A 20 y/o airman is newly assigned to your unit from basic training. He’s interested in giving blood during the group’s upcoming blood drive. He asks you if he’s eligible since he ‘got a shot of something’ while at basic training.

As you inquire further and review his medical record, you see his entire squadron at basic training was inoculated with 1.2 million units of benzathine penicillin secondary to a diagnosed case of gram-positive cocci necrotizing fasciitis.

What’s your answer to the airman and the blood collection folks? Accept his blood donation or not? Why or why not?

SELECT  here for discussion

  **From an actual case**

No.

Benzathine penicillin [Bicillin LA®] is a very long acting dosage form of penicillin. You can probably think of it as a “depot” form. This dosage form of penicillin provides low and prolonged serum levels of penicillin for as long as 4 weeks. The attached graph (built with data from MICROmedex and the product insert) shows the serum levels vs. time. Our local blood donor center will not draw someone’s blood for 30 days after an injection with benzathine penicillin. The data form the attached graph shows a serum level of 0.003 unit/mL at 30 days post inoculation in adults with 1.2 million units of benzathine penicillin. The concern is if there’s penicillin in someone’s donated blood and that donated unit of blood is transfused to someone who is anaphylactically allergic to penicillin, you could precipitate a severe reaction. There doesn’t seem to be a magic threshold above which such a patient will always react and below which such a patient is safe. Very sensitive individuals can react to very small amounts of penicillin.

Benzathine penicillin has been used for several years for seasonal prophylaxis against group A strep outbreaks in our military training population between October and March. The benefit of such prophylaxis is the prevention of post-strep sequelae to include acute rheumatic fever, post-strep glomerulonephritis, necrotizing fasciitis, and toxic shock syndrome. In our active duty military population, we have fewer lost training days (a big deal here!). The cost to inoculate ~ 6,000 trainees with about $17,000 (Drug cost only using government drug prices). The ‘serious ADR’ rate (serious = requiring hospital admission) has been 0.022% or 2 out of 9,203 (from March 2000 data). Therate reported in the literature is between 0.04 and 0.004%.  Public health uses a “trigger” of ten cases per flight in initiate the prophylaxis, consistent with Army and Navy “trigger” rates. For patients allergic to PCN, the recommended regimen is erythromycin 250mg po BID for 30 days. Training instructors and trainees must ensure this regimen is complied with.
 

This Pearl is meant for academic and educational purposes only. This Pearl is meant to raise important points regarding the safe and cost-effective pharmacotherapy of patients. It is not meant to be the definitive reference for the treatment or prophylaxis of various diseases. Although every effort is taken to ensure this Pearl is correct and factual, errors may occur. The US Air Force, the 59th Medical Wing (MDW), and 59th MDW Pharmacy assume no liability for incorrect information or harm that may occur from the use of the information included in this Pearl.