We are on a drug run. There are more than 20 people involved and there are potentially tens of thousands of dollars at stake. The border into the United States has to be crossed but we have been assured that we have nothing to fear from the customs officers. All we have to do is get on the bus and sit tight.
But this drug run from the Mexican border town of Nogales to Phoenix in Arizona is completely legal. The drugs being purchased are prescription drugs and there are even a couple of licensed American pharmacists on board to answer questions and give advice. This is the Prescription Express, a mobile symptom of a health crisis in the US where more than 40 million people have no medical insurance and the soaring cost of drugs means that some of them are now having to make a choice between taking their medication and eating.
The Prescription Express takes people who need medicinal drugs across the border into Mexico where the same drugs can cost a fraction of the price in the US. This is only the second fortnightly run from Phoenix but the enterprise's founder, Ron Swager, hopes that it will soon be running much more frequently. Interest in the idea is already intense from both would-be passengers and politicians. Those on board the bus have paid $25 (£17.50) for annual membership and a further $40 (£28) for the trip from Phoenix or $20 (£14) from Tucson. By the end of the day, some will have saved themselves as much as $800 (£570) in prescription charges.
Swager, a marketing man who was born in Connecticut but has made his home in Tucson, thought of the idea after hearing a pharmacist at a heart patients' support group he attends talking about how the cost of drugs was now so high that people were crossing into Canada to buy them.
"A lightbulb went on in my head," said Swager over breakfast in Tucson before the bus set off on the second leg of its journey. "I thought - why isn't anyone doing that here?" As a marketing man, he decided that he needed a "product differentiation". Hence the traveling pharmacist, who reassures passengers and gives free advice. South of the border, he found a Mexican pharmacist, Francisco Cervantes, who had a store away from the town center where the bus could park. "The coach provides safety and comfort," he said. "People can pay with a dollar check - they're not exposed to Mexico except for a 10ft walk."
Most of the drugs in Mexico are less than half the price in the US, some as little as a 10th. The drug companies charge whatever they think the local market will take which in the US leads to skyrocketing prices. This has left many unable to afford their basic medications.
The 60-mile trip through the Sonoran desert, past ranches and trailer parks, takes little more than a hour during which the pharmacists, Marty Wicker and Saul Rutin, stand in the bus aisle answering questions and cracking jokes. Those on board are mainly women, the oldest 91 but most in their 60s. Some younger people on board have come with their parents' prescriptions. The novels of Danielle Steele seem to be the favored travel reading.
"This is going to become very commonplace," said Rutin of the express. "Forty-one million people in this country do not have medical insurance. The cost of drugs is going up by 15-20% a year. We are talking about maintenance drugs - do they eat or or do they take their medication?"
The AARP, formerly known as the American Association of Retired Persons, which represents more than 30 million people over 50, say they believe the issue could become a key factor in the mid-term elections later this year. "It's really becoming a problem for more and more of our members," said spokesman Steve Hahn yesterday. "We hear from them about it all the time. Come November, it could be the major election issue."
In Nogales, up a winding street opposite a taco stall, Cervantes and four colleagues are waiting to serve the customers. He owns three other pharmacists in town and said 85% of his business is now from Americans crossing the border to save money.
"It's a political issue," said Merry - "as in Christmas" - Mohr, one of the passengers. "It's disgraceful that we have to be bussed to another country. I'm a 67-year-old widow of 20 years and my resources are limited. Our government should be looking at protecting our own citizens and letting Israel and the Palestinians take care of their own business. The government should be examining the enormous profits that the drug companies are making. It would be a good issue for the loyal opposition [the Democratic party] to get involved in."
"I wasn't born in the United States and one of the first things that struck me when I came here was how expensive health care was," said Ken Opara, who comes originally from Nigeria and had spent some time in England. He was buying medicine for his parents who have no health insurance. "I saved about $350 [£250] today."
Other passengers are just happy at the savings they have made. Warren Wampole, a 64-year-old retired local government employee, suffers from high blood pressure and arthritis and his insurance company has now set a limit on what they will pay for the drugs he needs. He emerges from the store carrying a large plastic bag with five different kinds of medication.
"I just figured it up," he said. "I saved $800 [£575]." Marsha Mizelle, a physiotherapist, was buying drugs for her mother and mother-in-law. "This trip saves about $320 [£225]. One day every three months is worth it to me."
Sue Horne, who has come down with her daughter to buy a number of drugs she needs, compares the prices. Her Prozac in the US would have cost her $84 (£60) for a month's supply but here she is paying only $57 (£41) for three months worth of its generic equivalent.
For some, the bus trip is about more than saving dollars. Susan Harris, who moved to Tucson from Colorado, said: "Of course, it's to save money but part of it is the adventure. Maybe being alone, it is a nice way to get here. We thought it would be a bunch of gray-haired old bats which is hasn't been. You have to be a little bit brave to sign up cold. I've probably saved $200 [£140] - it's kind of fun for a day's adventure."
"I'm enjoying myself," said Nancy Steward, a mental health worker from Phoenix who was buying a supply of Celebrex for migraine, something not covered by her insurance company. "It's a nice day, you see a different culture."
Once everyone has bought their drugs, the journey back across the border begins. Customs officers check the drugs bought against the prescriptions carried by the passengers. Swager said he does not allow any controlled substances in and that he screens out young people who might be looking for drugs for reasons other than medicinal.
He said the Prescription Express had already brought rewards that were not financial and that one cancer patient had saved herself $1,200 (£850) on a trip. "I've never had so many 'God-bless-yous' from people in my life," he said. "It's fulfilling."
Nogales is Pancho Villa country. He can hardly have imagined that one day the cross-border raids would be to do not with cattle rustling or raids but with the price of Klonapin and Glocophlage and that the ill people of Mexico's wealthy northern neighbors would be seeking help south of the border.
© Guardian Newspapers Limited 2002