Tizanidine/Clonidine; Guanadrel; Guanethidine Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Both of your medicines can lower your blood pressure.

What might happen:

You may be at an increased risk of severe low blood pressure and drowsiness.

What you should do about this interaction:

Let your healthcare professional (e.g. doctor or pharmacist) know right away that you are using these medicines together. To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. Let your doctor know if you have any fainting or dizziness episodes. Your doctor may want to change the dose of your tizanidine. Use caution when performing tasks that require alertness.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Zanaflex (tizanidine hydrochloride) US prescribing information. Acordia Therapeutics, Inc. November 7, 2013.
  • 2.Publow SW, Branam DL. Hypotension and bradycardia associated with concomitant tizanidine and lisinopril therapy. Am J Health Syst Pharm 2010 Oct 01;67(19):1606-10.
  • 3.Kao CD, Chang JB, Chen JT, Wu ZA, Shan DE, Liao KK. Hypotension due to interaction between lisinopril and tizanidine. Ann Pharmacother 2004 Nov; 38(11):1840-3.
  • 4.Johnson TR, Tobias JD. Hypotension following the initiation of tizanidine in a patient treated with an angiotensin converting enzyme inhibitor for chronic hypertension. J Child Neurol 2000 Dec;15(12):818-9.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.