Medication does not automatically mean safe. This is confirmed by health experts who warn that some common medications that can be purchased from pharmacies without a prescription may carry unexpected risks to health when used incorrectly or for long periods.
These warnings come at a time when there is increased reliance on readily available medications to treat simple symptoms such as pain or a cold, but this convenience may hide serious side effects if safe use is not observed.
Painkillers containing codeine
These medications are used to relieve mild to moderate pain, and may sometimes be added to treat cough. But the body converts codeine into a more potent compound, which increases the risk of drowsiness, dizziness, and breathing problems at high doses.
Over time, the body may develop a tolerance to the drug, which prompts some to increase the dose, with the risk of addiction and withdrawal symptoms when stopped suddenly.
People with ultra-rapid metabolism carry a genetic mutation that causes them to convert codeine into morphine much more quickly than normal. This trait is more common among people of North African, Middle Eastern, and Oceanic origins, and may lead to serious side effects even with standard doses.
To reduce these risks, it is recommended to use codeine for the shortest possible time. In the UK, the Medicines and Healthcare Products Regulatory Agency limits pack size to 32 tablets, and advises that over-the-counter products should be used for no more than three days.
Decongestants
Whether in the form of tablets or nasal sprays, these medications constrict blood vessels in the nose to relieve congestion. But prolonged use may lead to rebound congestion that makes symptoms worse from the beginning.
Overuse of nasal sprays may lead to rebound congestion, known medically as rhinitis medicamentosa. Over time, the effectiveness of the drug decreases, a phenomenon called pharmacological adaptation. This can trap people in a vicious cycle of increased use, worsening congestion, and drug dependence.
Pseudoephedrine is also known for its mild stimulant effects. Despite the mixed evidence on improving athletic performance, its stimulant properties make it on the list of substances banned in competitions. It is also used illegally in the manufacture of methamphetamine, which is why strict sales controls remain in place after a 2016 review.
Sleep medications
Promethazine and diphenhydramine, two sedating antihistamines, are sold as temporary sleep aids.
Recent research has linked sedating antihistamines to an increase in deaths, prompting calls for a review of the mechanism for their distribution.
The body’s tolerance to these medications leads to a decrease in their effectiveness over time, and may cause severe insomnia when trying to stop them, in addition to other risks when used incorrectly for sports or entertainment.
Cough syrup
Some cough syrups contain dextromethorphan (DXM), which can cause psychiatric symptoms when taken in high doses that resemble the effects of some psychoactive drugs.
Although it is safe when used as recommended, its misuse has raised concerns among health experts. When taken in high doses, it blocks NMDA receptors in the brain, which can cause dissociative effects similar to those of ketamine. Although it is safe when taken in recommended doses, its psychological effects have raised concerns about its misuse.
Laxatives
Many people misuse laxatives thinking that they help the body “cleanse” or lose weight. But incorrect use can cause dehydration, electrolyte imbalances, and long-term intestinal problems, and in some cases complications even lead to serious effects on the heart and kidneys.
Research suggests that stimulant laxatives do not inhibit calorie absorption, contrary to popular belief. Indeed, misuse may cause dehydration, electrolyte imbalance, and long-term damage to the intestines, with serious effects on the heart and kidneys in severe cases.
In 2020, the Medicines and Healthcare Products Regulatory Agency (MHRA) introduced new rules on pack sizes and warnings.
Experts stress that the availability of the drug without a prescription does not necessarily make it completely safe. Most of these medications are useful when used according to doses and directions, but excessive reliance on them or exceeding the recommended doses may cause real health harm.
Although regulators have taken steps in this regard, research indicates that their misuse continues. Its availability without a prescription does not necessarily mean that it is free of risks, and raising the level of awareness may contribute to preserving its benefit rather than its harm.