On Topical Penicillin

This afternoon I was convinced by my mother to allow a manicurist to work on my ugly toenails. And since these toenails of mine have not been seen by a professional in a year or so, the ill-fated manicurist had to contend against what was probably the largest, deepest, and ugliest ingrown cuticle she had to remove in her entire career (judging from the old woman’s routine, she’s been at it for a long time). Her experience and agility was unfortunately not enough against this monster of an ingrown that I had been allowing to thrive in the corner my right big toe: I was injured as she was trying to extract it (the monster of course was resisting death). We both gasped at the sight of blood, but what happened next was very interesting.

First she comforted me and told me that everything was fine, that sometimes these things happen, and that everything was under control (hmmm… familiar lines of medical interns missing IV insertions). Then she wiped away the blood with a cotton ball, which she followed with antisepsis using alcohol (OK so far). From her kit she then took a packet of what I later found out to be ground penicillin tablets; this preparation was carefully topically applied onto the side of the nail (where presumably the wound was). Her home instructions were to not allow the toe to get wet, as it would wash away “the medicine.”

It wasn’t my first time to encounter this strange belief that topical penicillin works on wounds. In Batangas, where I had my Community Medicine immersion, there was a man who, prior to consulting with us at the Barangay Health Center, already made budbod ground penicillin over a puncture wound (he accidentally stepped on a nail). It was my first time though to experience being the subject of the practice. The manicurist on the other hand tells me that this has been her routine ever since she started cutting nails (or more appropriately, ever since she started injuring people?); she swears by its effectivity.

Pharmacology teaches us that tablet preparations have to be activated by enzymes and juices in the stomach for them to take effect. There are topically-applied antibiotics (like mupirocin or tobramycin), but these are special preparations (gel, cream) and I doubt that they are produced simply by grinding the tablet forms of these drugs and then mixing them with water and starch to make a gel equivalent.

Knowing however that in the crazy world of medicine anything can happen, I launched a Pubmed search using the search terms “penicillin” AND “topical application.” The query yielded around a hundred citations. Sorry to EBM OCs, but my ADHD prevented me both from browsing through all the pages and from refining my search. Instead, I settled with the following abstracts which I felt were somehow relevant to my question.

1: Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Dec;96(6):685-94.

The efficacy and safety of 50 mg penicillin G potassium troches for recurrent aphthous ulcers.

Kerr AR, Drexel CA, Spielman AI.

Bluestone Center for Clinical Research, New York University, New York, USA.

PURPOSE: To determine both the efficacy and safety of the topical application of 50 mg penicillin G potassium troches (Cankercillin) in the treatment of minor recurrent aphthous stomatitis (RAS). STUDY DESIGN: The investigation used a phase 2 double-blind, randomized placebo-controlled trial with a no-treatment arm. Subjects with minor aphthous ulcers of duration <48 hours were followed for 1 week. The primary endpoint for efficacy was time (days) to complete ulcer resolution, and the secondary endpoint was time (days) to complete pain relief. RESULTS: Thirty-one, 33, and 36 subjects were randomized to the active treatment, placebo, and no-treatment arms, respectively. Baseline findings were heterogeneous across arms. Subjects who received penicillin G treatment had complete ulcer healing and pain relief significantly earlier than those in the placebo and no-treatment arms. No allergic reactions were observed. CONCLUSIONS: Topical penicillin G, by mechanisms which remain unclear, reduces the time of healing and pain relief of minor aphthous ulcers with minimal safety concerns. Larger phase 3 studies are necessary to confirm these findings.

2: J Infect. 2003 Oct;47(3):203-9.

When should old therapies be abandoned? A modern look at old studies on topical ampicillin.

Charalambous C, Tryfonidis M, Swindell R, Lipsett AP.

Department of Surgery, Manchester Royal Infirmary, Manchester, M13 9WL, UK.

OBJECTIVE: We sought to determine whether topical ampicillin can reduce the rate of wound infections in clean contaminated surgical wounds (appendectomy, colorectal surgery). METHOD: All randomized controlled trials examining the use of topical ampicillin in appendectomy and colorectal surgery published in English were identified via a Medline, Advanced Medline, and Cochraine Controlled Trials Register search and a meta-analysis performed.Results. Topical ampicillin vs. no antibiotic prophylaxis in clean contaminated wounds significantly reduced surgical wound infection rates (Odds Ratio (OR)=0.084, 95% CI, 0.04-0.16, P<0.0001). Topical ampicillin vs. no antibiotic prophylaxis in contaminated wounds also reduced surgical wound infection (OR=0.262, 95% CI, 0.14-0.51, P<0.0001). Topical ampicillin combined with systemic antibiotics vs. systemic antibiotics alone did not reduce surgical wound infection rate (OR=0.927, 95% CI, 0.27-1.72, P=0.90). CONCLUSION: Topical ampicillin significantly reduces the rate of surgical wound infections in clean contaminated surgery. A significant but smaller effect is seen in appendectomies where the appendix is gangrenous or perforated. Topical ampicillin did not confer any additional benefit when systemic antibiotics are used. While ampicillin may no longer be an effective agent, topical application of antibiotics is effective.Summary. A meta-analysis of studies using topical ampicillin for the prevention of infection in clean contaminated wound suggests that topical ampicillin is effective, but no incremental benefit is seen with systemic antibiotics.

Needless to say, the journal search was quite disappointing (Should I be surprised? Don’t harass me, I’m so tamad today to really look for relevant journals… plus, I’m injured). There have been many studies recently that look into the antiseptic and wound healing properties of some herbs and plants (like Takip Kuhol, for example, I should know, I’m sort of doing a paper and a presentation on this for Dr Jimmy Galvez-Tan). Maybe someone should look into the efficacy of ground tablets for topical application as well. Reminder: when that paper is finally written, don’t forget to credit manicurists for the discovery.

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