Bangladeshi border police are continually on the lookout for smugglers of cough syrup crossing from India into Bangladesh with their contraband, often thousands of bottles, hidden in trucks and buses.
The situation is equally fraught on the Indian side of the border, especially in the states of Assam, Meghalaya and Tripura, although cough syrup is legal there but only by prescription.
In July, Indian police said they confiscated nearly 30,000 bottles of Phensedyl hidden in a large truck entering Agartala, a city of 360,000 people in the state of Tripura and less than 2 miles from the border with Bangladesh. Tripura shares two-thirds of its border with Bangladesh.
Police acted on a tip and found the bottles of syrup, worth nearly $32,000, hidden in bags of rice. The vehicle was bound for Bangladesh, police said.
In March Indian authorities seized 4,000 bottles of Phensedyl from the cargo hold of a private airline in Agartala. Police said it was a worrying sign that the smugglers are making enough money to bypass slower road transport.
Cough syrup is sought mainly by younger people as a substitute for alcohol and for its sedative qualities. The price can be around $2 in India but by the time it reaches the black market in Bangladesh it can be as high as $12 a bottle.
Phensedyl and other cough syrups are illegally taken into Tripura state with forged documents, M.K. Pal, deputy drugs controller Tripura, said at a recent U.N-sponsored conference in New Delhi on drug abuse in northeast India.
Since liquor is banned in Bangladesh, cough syrups are a popular alternative for alcohol. Phensedyl was abused previously because it contained codeine phosphate and hydrochloride ephedrine and promethazine, both addictive. The formula has changed but not the habit of abuse, Pal said.
Manufacturers of the syrups, including Piramal Healthcare and Pfizer, are aware of the misuse and have routine programs to help prevent it.
"We conduct retail campaigns at frequent intervals, generally in a quarterly cycle, to ensure that the medicine is dispensed only when the prescription is produced by patients" an executive with Piramal Healthcare, the maker of Phensedyl in India, said.
"Also, in specific zones like the northeast, supplies are dispatched only against orders. We are careful about monitoring the supplies."
Over the past seven years India has been constructing a 2,500-mile concrete and barbed-wire fence along the border with Bangladesh in an effort to thwart smugglers of all kinds of contraband, including weapons, and stop terrorist infiltrations.
Around 1,550 miles of the $1.2 billion project have been built.