The role of viruses in the etiology and pathogenesis of common cold

Prevention and Treatment of Influenza, Influenza-Like Illness, and Common Cold by Herbal, Complementary, and Natural Therapies

In recent years viral respiratory tract infections, especially influenza viruses, have had a major impact on communities worldwide as a result of unavailability of effective treatment or vaccine. The frequent alterations in the antigenic structures of respiratory viruses, particularly for RNA viruses, pose difficulties in production of effective vaccines. The unavailability of optimal medication and shortage of effective vaccines suggests the requirement for alternative natural therapies. Several herbal remedies were used for prevention and treatment viral respiratory illnesses. Among those that were found effective included maoto, licorice roots, antiwei, North American ginseng, berries, Echinacea, plants extracted carnosic acid, pomegranate, guava tea, and Bai Shao. There is scientific evidence regarding the effectiveness of several complementary therapies for colds. Oral zinc may reduce the length and severity of a cold. Taking vitamin C supplements on a regular basis only slightly reduces the length and severity of colds. Probiotics were found better than placebo in reducing the number episodes of acute upper respiratory tract infections, the rate of episodes of acute upper respiratory tract infection and reducing antibiotic use. Alkaline diets or drinks might have antiviral properties as in vitro studies demonstrated inactivation effect of alkaline medium on respiratory virus. Earthing might have a natural anti-inflammatory effect for human body. It is now accepted that an overwhelming inflammatory response is the cause of human deaths from avian H5N1 influenza infection. Earthing accelerates immune response following vaccination, as demonstrated by increases of gamma globulin concentration. No in vivo or clinical studies were found that investigate the role of alkalization or earthing on respiratory viral infections. Thus, future studies are recommended to reveal any potential curative effects.

The effectiveness of high dose zinc acetate lozenges on various common cold symptoms: a meta-analysis

BACKGROUND

A previous meta-analysis found that high dose zinc acetate lozenges reduced the duration of common colds by 42%, whereas low zinc doses had no effect. Lozenges are dissolved in the pharyngeal region, thus there might be some difference in the effect of zinc lozenges on the duration of respiratory symptoms in the pharyngeal region compared with the nasal region. The objective of this study was to determine whether zinc acetate lozenges have different effects on the duration of common cold symptoms originating from different anatomical regions.

METHODS

We analyzed three randomized trials on zinc acetate lozenges for the common cold administering zinc in doses of 80-92 mg/day. All three trials reported the effect of zinc on seven respiratory symptoms, and three systemic symptoms. We pooled the effects of zinc lozenges for each symptom and calculated point estimates and 95% confidence intervals (95% CI).

RESULTS

Zinc acetate lozenges shortened the duration of nasal discharge by 34% (95% CI: 17% to 51%), nasal congestion by 37% (15% to 58%), sneezing by 22% (-1% to 45%), scratchy throat by 33% (8% to 59%), sore throat by 18% (-10% to 46%), hoarseness by 43% (3% to 83%), and cough by 46% (28% to 64%). Zinc lozenges shortened the duration of muscle ache by 54% (18% to 89%), but there was no difference in the duration of headache and fever.

CONCLUSIONS

The effect of zinc acetate lozenges on cold symptoms may be associated with the local availability of zinc from the lozenges, with the levels being highest in the pharyngeal region. However our findings indicate that the effects of zinc ions are not limited to the pharyngeal region. There is no indication that the effect of zinc lozenges on nasal symptoms is less than the effect on the symptoms of the pharyngeal region, which is more exposed to released zinc ions. Given that the adverse effects of zinc in the three trials were minor, zinc acetate lozenges releasing zinc ions at doses of about 80 mg/day may be a useful treatment for the common cold, started within 24 hours, for a time period of less than two weeks.

Analgesic and Decongestant Efficacy of the Combination of Aspirin with Pseudoephedrine in Patients With Symptoms of Upper Respiratory Tract Infection

The study investigated the efficacy and safety of a combination therapy of 1,000 mg aspirin (ASA) and 60 mg pseudoephedrine (PSE) on the symptoms of pain (combined score for headache and sore throat) and nasal congestion in 833 patients with acute upper respiratory tract viral infection (URTI), over 4 hours after a single dose in the clinic and over 3 days with multiple doses at home. The study demonstrated that over 4 hours in the clinic the combination ASA plus PSE was superior to PSE or placebo for relief of pain symptoms measured subjectively with pain scores, and was superior to ASA or placebo for relief of nasal congestion as measured objectively with rhinomanometry and subjectively with congestion scores. After 3 days of treatment, ASA plus PSE was superior to PSE but not to placebo or ASA for global pain assessments, and ASA plus PSE was superior to ASA and placebo but not to PSE for congestion assessments. No unexpected adverse events occurred and no serious adverse events were attributed to study medicines. This study demonstrates that a combination therapy of ASA plus PSE provides safe and effective relief of both common cold pain related symptoms and nasal congestion.

A review on the mechanism of sore throat in tonsillitis

BACKGROUND

Sore throat is a common condition associated with acute upper respiratory tract infection, and recurrent episodes of infection may result in chronic tonsillitis. The current UK and USA guidelines for tonsillectomy use the incidence of sore throat episodes as an indication for surgery. However, the mechanism of sore throat is poorly described in the literature.

OBJECTIVES

This review will provide basic information for the clinician regarding: the causes, pathophysiology and neurophysiology of sore throat; the mechanism of inflammation; and the role of transient receptor potential ion channels as nociceptors involved in sore throat. The review will present new ideas on the mechanism of ice therapy as an analgesic for post-tonsillectomy pain, and the role of vanilloid and cold receptors.