The pharmaceutical industry invests in a range of technologies to preserve the environment of its products during shipping, but can do little to safeguard them once they have reached the distribution network
The new study, presented at CHEST 2004, the 70th annual international scientific assembly of the American College of Chest Physicians (ACCP), looked at the efficacy of the inhaled asthma medication formoterol after its pack was exposed to 150 degrees Farenheit for 4 hours.
The result? The product delivered less than half of its expected dosage and showed significant physical changes.
"Inhaled medications are calculated to deliver a specific dosage for each use. Extreme temperatures can affect medications in just a few hours, causing them to deliver inaccurate dosages, making the medications less effective," said the study's lead author Gregory Chu, of the Carl T Hayden Veterans Affairs Medical Centre and Banner Good Samaritan Medical Centre in Phoenix, US.
"For patients with respiratory conditions, who rely on their medications to relieve acute breathing difficulties, inaccurate medication dosage can lead to serious medical consequences."
The researchers tested the effects of heat on powder-filled formoterol capsules and its effects on drug delivery. After exposure to heat in their packaging, the formoterol capsules were removed and dispensed into a filter tube using the inhalation technique and device provided by the manufacturer. The weights of the filter tube pre- and postdispensation were obtained to calculate simulated drug delivery.
The results showed that filter weights of heated medications were less than half of those unexposed to heat, showing that a significantly less amount of the drug had been dispensed after it had been heated. In addition, capsules exposed to heat were grossly distorted in appearance and showed visible clumping.
"Mail-order prescriptions have become increasingly popular among patients in the last few years. However, many patients do not realise that most medications have storage requirements regarding exposure to excessive temperatures," said the study's co-author, Richard Robbins.
"We strongly advise that patients avoid exposing medications to the extreme heat found in mailboxes and car interiors and inspect all mail-order medications prior to consumption."
They note that asthma medications are not the only medications at risk when exposed to high environmental temperatures as might be encountered in Arizona on a summer day. Any situation that exposes a drug, particularly those with gelatin capsules or containing powder, to excessive temperatures may put a patient at risk for consuming altered medication.
In 2003, mail order represented an estimated 17 per cent of retail prescription drug sales in the US, totalling more than $35 billion in sales and an increase of more than 15 per cent from sales in 2002.
"With the increasing popularity of ordering medications by mail, retailers who fill prescriptions by mail must place additional focus on the proper packaging and shipping requirements for at-risk medications, according to Paul Kvale, president of the ACCP.
"It also is important for patients to review manufacturer storage directions to ensure that medications are not exposed to extreme temperatures, either inside or outside the home," he added.
The onus is on mail-order companies to ensure their packaging provides good thermal insulation, and there may be a need - at least for some medications - for on-pack technologies that would demonstrate to the patient if safe environmental parameters have been breached.
At the end of last year, the European Court of Justice ruled that Internet and mail-order distribution of prescription drugs should not be allowed in the EU, although it said to do likewise with over-the-counter medications would be in breach of EU law.
The ECoJ was ruling in the long-running suit brought by the Deutscher Apothekerverband, the German federation representing over 19,000 pharmacists, against Dutch on-line pharmacy 0800 DocMorris NV and Jacques Waterval, a pharmacist and legal representative of DocMorris.
Mail-order of prescription drugs is illegal in Germany, but allowed to a certain extent in some other European countries, notably the Netherlands and the UK.