Shingles Pain Management
First-Line Antiviral Therapy
For acute shingles pain management, initiate oral valacyclovir 1000 mg three times daily for 7 days as soon as possible after symptom onset, ideally within 72 hours of rash appearance. 1, 2
Antiviral Treatment Options
Recommended oral antivirals for uncomplicated herpes zoster:
- Valacyclovir 1000 mg three times daily for 7 days (preferred due to superior pain reduction and convenient dosing) 2, 3
- Famciclovir 500 mg every 8 hours for 7 days 4, 3
- Acyclovir 800 mg five times daily for 7 days (less convenient dosing) 2, 5
Key evidence: Valacyclovir demonstrates 36% risk reduction in herpes zoster-associated pain at 21-30 days compared to acyclovir (NNT=3), with significantly faster resolution of postherpetic neuralgia 3. Famciclovir shows 46% risk reduction in pain at 28-30 days versus acyclovir (NNT=3) 3. Both agents are superior to acyclovir for pain control while maintaining comparable safety profiles 6, 3.
Timing Considerations
- Initiate treatment within 72 hours of rash onset for maximum efficacy 1, 4, 7
- Treatment may still provide benefit when started beyond 72 hours, particularly for pain reduction 8
- Continue treatment for minimum 7-10 days or until all lesions have scabbed 1, 2
- Consider extending treatment duration if new lesions continue forming or healing is incomplete 2
Severe or Complicated Disease
For disseminated, multi-dermatomal, ophthalmic, or visceral herpes zoster, administer intravenous acyclovir 5-10 mg/kg every 8 hours until clinical improvement, then switch to oral therapy. 2
Indications for IV Therapy
- Disseminated infection 1, 2
- Ophthalmic involvement (requires ophthalmology referral) 5, 7
- Immunocompromised patients with severe disease 2
- Complications including encephalitis, pneumonitis, or hepatitis 9
Treatment approach: Continue IV acyclovir until clinical resolution occurs, then transition to oral antiviral to complete 7-10 day course 2. In immunocompromised patients, consider temporary reduction in immunosuppressive medications during treatment 1, 2.
Acute Pain Management
Adjunctive Analgesic Therapy
For moderate to severe acute pain during the vesicular phase:
- Gabapentin as first-line neuropathic pain agent (titrate to 2400 mg daily in divided doses) 9
- Narcotics may be required for adequate pain control during acute phase 5
- Consider short-term corticosteroids (prednisone) as adjunct to antivirals in select cases of severe, widespread disease 1
Important caveat: Corticosteroid use carries significant risks in elderly patients and should be avoided in immunocompromised individuals due to increased risk of disseminated infection 1. The benefit of corticosteroids for preventing postherpetic neuralgia remains modest 5.
Postherpetic Neuralgia Management
For pain persisting beyond 90 days after acute herpes zoster (postherpetic neuralgia), initiate gabapentin as first-line pharmacological treatment. 9
Treatment Algorithm for Postherpetic Neuralgia
First-line options:
- Gabapentin (typical adult regimen titrates to 2400 mg per day in divided doses; also improves sleep) 9
- Topical capsaicin 8% dermal patch (single 30-minute application) 9
- Topical lidocaine patches 5, 7
Second-line options if inadequate response to gabapentin:
- Pregabalin (specifically for post-herpetic neuralgia) 9
- Tricyclic antidepressants in low doses 9, 5, 7
- Serotonin-norepinephrine reuptake inhibitors 9
Non-pharmacological interventions:
- Cognitive behavioral therapy (promotes adaptive behaviors and addresses maladaptive pain responses) 9
- Physical and occupational therapy 9
- Hypnosis for neuropathic pain 9
Special Populations
Immunocompromised Patients
All immunocompromised patients with herpes zoster require antiviral treatment regardless of timing of presentation. 2
- HIV-infected patients: Oral famciclovir 500 mg twice daily for 7 days or valacyclovir 1000 mg three times daily for 7 days 2, 4
- For disseminated disease: IV acyclovir 5-10 mg/kg every 8 hours with temporary reduction in immunosuppression 1, 2
- Monitor closely for dissemination and visceral complications 2
- Immunosuppression may be restarted after commencing anti-VZV therapy and resolution of skin vesicles 2
Renal Impairment
Dose adjustment required based on creatinine clearance to prevent acute renal failure: 4
- CrCl ≥40 mL/min: Standard dosing
- CrCl 20-39 mL/min: Reduce frequency to every 24 hours
- CrCl <20 mL/min: Further dose reduction required
- Hemodialysis: Administer dose following each dialysis session
Critical warning: Cases of acute renal failure have been reported in patients with underlying renal disease receiving inappropriately high doses 4.
Acyclovir-Resistant Cases
For suspected acyclovir-resistant herpes zoster, administer foscarnet 40 mg/kg IV every 8 hours (acyclovir-resistant isolates are routinely cross-resistant to ganciclovir) 9, 2.
Prevention Strategies
Vaccination
The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older regardless of prior herpes zoster episodes. 1, 2, 7
- Vaccination can be considered after recovery from acute episode to prevent future recurrences 1
- Significantly reduces incidence of herpes zoster and postherpetic neuralgia 7
Post-Exposure Prophylaxis
For varicella-susceptible patients exposed to active varicella zoster infection:
- Varicella zoster immunoglobulin within 96 hours of exposure (preferred) 1, 2
- If immunoglobulin unavailable or >96 hours elapsed: 7-day course of oral acyclovir beginning 7-10 days after exposure 1, 2
Common Pitfalls to Avoid
- Do not use topical antiviral therapy as it is substantially less effective than systemic therapy 1
- Do not delay treatment waiting for laboratory confirmation in typical presentations; clinical diagnosis is sufficient in immunocompetent patients 1
- Do not underdose antivirals in patients with normal renal function, as this reduces efficacy 3
- Do not assume antivirals eradicate latent virus; they control symptoms and reduce complications but do not eliminate VZV from dorsal root ganglia 1, 5
- Do not prescribe acyclovir as first-line when valacyclovir or famciclovir are available, given their superior pain reduction and more convenient dosing 3