Herpes
Canadian Guidelines on Sexually Transmitted Infections - Genital Herpes simplex virus Infections
Primary episode
- No role for topical acyclovir.
Herpes simplex II
Herpes simplex I
Severe/hospitalized
| Therapy | Dose | Duration |
|---|---|---|
| Acyclovir | 5mg/kg IV q8h | Switch to oral agent when clinical improvement to complete course of therapy |
Mild-moderate
| Therapy | Dose | Duration |
|---|---|---|
| Valacyclovir | 1g PO bid | 7-10 days |
| or | ||
| Famciclovir | 250mg PO tid | 5-7 days |
| or | ||
| Acyclovir | 400mg PO tid | 7-10 days |
Recurrent
Usual PathogensHerpes simplex II
Herpes simplex I
Mild/infrequent
No therapy
Episodic
- For patients with infrequent (< 6 episodes/year) moderate to severe recurrences with prodrome. Must have:
- drug on hand
- compliant patient
- initiation of therapy within hours of prodromal symptoms (maximum 24 hours). No proven efficacy if started after 24 hours.
| Therapy | Dose | Duration |
|---|---|---|
| Valacyclovir | 500mg PO bid or | 3 days |
| 1000mg PO daily | 3 days |
Alternative
| Therapy | Dose | Duration |
|---|---|---|
| Famciclovir | 125mg PO bid or | 5 days |
| 1000mg PO bid | 1 day | |
| or | ||
| Acyclovir | 400mg PO tid or | 5 days |
| 800mg PO tid | 2 days |
Suppressive
- If symptom free for 6-12 months, reassess rate of recurrences and need for continuing suppressive therapy.
| Therapy | Dose | Duration |
|---|---|---|
| Valacyclovir | 6-9 episodes/year: 500mg PO daily | 6-12 months |
| ≥ 10 episodes/year: 1g PO daily | 6-12 months | |
| or | ||
| Famciclovir | 250mg PO bid | 6-12 months |
| or | ||
| Acyclovir | 400mg PO bid | 6-12 months |
Recurrent, immunocompromised
Usual PathogensHerpes simplex II
Herpes simplex I
Episodic
| Therapy | Dose | Duration |
|---|---|---|
| Valacyclovir | 1000mg PO bid | 5-10 days |
| or | ||
| Famciclovir | 500mg PO bid | 5-10 days |
| or | ||
| Acyclovir | 400mg PO tid | 5-10 days |
Suppressive
| Therapy | Dose | Duration |
|---|---|---|
| Valacyclovir | 500mg PO bid | 6-12 months |
| or | ||
| Famciclovir | 500mg PO bid | 6-12 months |
| or | ||
| Acyclovir | 400-800mg PO bid-tid | 6-12 months |
Pregnancy
- Early pregnancy:
- no data that acyclovir will prevent congenital herpes (rare event).
- Infectious Diseases consult recommended.
- Late pregnancy:
- Primary episode → 50% risk of transmission to infant.
- Recurrent → maximum 4% risk to infant.
- HSV infection in infant has 50% mortality.
- If active lesions at time of labour, caesarean section recommended.
Primary episode
- Valacyclovir is safe in pregnancy and preferred over acyclovir due to less frequent dosing.
Usual Pathogens
Herpes simplex II
Herpes simplex I
| Therapy | Dose | Duration |
|---|---|---|
| Acyclovir | 5mg/kg IV q8h | Switch to oral agent when clinical improvement to complete course of therapy |
| or | ||
| Valacyclovir | 1g PO bid | 7-10 days |
| or | ||
| Acyclovir | 400mg PO tid | 7-10 days |
Recurrent
- If previous recurrent disease but no outbreaks during pregnancy, suppressive therapy with valacyclovir beginning at 36 weeks gestation until delivery is recommended to prevent recurrence at time of delivery, decrease risk of viral shedding and need for caesarean due to HSV.
- Valacyclovir is safe in pregnancy and preferred over acyclovir due to less frequent dosing.
Usual Pathogens
Herpes simplex II
Herpes simplex I
| Therapy | Dose | Duration |
|---|---|---|
| Valacyclovir | 500mg PO bid | Continue until delivery |
| or | ||
| Acyclovir | 400mg PO tid | Continue until delivery |