There are lots of ways to get medicine into your body. Swallowing pills is the most obvious route. Injections are also understandable. Topical seems a bit harder for people to comprehend, though. Even the FDA seemed surprised to learn that sunscreen ingredients can be absorbed through the skin. Another way drugs can get into the blood stream is through rectal or anal absorption. This reader experienced a dreadful drug interaction while taking the beta blocker metoprolol and then treating hemorrhoids with Preparation H.
Rectal and Anal Absorption of Preparation H?
Q. Watch out for serious drug interactions with Preparation H! A few years ago, I was taking a beta blocker drug called metoprolol for a heart rhythm problem. During that time, I developed hemorrhoids and used Preparation H as directed.
I had used this product in the past with no problems. Consequently, I didn’t think to read the warning about interactions with beta blockers. The second day I got up in the night to use the bathroom and fainted. My face hit the countertop as I fell and I damaged my face and teeth.
After I regained consciousness and went back to bed, I convulsed and shivered for an hour. The combination of the beta blocker and the phenylephrine in Preparation H caused a life-threatening reaction. The cautionary statement is obscure and people who have used the product without problems are unlikely to look for the warning.
A. Thank you for sharing your story. Interactions between beta-blockers like metoprolol and topical phenylephrine (a vasoconstrictor in Preparation H) can be hazardous.
Here is what was discovered in a study published in the journal Clinical Pharmacology and Therapeutics (July, 1984):
“Patients on beta-blockers may experience a potentially harmful blood pressure rise after topical alpha-adrenoceptors such as phenylephrine. The presumed mechanism for this enhanced pressor responsiveness is unopposed alpha-adrenoceptor activity.”
That’s fairly complex pharmacology. The bottom line is that blood pressure can go up and heart rate can go down when a vasoconstrictor like phenylephrine (PE found in Prep H) is added to a beta blocker like metoprolol or propranolol. Paradoxically, this might reduce blood flow to the brain and lead to fainting. Thank you for warning others about this potential interaction.
Another Case of Prep H and BP Problems:
Most people never consider anal absorption when using a topical medication. Here’s another example, though:
Q. I used Preparation H twice yesterday and once today. I noticed a headache yesterday and attributed it to a lack of sleep.
When I applied the Prep H today, my headache returned. I checked my blood pressure and it was 16 points higher than normal. My typical BP reading with meds is 117/78. A diastolic reading of 94 concerns me.
I understand that the problem with Preparation H is the phenylephrine. Do I need to avoid this medicine?
A. There was a time when Preparation H advertised its hemorrhoid remedy as having “oxygen action.” Bryan Cranston, of Breaking Bad fame, performed in a Prep H commercial back in the early 1980s. This classic video took our breath away.
You might enjoy the video too at this link. Here are his now classic lines:
“You expect a hemorrhoid medicine to relieve your pain and itch. But you get extra therapeutic relief with Preparation H. It helps speed relief to inflamed hemorrhoidal tissue with oxygen action. A special medicine in Preparation H accelerates the absorption of pure oxygen to help shrink swelling of inflamed hemorrhoidal tissue fast…When you choose a hemorrhoid medicine, remember, oxygen action is special with Preparation H.”
We’re not sure what the “oxygen action” was all about.
In an interview on The Tonight Show with Jimmy Fallon (Nov. 21, 2017), Bryan Cranston admitted that he didn’t know what “oxygen action” was either. You will have to wait till the end of the interview to learn about Bryan’s career as a shill for Preparation H. We think you will find his Preparation H discussion quite amusing at this link.
The Old Preparation H:
So, what was in Preparation H back in the good old days? The “all natural” ingredients that were advertised to help shrink the swelling of hemorrhoidal tissues, reduce inflammation and heal injured tissue were:
- An antiseptic (phenylmercuric nitrate)
- 2,000 units of “skin respiratory factor” obtained from “live yeast cell derivative” or LYCD
- 3% shark liver oil
The New Preparation H:
The FDA determined in its infinite wisdom that the live yeast cell derivative in old Preparation H belonged in its Category III:
“data insufficient to support effectiveness.”
As a result, the maker of Prep H changed the formula in the mid 1990s.
The active ingredients in Preparation H Hemorrhoidal Ointment now include mineral oil, petrolatum (petroleum jelly) and phenylephrine. The phenylephrine (PE) constricts blood vessels. That is why it is also found in some decongestant nasal sprays. Bottom line, PE shrinks vascular tissue whether in the nose or the butt.
The instructions that come with Preparation H state:
“Ask a doctor before use if you have
- heart disease
- high blood pressure
- thyroid disease
- diabetes
- difficulty in urination due to enlargement of the prostate gland.”
“Ask a doctor or pharmacist before use if you are
- presently taking a prescription drug for high blood pressure or depression”
Anal Absorption of Phenylephrine?
People on blood pressure medication should generally avoid products containing vasoconstrictors like phenylephrine. That’s because anal absorption of a drug that constricts blood vessels does not just impact the nether region. Medications that are absorbed into the blood from this highly vascular area can circulate throughout the body and exert a systemic effect.
Reader Reports of Anal Absorption:
Another reader reported that using Preparation H for a week:
“…resulted in severely elevated blood pressure.”
Ray “almost broke” his doctor’s blood pressure monitor:
“The blood pressure increase happened to me. I went in for a normal check-up. I had used Preparation H that morning. I almost broke the blood pressure machine at my doctor’s office. They took my blood pressure three times to make sure the number was accurate.
“I was trying to think what I had taken to raise my blood pressure. Then I read the label on Preparation H and put 2 and 2 together. I came to this website and read your articles on Preparation H. It’s a good thing I am healthy. It makes you wonder how many people have been sent to the emergency room because they couldn’t handle this stuff. The warning should be more obvious.”
Oral Drugs To Avoid If You Have High Blood Pressure:
There are a number of medications to avoid if you have a tendency towards hypertension. All NSAIDs would be on the no-no list. That includes celecoxib, diclofenac, ibuprofen, meloxicam and naproxen. And stay away from natural black licorice. It too can raise blood pressure! Licorice can also deplete the body of potassium.
Learn More:
To learn more about measuring blood pressure correctly, drugs to avoid and strategies to control hypertension, you may wish to read our eGuide to Blood Pressure Solutions. This recently revised electronic resource is available in the Health eGuides section of www.PeoplesPharmacy.com.
Share your own experience with Preparation H. Did you ever use the original formula to fight wrinkles? What about to stop itching from scars? Add your comment below. And let us know what you think about Bryan Cranston’s Prep H commercial!
Did you learn something helpful from this article. Do you know anyone with high blood pressure? They might not confide that they also have hemorrhoids, but they should know about this interaction. Please share this article. They might also get a chuckle from the Preparation H commercial. Why not also encourage your contacts to sign up for our newsletter? They might find our tidbits as interesting as you do. Here’s a link.
