Monroe was found dead in the bedroom of her Los Angeles home on August 5, 1962, with a bottle of sleeping pills by her side.
Her death was ruled to be “acute barbiturate poisoning” and listed as “probable suicide” although investigators have since said it was more likely to have been accidental.
More recently, the deaths of celebrities such as Heath Ledger, Michael Jackson and Brittany Murphy have also all been linked to prescription drugs.
Although charities say that most cases they are aware of are using prescription drugs for a high rather than self-harm, there is concern that this abuse could be extremely damaging to their health and are highly addictive.
Martin Blakebrough, chief executive of Newport-based drugs support agency Kaleidoscope, said: “Even though they may be prescribed by GPs legally, prescription drugs can and are still a problem to many patients as they are often perceived to be safe.
“We try to make sure people have supervised consumption of these drugs but it’s not easy and people can be pretty creative if they want to get hold of them.
“One of the problems is that when you go to the GP you expect a prescription and I think GPs may sometimes be doing the easy thing by writing out a prescription. You look at people like Whitney Houston who was found with prescription drugs when she died. Doctors have a responsibility to say no to these people.
“It’s a complicated issue but things like antidepressants appear to be given out too easily when sometimes dealing with issues with drugs is not the answer.”
Statistics released in 2010 revealed a 73% rise in the number of men in Wales and England who had died as a result of drug poising involving benzodiazepines, with an 82% increase in women.
Janet Roberts, of Welsh drug helpline Dan 24/7, said: “In respect to the calls we get to the helpline people who are abusing prescription drugs seem to be buying them on the street.
“With drugs like valium or benzodiazepines, people may start by taking one a day, then think that’s not working so they will take two, and so on. For some of these people they then come into contact with groups of people like drug dealers who they never envisaged themselves with. They may just be desperate for some codeine but they are talking to the same people selling heroin.
“They are then have a big problem, but where do they go for help? They are unlikely to go back to their GPs, so it’s difficult to get support.”
Dr David Bailey, chairman of the BMA’s Welsh GP Committee, said although there were certain telltale signs in some patients, abuse of prescription drugs was a real issue faced by GPs.
He said: “Prescription drug abuse is a big issue for us as doctors with things like benzodiazepines always a cause for concern. Codeine is also one of the most used ones rather than anti-inflammatory drugs and ventolin is often used for people to get high which is difficult as it is prescribed for respiratory disease, which is quite prevalent in Wales.
“There are a lot of prescription drugs which can be abused. Things like sleeping pills are often sold on and tramadol and codeine have a street value. It’s something that we are always aware of. “You are always suspicious if someone come in and asks for certain drugs and GPs are aware of it 99% of the time. It’s quite difficult to prove that somebody is abusing drugs when they can act quite convincing. It can be very difficult to judge. GPs are more aware of these things, but people who abuse drugs can be imaginative and come up with lies to get a prescription.” Dr Bailey said more people are aware of the dangers of certain prescription drugs, which could be down to the link between them and high-profile deaths. He said: “I think people are generally more aware of the dangers of some drugs – especially things like tranquillisers but maybe less aware of codeine and tramadol. Some of these things that come out are getting prescribed far more than they should be. “High-profile deaths makes the general public more aware to some extent, however in Marilyn’s case, she took barbituates which you cannot really get now. ” In 2009, the All Party Parliamentary Drugs Misuse Group’s (APPDMG) published findings from its inquiry into dependence and addiction to over-the-counter and prescription drugs. The inquiry highlighted the addiction potential of prescription-only medicines such as benzodiazepines. It also raised concerns over the use of some painkillers, particularly those containing codeine, which are available without prescription. Drug charity Drugscope said the situation in 2009 is still the case today with more recent concerns centring around the abuse of online pharmacies. A spokesman for the charity said: “The MP report from 2009 highlighted the lack of specialist help for people who have problems with protracted use of especially the benzodiazepine tranquillisers on the basis of evidence from various support groups. There is no evidence that this situation has changed. “Overall it would seem that GPs are more aware these days of the dangers of unmonitored repeat prescriptions, but the numbers of prescriptions for drugs like anti-depressants is still high. There is nothing inherently wrong with these drugs, but the clinical guidelines on most tranquillisers and anti-depressants are clear that they are only for short-term use. “There are more recent concerns about prescription drugs outside of the context of legitimate prescriptions. It is clear that many people are taking advantage of online pharmacies where a range of drugs including powerful painkillers are available without prescription or proper medical advice.”