Pharmacologic Management of Shivering
Meperidine (Demerol) is the most effective single pharmacologic agent for treating established shivering, with doses of 25-50 mg IV stopping shivering in nearly 100% of patients within 5 minutes. 1, 2
Why Meperidine is Superior
Among all opioid analgesics, meperidine uniquely both lowers the shivering threshold and directly suppresses shivering through mechanisms beyond its analgesic properties. 1 This special antishivering activity makes it approximately 2,800 times more effective at inhibiting shivering than would be predicted by its analgesic potency alone when compared to other opioids like sufentanil. 3
Clinical Efficacy Data
At 1 minute post-administration: Meperidine 25 mg achieves a number-needed-to-treat (NNT) of 2.7, meaning fewer than 3 patients need treatment for one to stop shivering. 4
At 5 minutes post-administration: The NNT improves to 1.3, with a relative risk of 9.6 for stopping shivering compared to placebo. 4
At 10 minutes: The NNT is 1.5, demonstrating sustained rapid efficacy. 4
Overall success rate: A single 25 mg dose stops shivering in 90% of patients, with the remaining 10% responding to a second dose, achieving near 100% efficacy. 5
Dosing Strategy
Start with meperidine 25-50 mg IV as the initial dose. 2 If shivering persists after 5 minutes, a second dose can be administered. 5 This approach provides rapid control while minimizing cumulative opioid exposure.
Combination Therapy for Enhanced Effect
When combined with high-dose buspirone (30 mg), meperidine can reduce the shivering threshold to as low as 33°C, providing synergistic benefit for patients requiring aggressive temperature management. 1 However, this combination requires caution in patients at risk for seizures or those not under continuous monitoring. 1
Alternative and Adjunctive Agents
Other Effective Pharmacologic Options
Clonidine 150 mcg IV: Achieves 100% efficacy with an NNT of 1.3 at 5 minutes, comparable to meperidine but with different side effect profile (potential for hypotension and bradycardia). 4, 5
Dexmedetomidine: Effective for shivering prevention and treatment, particularly useful when sedation is acceptable or desired. 6
Doxapram 100 mg IV: NNT of 1.7 at 5 minutes, though less commonly used. 4
Non-Sedating Adjuncts
Magnesium sulfate and acetaminophen are safe adjuncts with favorable side effect profiles, but when used alone are typically insufficient to suppress clinically significant shivering. 1, 7 These agents only slightly reduce the shivering threshold and should be considered as part of a multimodal approach rather than monotherapy. 1
Important Safety Considerations
Seizure Risk
Exercise caution with meperidine in patients at risk for seizures, particularly when used in combination with buspirone or in those not continuously monitored. 1 The combination of meperidine and buspirone lowers seizure threshold. 8
Sedation Trade-offs
All opioids and sedatives blunt shivering at the inherent expense of sedation and potential hemodynamic effects. 1 For most patients receiving targeted temperature management, the initial approach is intensification of sedation if hemodynamically tolerated, before adding specific antishivering agents. 1
Stepwise Approach
- First-line: Meperidine 25-50 mg IV for rapid control of established shivering 2
- If inadequate response: Repeat meperidine dose after 5 minutes 5
- For refractory cases: Consider adding buspirone 30 mg (if seizure risk acceptable) 1 or escalate to neuromuscular blockade 1
- Adjunctive measures: Add acetaminophen and magnesium sulfate for their favorable safety profiles, though limited efficacy 1
When Meperidine Fails
Neuromuscular blockade (NMB) is the most effective abortive measure for refractory shivering when pharmacologic approaches fail. 1 This is particularly appropriate when active temperature management is expected to be transient, such as in post-cardiac arrest care. 1 When using NMB, continuous EEG monitoring is essential as it masks clinical seizure manifestations. 1