Can dextromethorphan increase blood pressure?

Does Dextromethorphan Increase Blood Pressure?

Dextromethorphan is not typically associated with significant blood pressure increases in normal therapeutic doses, but it can cause hypertension in overdose situations or when used in combination with certain medications.

Effects on Blood Pressure

• Dextromethorphan is not listed among medications known to increase blood pressure in major hypertension guidelines 1, 2
• In contrast to many over-the-counter decongestants that are known to raise blood pressure, dextromethorphan does not appear on lists of substances that commonly elevate blood pressure 1
• In overdose situations, particularly in pediatric patients, dextromethorphan can cause hypertension as part of its toxicity profile 3

Research on Blood Pressure Effects

• Interestingly, low-dose dextromethorphan has been studied as a potential antihypertensive agent when combined with amlodipine, showing additive blood pressure-lowering effects in hypertensive patients 4
• Animal studies suggest that dextromethorphan may actually reduce blood pressure through inhibition of NADPH oxidase, potentially enhancing vascular protection 5
• One study showed that preoperative oral dextromethorphan (30 mg) attenuated tourniquet-induced blood pressure and heart rate increases during surgery under general anesthesia 6

Clinical Considerations

• When evaluating medications that may contribute to hypertension, focus should be on known agents listed in hypertension guidelines, such as:

  • Decongestants (pseudoephedrine, phenylephrine)
  • NSAIDs
  • Oral contraceptives
  • Systemic corticosteroids
  • Stimulants
  • Certain antidepressants 1, 2

• Medications that commonly raise blood pressure include:

  • Alcohol
  • Antidepressants (particularly SNRIs like venlafaxine)
  • Decongestants
  • Herbal supplements
  • NSAIDs
  • Oral contraceptives
  • Stimulants
  • Tobacco 1, 7

Special Populations and Precautions

• Patients with pre-existing hypertension should be monitored when starting any new medication, including dextromethorphan, even though it's not typically associated with blood pressure changes 2
• In pediatric overdose cases, dextromethorphan polistirex (extended-release formulation) has been reported to cause hypertension as part of its toxicity profile 3
• Patients with cardiovascular disease should exercise caution with any cough and cold medications, particularly those containing decongestants rather than dextromethorphan alone 1

Management Approach

• If blood pressure elevation occurs with dextromethorphan use:
  • Consider discontinuing the medication if clinically appropriate
  • Evaluate for potential drug interactions that might potentiate blood pressure effects
  • Consider alternative cough suppressants if needed 2
• Regular blood pressure monitoring is recommended when starting any new medication in patients with hypertension, even those not typically associated with blood pressure changes 2