The tendency of insurance plans to use postal pharmacy services presents challenges that may not have received adequate attention. The effect of extreme temperatures on the stability of medication in transit and the placement of medications in unattended mailboxes (with potential for access by children) are concerns.

A 31-year-old woman presented with dry eyes, the Raynaud phenomenon, finger and facial numbness, and "blood clots" on her fingers. She had a history of thrombophlebitis and known protein C and protein S deficiency. Procardia 30XL (Pratt Pharmaceuticals, New York, New York), hypotears, and warfarin (revolving daily doses of 2.5, 2.5, and 5.0 mg) had controlled all symptoms for 6 months and maintained prothrombin time within the 1.5- to 2.0-s range. The following laboratory variables were normal: complete blood count, liver test results, kidney function, antinuclear antibodies, complement level, rheumatoid factor level, and results of cryoglobulin assays.

Although the patient's diet and over-the-counter medication were unchanged, her prothrombin time was now within seconds of control. The patient had no clinical or laboratory response to an increase in the warfarin dose to 5.0 mg/d.

Warfarin was then obtained from a local pharmacy and was begun at 2.5 mg every other day, alternating with 5.0 mg. This regimen restored the prothrombin time to within therapeutic range and relieved clinical symptoms. High-performance liquid chromatography with ultraviolet absorption of several of the patient's remaining 2.5-mg tablets showed mean warfarin levels of 2 ± 0.05 mg, values significantly less than specifications.

Because the mail-order pharmacy and manufacturer apparently have not responded to our request that they review storage and shipping procedures and alert their clients, the matter has been referred to the Food and Drug Administration.

Although one cannot extrapolate from a single case to an entire industry, the adequacy of mail-order pharmacy control may affect the hundreds or thousands of persons who receive drugs from that mail-order house. Physician and patient vigilance are especially essential when cost containment at least appears to supersede personal attention to quality care.