What is the incidence of pruritus as a side effect of bupivacaine?

Incidence of Pruritus as a Side Effect of Bupivacaine

Bupivacaine alone rarely causes pruritus as a side effect, but when combined with opioids in neuraxial anesthesia, the incidence of pruritus increases significantly to 75-100%, with bupivacaine actually showing a protective effect compared to other local anesthetics. 1, 2

Incidence of Bupivacaine-Associated Pruritus

Bupivacaine Alone

• Bupivacaine by itself has not been specifically associated with a high incidence of pruritus in the available guidelines and research
• When used alone intrathecally, bupivacaine is not commonly reported to cause significant pruritus

Bupivacaine with Opioids

• The combination of intrathecal bupivacaine with opioids (particularly fentanyl) is associated with a significant incidence of pruritus:
  • 75% incidence when bupivacaine is combined with fentanyl 2
  • 95-100% incidence when fentanyl is used alone intrathecally 3, 2
  • Bupivacaine actually reduces the incidence of pruritus compared to fentanyl alone (75% vs 95-100%) 3

Comparative Incidence with Different Local Anesthetics

When combined with intrathecal fentanyl, different local anesthetics show varying effects on pruritus:

• Procaine + fentanyl: 55% incidence with higher severity scores (VPS 37) 4
• Bupivacaine + fentanyl: 55% incidence with moderate severity scores (VPS 20) 4
• Lidocaine + fentanyl: 21% incidence with lower severity scores (VPS 16) 4
• Ropivacaine + fentanyl: 85% incidence 2

Distribution and Characteristics of Pruritus

• When bupivacaine is combined with fentanyl, pruritus is most commonly facial (25% of cases) 3
• Bupivacaine reduces pruritus on all parts of the body except the face when combined with opioids 3
• Pruritus typically develops within 30 minutes of administration 2

Management of Bupivacaine-Associated Pruritus

For patients experiencing pruritus associated with bupivacaine (particularly when combined with opioids):

1. First-line treatments:

   • Topical antipruritic agents containing menthol 0.5% 1
   • Topical corticosteroids (mometasone furoate 0.1% or betamethasone valerate 0.1%) 1
   • Non-sedating antihistamines (loratadine 10 mg daily) for daytime symptoms 1
   • First-generation antihistamines (diphenhydramine 25-50 mg or hydroxyzine 25-50 mg) for nighttime symptoms 1

2. Second-line treatments:

   • Antiepileptic agents (pregabalin 25-150 mg daily or gabapentin 900-3600 mg daily) 1
   • Nalbuphine (a mu-receptor antagonist and kappa-receptor agonist) has been shown to reduce opioid-induced pruritus when added to intrathecal bupivacaine plus morphine 5

Prevention Strategies

• Adding bupivacaine to intrathecal fentanyl reduces the incidence and severity of pruritus compared to fentanyl alone 3, 2
• Ondansetron (4-8 mg IV) has not been shown to prevent pruritus induced by intrathecal fentanyl-bupivacaine combinations 6
• Nalbuphine added to intrathecal bupivacaine plus morphine significantly reduces the incidence and severity of pruritus without affecting analgesic efficacy 5

Clinical Implications

• When using neuraxial anesthesia, be aware that the combination of bupivacaine with opioids carries a significant risk of pruritus
• Bupivacaine actually has a protective effect against pruritus compared to fentanyl alone or other local anesthetic-opioid combinations
• Facial pruritus is less likely to be prevented by the addition of bupivacaine to opioids
• Consider prophylactic measures for high-risk patients receiving neuraxial opioids with bupivacaine