Nasal decongestants purchased off the High Street have a very rare but potentially serious brain side effect that experts are currently evaluating.
Pseudoephedrine-containing products are being scrutinized because they might cause the blood vessels supplying the brain to constrict or spasm, thereby decreasing blood flow.
This could trigger seizures or even a stroke, which is a cause for concern.
Drug authorities emphasize that the likelihood of this occurring is incredibly low.
In addition to more widespread side effects like headache and dizziness, products already include warnings about the rare risks on the patient information leaflets that are included with the medications.
Anyone with questions about medication, according to experts, should speak with a doctor or pharmacist. All medications have potential side effects.
Pseudoephedrine is used to treat congestion in the nose. It comes in tablets, liquids, and sprays and is occasionally blended with other medications for allergies, colds, and coughs.
Through its impact on nasal blood vessels, the medication can assist in opening up blocked airways and easing stuffiness.
The UK-wide review for pseudoephedrine was started as a result of French regulators notifying the European Medicines Agency (EMA), which is also conducting a review, about some recent, unusual cases.
Experts will examine two disorders of the brain's blood vessels: reversible cerebral vasoconstriction syndrome (RCVS) and posterior reversible encephalopathy syndrome (PRES).
RCVS can result in sudden, excruciating thunderclap headaches that frequently return over the course of days or weeks.
Vision blurring, headaches, seizures, and confusion are all possible PRES symptoms.
The UK's Medicines and Healthcare Products Regulatory Agency (MHRA) has a program called the Yellow Card that allows people to report any alleged drug side effects.
One PRES case in which the patient recovered and one RCVS case in which the outcome was reported as unknown, according to the MHRA, are among the few recent reports it has received in this manner.
The safety of the general public is our top priority, so we constantly assess the safety of all medications to make sure that the advantages outweigh any risks.
"We are examining the evidence at hand. We will offer any additional guidance as necessary. .
"Please seek guidance from a healthcare professional if you have any questions about your medication. ".
When new risks are discovered, patients may worry, according to Prof. Claire Anderson, president of the Royal Pharmaceutical Society. It's right that the proper authorities look into them, and we're waiting to see how the EMA and MHRA reviews turn out.