Analgesia

For pain due to red-back spider envenoming, use:

paracetamol immediate-release 1 g (child: 15 mg/kg up to 1 g) orally, four times daily, with a minimum interval of 4 hours between doses. Maximum dose is 4 g (child: 60 mg/kg up to 4 g) in 24 hours red-back spider bite paracetamol

PLUS

ibuprofen 400 to 800 mg (child 3 months or older: 8 to 10 mg/kg up to 400 mg) orally, every 8 hours up to a maximum of 2400 mg (child: 30 mg/kg up to 2400 mg) daily1 red-back spider bite ibuprofen

If this is ineffective, add an oral opioid analgesic:

oxycodone immediate-release 2.5 to 10 mg (child: 0.1 to 0.2 mg/kg up to 5 mg) orally, every 4 hours. Use the lower end of the dose range for patients in a community setting, or elderly, cachectic or frail patients. red-back spider bite oxycodone

To determine the need for, and appropriateness of, repeat doses of opioids, monitor the patient’s pain intensity, sedation score and objective measures of respiratory function (eg oxygen saturation, respiratory rate).

If oral analgesia is inadequate for severe pain, use an intravenous opioid analgesic. The Analgesic guidelines give detailed advice on dosage and administration of intravenous opioid analgesia for acute pain in adults and children.

For persistent or intractable pain due to red-back spider bite (eg if doses of opioids higher than recommended are required within 1 hour), review the patient’s clinical condition and seek advice from a clinical toxicologist.

1 A different NSAID may be preferable based on patient factors, including increased risk of bleeding, and risk of cardiovascular or gastrointestinal toxicity; see Nonsteroidal anti-inflammatory drugs (NSAIDs) in pain management.Return