Current and future therapeutic approaches to the common cold Exper. Rev.2003 R2 손재돈

Pathophysiology Rhinovirus : most common Transmission : hand contact, aerosol Hypothesis Cooling  upper airway vasoconstriction Inhibition defenses converting viral colonization Symtom is Host inflammatory response Develop 1~2 days, Peak 2~4 days Nasal obstruction/rhinorrhea/sore throat Malaise/headache/ low-grade fever 2~3 wks

Epidemiology Most common Acute illness in all ages Increase in medical resource Risk factors Stress/Day-care in preschool/smoking Protective factors Red wine/Day-care in early school Frequent cold in 2~3 ages Likely to 6/8/11/13 ages

Current diagnostic approaches Based on symtoms Recent study, assessing Common cold No definite predictive criteria Rhinovirus DNA in Nasal swab Useless in daily ER or Primary office

Current therapeutic approaches 1. Overview Common cold : medically important But, Cure is not very successful Misconception/Misprescription Many antiviral agents are few benefit Combine antiviral & anti-inflammatory Improve outcome Maximum benefit early Dx. & Tx.

3. Anticholinergics agents 2. Decongestants α-adrenergic agonist Pseudoephedrine(액티피드) /Phenylpropanolamine Nasal obstruction/rhinorrhea No evidence benefit after several days 3. Anticholinergics agents Ipratropium( atrovent, inhalation) Rhinorrhea/sneezing

4. Antihistamines 5. Cough medicines 1st Antihistamines, chlorpheniramine 페니라민 Sneezing. Rhinorrhea, cough 2nd, Antihistamines, loratadine 클라리틴 only histamine receptor affect Not pass BBB 5. Cough medicines Mucolytics : modest beneficial 이외에는 similar to placebo

6. Mast cell stabilizes 7. NSAID Sodium cromoglycate(클레신) inhibit ICAM-1 ICAM-1, receptor for rhinovirus No benefit in RCT 7. NSAID Ibuprofen(캐롤) Headache/sneezing/myalgia and cough Combination other drugs : more effect

8. Steam inhalation 9. Vitamin C Symptom relief, but no reduction shedding 9. Vitamin C Controversy Recommend : 100mg daily intake A study, 500mg*2/day in winter Significant reduction in the number of cold Faster recovery But, fail to duplicated in large group

10. Zinc 11. Echinacea Controversy similar to Vit.C called the Purple coneflowers popularly boost immune system in america 16 study, better than placebo

12. Antibiotics 13. Steroids Most patients want to antiBiotics ‘Probably effective but not routinely recommended’ Amoxicillin(오그멘틴)/azithromycin(지스로맥스)/erythromycin(에릭) No evidence benefit in placebo test 13. Steroids Not effective in common cold

14. Antiviral agents 241 studies, interferon and other agents No licensed effective for common cold Pleconaril, inhibit viral uncoating In RCT, 1 day reduction to placebo Symptom reduction 20% to placebo But, antiviral agents developing

15. Multivitamins & minerals Daily Vit. E & multivitamine-mineral diet in well-nourished people No favorable effect in Acute URI Another study in DM people Significantly fewer infection Subclinical deficiency in DM individuals

Vaccine development Ultimate goal Hampered factors Large variety of virus High rate of re-infection despite antigenic variation Extensive variability in viral coat proteins Variable efficacy in immunity state Potential pathogenicity in neonates

Optimal therapy Educating patients about illness Targeting most distress symptom Adequate rest/humidity/take warm fluid/ well-diet/elevate head of bed α-adrenergic agonist/anticholinergics/antihistamine Nasal obstruction/rhinorrhea NSAIDS or AAP : treat systemic symptom Vit C/Zinc/echinacea : controversial Antibiotics : No role in common cold Pleconaril : close to achive, not yet Multivitamine : In diabetes

Phamacoeconomics 20 million days missed works 22million days missed school 25$ billion dollars 25 million office visits/years

Factors likely to affect choice of therapy 1. Patient compliance Recurrent/several times daily > difficult Clinical environment less compliance compare to study 2. Drug interactions & adverse effects Decongestants poorly controlled hypertention -> Phenylopropanolamine take off d/t hemorrhagic stroke incidence raise Rebound nasal congestants

1st antihistamines NSAID Warm stream Vit C Zinc Echinacea Pleconaril Confusion Affect CNS system NSAID Renal impairment/GI bleeding/Aseptic meningitis Warm stream Burns/microrganism Vit C Diarrhea Zinc Nausea & 식욕저하 Echinacea Anaphylaxis Pleconaril GI disturbance/menstrual irregularity

Conclusions Symptomatic measures -> current mainstay Specific antiviral agent : not available Zinc/Vit C/echinacea : controversial Any agent start as soons as onset

Prescription 액티피드 클라리틴 캐롤 Betadine 가글