Here I will discuss the propranolol and ciprofloxacin interaction by presented a brief case scenario. A 59 year old female with a 40 year history of smoking a pack per day presents today, complaining of worsening respiratory status.  She is having a lot of dyspnea.  Her COPD has responded fairly well to the long acting cholinergic tiotropium up until this time, so this is new to her.  She has never been motivated to quit smoking and when you ask her about it, she still isn’t motivated.

About a week ago, she was placed on ciprofloxacin for a urinary tract infection.  She has been on 4-5 different antibiotics for frequent UTI’s in the last year.  Since this infection started, she reports that she cannot catch her breath sometimes.

Her other diagnoses include; GERD, essential tremor, hypertension.

Medications include:

• Ranitidine
• Propranolol
• Omeprazole
• Lisinopril
• Amlodipine
• Tiotropium
• Albuterol as needed
• Ciprofloxacin

There certainly could be a lot of possibilities here that would cause worsening breathing, but if I didn’t pay attention to the medications, I wouldn’t be doing my job.  Ciprofloxacin can inhibit CYP1A2.  Propranolol is a CYP1A2 substrate.  By starting ciprofloxacin in this patient, this potentially increased the concentrations of propranolol and could impact respiratory status.  Remember that beta blockers (specifically beta-2 blockade) can cause airways to shrink. In a patient who already has difficulties breathing, this could be the difference between comfortable breathing and respiratory distress.  In this scenario, you could make the argument that propranolol should be avoided altogether if possible.  A frequently used alternative for essential tremor is primidone.  It should be noted that this medication doesn’t come without potential adverse effects and interactions as well.

The propranolol and ciprofloxacin interaction is considered a contraindication to using them together, but paying attention, educating the patient, and monitoring for adverse effects from the propranolol would be an appropriate action.  Here’s another excellent post that compares some of the differences between the beta blockers.