A new study has cautioned that zinc nasal gels and sprays used to find relief for common cold are not so effective in the first place, and worse they can cause users to lose their sense of smell.
Authors Terence Davidson and Wendy Smith of University of California, San Diego issued the warning after evaluating 25 patients and analysing reports of clinical, biological and experimental data.In addition to concerns regarding the efficacy of intranasal zinc therapy, increasing evidence indicates that this medication may be linked to severe, potentially permanent hyposmia (reduced sense of smell) and anosmia (loss of smell)," the authors said.
After the findings of the study, the authors requested the US Food and Drug Administration to more strictly regulate zinc cold therapies and other homeopathic remedies.
"Only homeopathic drugs offered for treatment of serious disease conditions' must be dispensed by a licensed practitioner," the authors said.
"Most over the counter nasal preparations are just for symptoms. Some people find it helpful for temporary relief of congestion, but it's not going to do anything in the long term," ABC Science quoted spokesperson for the Royal Australian College of General Practitioners, Dr. Ron McCoy, as saying.
He said that apart from highlighting the lack of benefit, the new study also highlights the need for consumers to be aware of the effects of complementary therapies.
"A lot of the marketing that goes on with some of these therapies is that they're natural," McCoy said.
"Its well recognised that many of the complementary therapies can interact with other medications and can have adverse effects. People need to know of these risks and benefits and need to talk about it with their doctor," he added.
The study appears in the American Medical Association's Archives of Otolaryngology.