Prescription Medicines (1)

What Is The Difference Between A Prescription Drug And An OTC Drug?

Over-the-counter (OTC) drugs can be bought at a pharmacy or supermarket without a prescription. Prescription drugs are for conditions that are more serious, or need precise dosage and intake instructions given by a health care professional.

In the UK, the NHS has a list of conditions that do not need prescriptions. To obtain these medications, one can simply approach the prescribing professional at a local pharmacy [1].

The NHS is limiting the unnecessary amount of prescriptions given due to budget concerns.

Common conditions that do not need prescriptions are:

  • Sore throat
  • Fever and flu
  • Burns (minor)
  • Indigestion or heartburn
  • Hay fever
  • Diarrhoea
  • Constipation
  • Dry eyes
  • Travel sickness

Some individuals get addicted to OTC drugs. The most abused OTC drugs are those containing codeine [2] and Dextromethorphan (DXM) [3].

If taken continuously for three days, drugs containing codeine can be addictive [2].

If there are concerns regarding OTC addiction, a source of help would be an addiction clinic such as Abbeycare Scotland.

Is it Illegal To Misuse Prescription Drugs?

Possessing prescribed drugs without a prescription is illegal in the UK.

Using prescription medicines in a non-medical manner is also illegal in the UK.

If a person is given prescriptions for medicines, he or she can only use these medicines as advised by a health care professional.

Penalty for possession of these drugs for non-medical use is up to 5 years in prison with no limit on the amount of fine imposed [4].

The most misused prescription drugs are:

  • Opioids/narcotics/painkillers such as Dilaudid, Vicodin, Percodan, and OxyContin
  • Benzodiazepines such as Valium and Xanax
  • Stimulants such as Ritalin and Adderall
  • Prescription grade Codeine

Prescription misuse can lead to addiction to prescription drugs. Some cases can also lead to overdose with lethal consequences [5].

How Long Does It Take To Flush Medication Out Of Your System?

The time taken depends on what kind of drug is taken, how much of it is taken and how long an individual has been taking it.

For psychoactive drugs (drugs that can change moods and consciousness), the following are to be considered:

  • For benzodiazepines such as diazepam (Valium or Xanax), the effects of the medicine wane within 2 to 4 days [6].
  • For Rohypnol® (Flunitrazepam) – half of the effect is gone within 18-26 hours, but it is not totally eliminated in the system a few more hours [7]
  • For Adderall® Concerta®, Ritalin®, which are prescribed stimulants, the effects are gone approximately 10 hours after swallowing (for adult individuals) [8].

With regards to medication prescribed to treat other diseases like high-blood pressure, high-cholesterol, diabetes, and acid reflux, consult other authoritative sources.

To know the specific time needed to flush these medicines out, it could be helpful to be familiar with the concept of “half-life” in medicine.

When a medication hits its “half-life”, it means that from this time on, it has half the power it has from the point it was most effective. After half-life, the effect of the drug gradually decreases [9].

Knowing the half-life of a particular medicine can help predict the approximate amount of time the total effect of the medicine will wear off.

Factors that affect how long a drug stays in the system are [10]:

  • The type of drug used – some medications have a longer half-life than others, while some stay in the system for a long time because they are metabolised slowly by the body
  • The amount used – consider the dosage taken
  • How long an individual has been taking the drug
  • Body weight – generally speaking, if a person has a lot of body fat, s/he could be less affected by the drug taken
  • Age – younger people and the elderly generally are generally more affected by strong medication
  • Being hydrated or dehydrated – being well hydrated makes drug elimination somewhat faster
  • Body’s metabolism – an important factor as it determines how long the liver and kidneys filter the chemicals out of the bloodstream

Because withdrawal from prescription drugs could be risky, many individuals prefer to consult an addiction clinic whilst undergoing the process.

Tips on flushing out medicine from the system:

  • Drink up to 64 oz. of water or clear liquids a day to help your liver and kidney filter the drugs
  • Engage in aerobic exercise to promote sweating
  • Eat foods rich in fibre such as porridge oats, brown rice, and wheat bread
  • Try green juices, green tea, and lemon water, all of which have natural detoxifying effects on the body

How Long Do Detox Symptoms Last?

The usual amount of time for detox symptoms to disappear is within three to ten days. This amount of time generally applies to opiate drugs [11].

Drug detox from prescription medicines depends on several factors, but in general, the timeline would be:

Day 1 to Day 3

Initial symptoms include flu-like symptoms, insomnia, and anxiety

Day 4 to 7

This is the time when detox symptoms peak. Expect:

  • Cravings for prescription drugs
  • Irritable mood
  • Persistent insomnia
  • Fever and chills
  • Abdominal cramps
  • Vomiting/nausea

Day 7 to 10

A management team should be able to assist an individual to transition from drug withdrawal to the therapeutic stage on intervention at this point.

Some facilities offer medication such as buprenorphine, methadone or naloxone to help relieve withdrawal symptoms.

Some individuals ask why buprenorphine, methadone or naloxone is used to treat opioid addiction, since these medications are in the same family as the prescription medicines they are addicted to.

These medications used in medical detox work because like the addictive substance, they bind with opioid receptors in the brain. The brain’s receptors are occupied with the substitute drug, preventing further ties with the unwanted drug.

When an individual takes buprenorphine, methadone or naloxone under supervised detox, he or s/he does not feel euphoria, only relief from prescription medication withdrawal.

Giving the substitute drug is a form of gradual weaning off prescription medication. The end goal is abstinence.

Usually, a rehab clinic will work with the patient to make a personalised treatment plan to treat prescription drug addiction [11].

Can You Detox While On Medication?

Individuals can safely take medication while on drug detox provided that they are cared for in a facility with good standards. In the UK, certification from CQC is considered the industry standard [12].

Professionals well-versed in professionally assisted detox will routinely screen individuals for the usage of other medications.

Drug interactions happen, and without proper guidance, the results could pose serious health risks.

There are many conditions that require the usage of medication even whilst in detox. These conditions include:

  • HIV
  • Liver disease
  • Alcohol dependence
  • Hepatitis
  • Staph infections
  • Tuberculosis

How Is Prescription Drug Misuse Prevented?

To prevent prescription drug misuse, open communication with a health care professional is important. The following information should be relayed:

  • Medical history – past diseases, current complaints
  • Current diseases
  • Other medications taken, even vitamin supplements
  • Eating and sleeping habits
  • Psychological concerns about taking medicines such as need for treatment, fears of drug dependency, concerns about side effects, etc.
  • Scheduling problems about taking medication

Note that some people are more at risk of prescription drug misuse. If the following are present, it could help to be extra aware:

  • Past or present addictions to other substances such as alcohol and cigarettes
  • Family history of alcoholism or drug use
  • Psychological problems such as anxiety and depression
  • Being in environments where drug use is an accepted norm
  • Easy access to prescription drugs

If one is parent, preventing the misuse of prescription drugs can be done by:

  • Being vigilant with the amount and type of prescription medicine available at home (know how many there are exactly).
  • Some teenagers get access to prescription medications because the medicines were prescribed to their parents. Safeguard these types of medication properly.
  • Dispose of unused medications in the right place. Most pharmacies are obliged to take back unwanted medicines from patients for disposal.
  • Frame talks about drugs as a health issue to remove the shame and stigma.
  • Talk about real-life examples of drug problems in a neutral tone. Instead of stigmatising an individual with a drug use problem, adopt a problem-solving approach or a humane approach.



  1.  National Health Service. (2018). Why can’t I get a prescription for an over-the-counter medicine? Available at:
  2.  Gil, N. (2018). Young, Female & Addicted To Legal Pills. Available at:
  3. National Institute on Drug Abuse. (2019). Commonly Abused Drugs Chart. Available at:
  4. United Kingdom Government. (2013). Drugs Penalties. Available at:
  5. National Institute on Drug Abuse. (2019). Misuse of Prescription Drugs. Available at:
  6. Federal Drug Administration. (2011). Valium. Available at:
  7. (2007). Rohypnol. Available at:
  8. Medical News Today. (2018). Adderal (amphetamine/dextroamphetamine). Available at:
  9. Smith, Y. (2016). What is the Half-Life of a Drug? Available at:
  10. (2019). How long do drugs stay in your system? Available at:
  11. Gupta, M. & Attia, F. (2019). Withdrawal Syndromes. National Center for Biotechnology Information. Available at:
  12. Care Quality Commission. (2019). Treatment and Rehabilitation. Available at:

About the author

Melany Heger

Registered Psychologist and Freelance Writer, Jinjin Melany passionately writes about mental health issues, addiction, eating disorders and parenting since 2015. Read more about Melany on LinkedIn. Content reviewed by Laura Morris (Clinical Lead).