Can benadryl cause heart attacks?

[goblue1972]

Hi, my question to everyone is: if a patient is diagnosed with chronic heart failure and has high blood pressure and is prescribed benadryl, and a week later the patient dies, can this be caused by the patients body going into a sleep state and rapid heart beat due to the benadryl prescribed?

 

[VCU07]

Hi, my question to everyone is: if a patient is diagnosed with chronic heart failure and has high blood pressure and is prescribed benadryl, and a week later the patient dies, can this be caused by the patients body going into a sleep state and rapid heart beat due to the benadryl prescribed?

You must remember that benadryl has anticholinergic properties. It can block the binding of Ach to M2 receptors found in the heart. This would most likely increase the heart rate, which would be detrementalfor a person recently diagnosed with CHF. In addition to this, there could be a drug drug interaction with beta blockers, which are commonly prescribed after a MI.

 

[Pilot]

not to mention the potential for volume overload 2° to urinary retention and backflow further damaging the kidney's ability to filter and excrete. Sure, it's a long shot, but we are speaking theoretically here.

 

[dgroulx]

Hi, my question to everyone is: if a patient is diagnosed with chronic heart failure and has high blood pressure and is prescribed benadryl, and a week later the patient dies, can this be caused by the patients body going into a sleep state and rapid heart beat due to the benadryl prescribed?

It is most likely a coincidence. Benadryl can cause some tachycardia, but life threatening adverse affects aren't going to happen unless the patient OD'd on it. If even a small number of CHF patients died from Benadryl, it would be pulled from the market.

 

[MAXHARDC]

You must remember that benadryl has anticholinergic properties. It can block the binding of Ach to M2 receptors found in the heart. This would most likely increase the heart rate, which would be detrementalfor a person recently diagnosed with CHF. In addition to this, there could be a drug drug interaction with beta blockers, which are commonly prescribed after a MI.

Beta receptors are embedded in the cell's outer phospholipid membrane. The stability of the membrane has a lot to do with the functionality of the receptors. It turns out that methylation of the phospholipids is stimulated by the binding of beta agonists to their receptors. The body recognizes these methylated phospholipids as foreign, and breaks them down with an enzyme called phospholipase A2. This alters the structure of the outer membrane and results in desensitizaton of the beta receptors (1). Conversely, agents that inhibit phospholipase A2 slow desensitization.

It turns out that cationic ampiphylic drugs are well known for their ability to inhibit phospholipase A2. Ketotifen is a cationic ampiphylic drug, so is diphenhydramine (Benadryl)

Max


(1) Prog Clin Biol Res. 1981;63:383-8.
Phospholipid methylation: a possible mechanism of signal transduction across biomembranes.
Hirata F, Tallman JF, Henneberry RC, Mallorga P, Strittmatter WJ, Axelrod J