelines on pharmacological treatment of neuropathic pain. Eur J Neurol. 2006;13:1153-1169.

5. Hempenstall K, Nurmikko TJ, Johnson RW, et al. Analgesic therapy in postherpetic neuralgia: a quantitative systematic review. PLoS Med. 2005;2:e164.-

6. Wareham DW. Postherpetic neuralgia. BMJ Clin Evid. 2007;12:905-918.

7. van Seventer R, Feister HA, Young JP, et al. efficacy and tolerability of twice-daily pregabalin for treating pain and related sleep interference in postherpetic neuralgia: a 13-week, randomized trial. Curr Med Res Opin. 2006;22:375-384.

8. Dworkin RH, Corbin AE, Young JP, Jr, et al. Pregabalin for the treatment of postherpetic neuralgia; a randomized, placebo-controlled trial. Neurology. 2003;60:1274-1283.

9. Raja SN, Haythornwaite JA, Pappagallo M, et al. Opioids versus antidepressants in postherpetic neuralgia: a randomized, placebo-controlled trial. Neurology. 2002;59:1015-1021.

10. Khaliq W, Alam S, Puri N. Topical lidocaine for the treatment of postherpetic neuralgia. Cochrane Database Syst Rev. 2007;(2):CD004846.-

EVIDENCE-BASED ANSWER

Tricyclic antidepressants, gabapentin, and pregabalin effectively reduce pain (strength of recommendation [SOR]: A, at least 2 good-quality randomized controlled trials [RCTs] and/or meta-analyses). Opioids have demonstrated pain relief in 3 RCTs (SOR: A, consistent RCTs). Capsaicin and the lidocaine 5% patch relieve pain and decrease allodynia (SOR: B, recommendations from meta-analyses and lower-quality RCTs).

Evidence summary

Postherpetic neuralgia (PHN) is defined as pain lasting 1 to 3 months after resolution of acute herpes zoster (shingles) rash. It occurs in approximately 10% to 15% of patients and can cause significant morbidity.

FAST TRACK

Tricyclic antidepressants, anticonvulsants, and narcotics all reduce postherpetic pain.

Tricyclic antidepressants provide effective pain relief

Five systematic reviews have concluded that tricyclic antidepressants (TCAs) are effective treatments for PHN.^1-5 Amitriptyline, the best studied TCA, provides at least moderate pain relief in two-thirds of patients with a pooled number needed to treat (NNT) for TCAs of 2.64 (95% confidence interval [CI], 2.1-3.54)⁵ (TABLE).

Selective serotonin reuptake inhibitors—including fluoxetine, paroxetine, citalopram, and sertraline—have been studied in a variety of neuropathic pain syndromes, but not for treating PHN.¹

TABLE
What’s the NNT for drugs used to treat postherpetic neuralgia?

CLASS	DRUG	DOSE	NNT	SIDE EFFECTS
Tricyclic antidepressants⁵	Amitriptyline	Up to 150 mg/d (mean 120 mg/d)	2.64	Sedation, dry mouth, blurred vision, constipation, urinary retention
	Nortriptyline	Up to 150 mg/d (mean 89 mg/d)
	Desipramine	Up to 150 mg/d (mean 65-73 mg/d)
Anticonvulsants^3,5	Gabapentin	1800-3600 mg/d	2.8-5.3	Somnolence, dizziness, edema, dry mouth
Anticonvulsants^3,5	Pregabalin	150-600 mg/d	4.93	Somnolence, dizziness, edema, dry mouth
Opioids⁵	Oxycodone	Variable	2.67	Constipation, nausea, vomiting, sedation, dizziness, dependence
	Long-acting morphine/methadone	15-225 mg/d (morphine) (mean 91 mg/d for morphine, 15 mg/d for methadone)	2.67
	Tramadol	100-400 mg/d (mean 275 mg/d)	4.76	Dependence
Topicals⁵	Capsaicin 0.075% cream	Applied 3-4 times per day	3.26	Burning skin
Topicals⁵	Lidocaine 5% extended release patch	Max 3 patches per day	2.0	Mild skin reaction
NNT, number needed to treat.

Anticonvulsants help, too

Five systematic reviews found gabapentin to be effective, with a range of NNT from 2.8 to 5.3 for as much as 50% pain reduction based on the visual analog score (VAS).^2-6 Pregabalin is also effective, with an NNT of 4.93 (95% CI, 3.34-6.07) for up to 50% pain reduction.^7,8 Limited data are available concerning the effectiveness of valproate.⁵

A look at the role of narcotics

Four systematic reviews found that controlled-release oxycodone reduced pain by 50%, based on the VAS.^2-5 Another systematic review reported only limited evidence of effectiveness.⁶ In pooled results from systematic reviews, opioids decreased pain by 50% on the VAS (NNT=2.67; 95% CI, 2.10-3.77).⁶

Evidence-based answers from the Family Physicians Inquiries Network

What measures relieve postherpetic neuralgia?

References

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