Erythromycin

Erythromycin is a bacteriostatic antiobiotic so it wouldn’t be useful in an immuno-compromised patient. However, we could turn it from bacteriostatic into bacteriocidal by increasing the blood level concentration through intravenous administration.  Erythromycin comes in many different salt forms which we’ll look at now…

Erythromycin base is an oral tablet that is very poorly absorbed and doesn’t really get into the blood stream. In this case, we don’t care for it to get in the blood stream because we want it to work in the GI tract. This is useful the day before GI surgery because GI surgery is a very “dirty” surgery. Once you open up the intestine we risk bacteria going in places they weren’t before. We call this pre-operative bowel sterilization.

Erythromycin Stearate is the most commonly utilized one. It is well absorbed but a lot of patients complain because it hurts. Antibiotics are generally full of side effects on the GI side because it’s killing off the good bacteria. Erythromycin is not only killing the bacteria but also irritating to the GI lining.

Erythromycin Estolate doesn’t cause GI upset but it can cause damage to the liver so it is rarely used.

Erythromycin Gluceptate or Lactobionate are the ones given intravenously.  Antibiotics are sometimes given intramuscularly but this one is specifically, never allowed to be given intramuscularly because the pH is so basic that it will hurt tremendously.  This hurts even during intravenous administration when it’s diluted.

Recap

• Bacteriostatic
• Forms
  • Base: oral, poorly absorbed, useful for bowel sterilization prior to surgery
  • Stearate: well absorbed, causes GI upset
  • Estolate: well absorbed, little GI upset, but associated with cholestatic hepatitis
  • Gluceptate, Lactobionate: IV use, cannot give IM

Erythromycin Use

It’s used for treating respiratory, otitis and syphlis caused by gram positive cocci.

Penicillin allergy: In case someone has a penicillin allergy, erythromycin is used as an alternative.

Acne: When applied topically, erythromycin is useful for acne because most acne is caused by bacteria.

Legionnaire’s Disease: Thirty years ago we didn’t even know this organism, called Legionnella, existed. It took a long time to find the organism, get it to grow and identify it. We just didn’t know how to grow this organism.  We couldn’t grow it because it required a very special plate. A number of physicians were having a convention at the legionnaire’s convention when this first surfaced. The problem surfaced again, not in a hotel but a hospital in Los Angeles. It became such a problem that any immuno-compromised patient was coming down with this. After 46 people died from this organism, they had to shut down the hospital for sick people. This problem existed for many months until they could find where this organism was coming from.  Turns out that it was coming from the water table because there was a well. They had to replace all the piping, everything from the bathroom sinks to the shower heads to solve the problem.  This organism still exists and when we have a patient in the hospital and we can’t find out what the organism is, we give them erythromycin.

Recap

• Use
  • Penicillin allergy to gram positive cocci for treating respiratory, otitis and syphlis
  • Topical use for acne
  • Legionnaire’s Disease
• Side Effect
  • Significant GI Upset