E) Trace Sheet Monitors

Three companies sell devices, which determine when each dose of medication is removed from multiple cavities in a package by having an electrically conductive “trace” in a frangible cover over each cavity. When the medication is removed the trace is broken. By periodically passing electric current through the traces, it is possible to determine when medication is removed from each cavity.  Figure 1 shows the general features of a trace sheet monitor.

You can obtain details regarding specific commercial devices by checking with the companies.

Certus International Inc.  www.certusintl.com

Cypak Inc. www.cypak.com

Information Mediary Inc. www.informationmediary.com

While these trace sheet monitors are attractive, they would pose significant problems if used to dispense anti-TB medications that are commonly used today, since one of the anti-TB medications used in the initial phases of therapy, ethambutol, is hygroscopic and needs to be protected against ambient moisture.

Moisture protection could be achieved by filling the cavities in the device with medication and sealing the cover over the cavities in a factory.  However, the dosage of medication ingested by the patient varies depending on the weight of the patient.  If the Global Drug Facility packages are used the number of pills would vary between 2 to 5 per day and would require four different packages of medication in the supply lines from the factory to the clinic. This would pose significant logistics problems.

To avoid these logistics problems the cavities could be filled in the clinic. However, it would be difficult to make sure that the cover was properly sealed to each cavity so as to prevent moisture from entering the cavities.

A second method of avoiding ambient moisture is described in the section Alternate Means of Avoiding Ambient Moisture.

A third probably less optimal method of avoiding ambient moisture would be to supply the caregiver with small flexible waterproof packages each containing two or three pills of the multiple drug combination used in the initial phase of therapy.  The caregiver could use different combinations of these two packages to fill the cavities in the trace sheet monitor with 2, 3, 4, or 5 pills according to the weight of the patient.

For the continuation phase of therapy where ethambutol is not used and protection against moisture is probably not needed, the cavities could be filled with loose pills without preliminary packaging.

In the future ethambutol may be replaced with a drug that is not hygroscopic.  If this develops, trace sheet monitors could be filled in the clinic with loose pills and the trace sheet applied at that time. If such a non-hygroscopic regimen is developed, the trace sheet monitor may prove to be very effective.

TITLE PAGE and ABSTRACT

Background and Optimal Requirements for Medication Monitors for TB Treatment

I.   Cover and Cap Opening Monitors

II.  Dose Removal Monitors

III. Dose Removal Monitors Developed by Other Groups

     A) E-box

      B) U-box

IV. Devices That Prove or Come Close to Proving Medication Ingestion

V. Display incorporated into the monitor

VI. Means to instruct and remind the patient

VII. Retrieval of the adherence record

VIII. Retrieval of clinical data stored in the monitor

IX. Further notes on information retrieval

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Adapting to New International TB Treatment Standards with Medication Monitors and DOT given selectively