Can clonidine (antihypertensive medication) cause palpitations and shivering?

Clonidine Can Cause Palpitations and Shivering

Yes, clonidine can cause palpitations and shivering as adverse effects. While clonidine is primarily known for causing bradycardia, it can paradoxically cause palpitations and shivering through several mechanisms related to its central alpha-2 agonist properties and sympathetic nervous system effects.

Cardiovascular Effects of Clonidine

• Clonidine commonly causes bradycardia (slow heart rate), which occurs in approximately 76% of patients taking the medication, with a median onset of 2.5 hours after ingestion 1

• Palpitations can occur due to:

  • Rebound sympathetic activity, especially when doses are missed or with abrupt discontinuation 2
  • Irregular heart rhythms that may develop as a side effect of the medication 3
  • Fluctuations in heart rate that can be perceived as palpitations by patients 4

• Clonidine can affect sinus node function, causing significant changes in heart rate and rhythm that may be experienced as palpitations 3

Shivering and Temperature Regulation Effects

• Shivering is a recognized side effect of clonidine related to its central nervous system effects 2
• Clonidine affects the body's thermoregulatory mechanisms through its action on alpha-2 receptors in the central nervous system 1
• Temperature dysregulation can manifest as shivering, particularly during initiation of therapy or with dosage changes 2

Risk Factors for Experiencing These Side Effects

• Patients with renal insufficiency are at higher risk for bradycardia and associated rhythm disturbances that may be perceived as palpitations 5
• Patients with pre-existing sinus node dysfunction are more vulnerable to cardiac effects 5
• Concurrent use of other sympatholytic agents can increase the risk of bradycardia and associated symptoms 5
• Elderly patients are more susceptible to central nervous system adverse effects, including shivering 2

Clinical Considerations

• Guidelines note that clonidine is "generally reserved as last-line because of significant CNS adverse effects, especially in older adults" 2
• Abrupt discontinuation of clonidine must be avoided as it can induce hypertensive crisis and significant sympathetic rebound that worsens palpitations 2
• Clonidine must be tapered to avoid rebound hypertension and associated cardiovascular symptoms 2

Management of These Side Effects

• For patients experiencing palpitations or shivering:

  • Consider dose reduction if symptoms are mild to moderate 5
  • Evaluate for underlying cardiac conditions that might be exacerbated by clonidine 3
  • Ensure proper dosing schedule to minimize fluctuations in drug levels 2
  • Monitor for signs of more serious bradycardia, which may require discontinuation 6

• For severe symptoms:

  • Discontinuation may be necessary, but must be done gradually 2
  • Alternative antihypertensive medications may be considered if these side effects are intolerable 2

Important Precautions

• Clonidine should be used with caution in patients with AV conduction disease due to its effects on cardiac conduction 4
• Patients should be educated about the importance of not missing doses or stopping the medication abruptly 2
• Regular monitoring of heart rate and symptoms is important, especially during initiation and dose adjustments 5

While bradycardia is the more commonly recognized cardiac effect of clonidine, palpitations and shivering are established adverse effects that can significantly impact patient comfort and medication adherence.