Travel bosses have warned holidaymakers to beware of falling foul of foreign laws on everyday medicines.
Tracy Wilkinson was prescribed the painkiller for a back injury
The warning comes after British tourist Tracy Wilkinson spent seven weeks in jail in Dubai after codeine was found in her system.
Travel industry body Abta said it was up to holidaymakers to check local laws and customs concerning medicines, including non-prescription drugs which are legal in the UK.
Tracy Wilkinson was detained at an airport in the United Arab Emirates following a passport problem and tested positive for the painkiller codeine.
The mother-of-two spent seven weeks in jail, even though her GP confirmed he gave her the pills.
She was eventually acquitted and arrived back in the UK on Thursday.
The 44-year-old sports osteopath from Balcombe, West Sussex, could have been jailed for four years, if convicted.
In England, codeine is found in common, over-the-counter preparations, including cough syrups, tension headache tablets, and treatments to stop diarrhoea.
But the drug, which falls into the same drug family as heroin, is controlled in some countries because of its narcotic properties.
Codeine has been used since French chemist Pierre-Jean Robiquet discovered it in 1832, and although it can be extracted from opium it is more commonly produced from morphine.
Even its name reveals its origins as codeine comes from Kodeia, which is Greek for poppy head.
The Foreign Office website specifically names Vicks inhalers as one hazard for tourists in Japan because of strict anti-stimulant drugs laws - it warns that "customs officials may not be sympathetic to visitors who claim ignorance".
The active ingredient in the inhaler is 50mg of Levmetamfetamine - a nasal decongestant.
Travel experts warn that tough substance laws in some countries could even lead to alcohol-based perfume or deodorant being confiscated.
So an unsuspecting tourist could easily find themselves in difficulties abroad, the campaign group Fair Trials Abroad said.
The group which supported Mrs Wilkinson's case said the different attitudes to such substances across the world proved a danger to tourists. The campaign group's Stephen Jakobi said: "This is not just a British problem - it is a problem for all Western travellers."
'Common sense checks'
"This is a form of accidental criminality and it's dangerous.
"If you run laws that are unfriendly to tourists, you won't get a tourist trade.
"It needs thorough digging on a worldwide basis to find out where the problems are, and to make the world reasonably safe."
Abta said people should check the Foreign Office website, which lists local laws and customs such as the alcohol ban in Iran, before travelling.
Codeine is a derivative of opium and has narcotic properties
Abta Spokesman Sean Tipton said checks regarding all substances including prescription drugs were common sense.
But he said the harshness of Tracy Wilkinson's treatment was hard to explain and said: "What happened to this poor woman is very unusual.
"There are countries where substances regarded as legal in the UK are seen as intoxicants."
And he said in some cases even alcohol-based anti-perspirant might be confiscated
Tourists taking over-the-counter medicine are advised to check the Foreign Office website while guidance to travellers taking prescription drugs is to talk to their doctor before travelling.
"If a doctor provides a letter about a particular preparation, they will take a much more lenient attitude," Mr Tipton said.