Of course, we wouldn’t need to fret about caregivers’ susceptibility to airborne bacteria/endotoxins on the one hand, or aerosolized drugs on the other, if these contaminants were not allowed to access the bedside environment in the first place. Patients are routinely counseled against sharing their prescription drugs with friends or family members. We would be well advised to heed our own advice, by taking the requisite steps to prevent ourselves from inhaling the aerosolized drugs prescribed for our patients! Kacmarek and Kratohvil5described the employment of a double-walled scavenging system that can be used when administering ribavirin to nonintubated patients, and documented the effectiveness of that strategy. And in 1986 we published an article6detailing the methods that we had developed at Stanford University Medical Center, whereby ribavirin aerosol could be scrubbed from the expirate of patients receiving mechanical ventilation who are receiving that agent. This serves to protect the valve box of the ventilator, as well as any patients/caregivers who might happen to be in the vicinity of the machine, from being bombarded with ribavirin particles. Of course, caregivers’ concerns with respect to their incidental exposure to ribavirin aerosol has markedly abated in recent years, simply because that agent is now rarely, if ever, employed for the treatment of respiratory syncytial virus (H. Rodriguez, MD; personal communication; June 2002). However, aerosolized pentamidine isethionate continues to be a popular agent for the prophylaxis of Pneumocystis carinii pneumonia. In the outpatient clinics of our pediatric hospital, it is not unusual for us to administer four or more pentamidine treatments on a given day. We have modified the Respirgard (Marquest Medical Products; Englewood, CO), the nebulizer system that was expressly specified by the US Food and Drug Administration for the delivery of pentamidine aerosol, by interfacing it to an airtight soft-cushion mask. This modification allows us not only to contain pentamidine aerosol within the confines of the mask, but also to trap any tuberculosis droplet nuclei that might be generated secondary to aerosol-triggered coughing. This is an important factor to consider when dealing with patients who are immunocompromised, and might unwittingly harbor active tuberculosis. So-called “pentamidine booths” have been created to cope with this hazard, but having a toddler sit in an airtight booth that isolates the child from his/her parents is not a practical alternative. In a sense, the airtight, soft-cushion mask might be considered to be a “booth for the face.” When we tested the Respirgard circuit that had been modified in this manner, an unforeseen bonus was observed to emerge. Pentamidine deposition roughly doubled,7 owing to the fact that the mask apparently serves as a spacer or holding chamber. The Respirgard system, as supplied by the manufacturer, already incorporates a breathing circuit filter, the Marquest MQ-303. Admittedly, one’s ability to sequester particles, intended for the patient, within the circuit will be crucially linked to the competence of that filter. Unfortunately, one of our sharp-eyed RCPs noted that a faintly visible plume of pentamidine could be observed to traverse the MQ-303 filter during administration of that agent! For that reason, we require that our therapists mount an ultraefficient breathing circuit filter (Conserve 50; Pall Corporation; East Hills, NY) on the outlet of the MQ-303.4 Any reader who might be interested in learning the specifics of our methodology is invited to supply me with an e-mail address to which I will post an electronic file containing a thoroughly detailed slide show. This slide show, written as a portable document format (PDF) file, is readable using Adobe Acrobat Reader software (Adobe Systems Incorporated; San Jose, CA), which is itself downloadable, free of charge, from the Adobe Web site.