Dr. Rose's Peripheral Brain--THE COMMON COLD

THE COMMON COLD

I. Prevention

Probiotics
1. In a study in 326 healthy 3-5yo pts randomized to (lactobacillus acidophilus) vs. (L. acidophilus + Bifidobacterium animalis) vs. placebo BID x 6mos, both probiotic recipients had sig. lower incidence of fever (RR with both treatments 0.25), cough (RR with both treatments 0.35), and rhinorrhea (RR with both treatments 0.38) (Pediatrics 124:e172, 2009-JW)
2. In a systematic review of 14 randomized trials, probiotics did not conclusively reduce incidence of respiratory infections, but did reduce severity and duration (J. Antimicrobial Agents 34:???, 2009-Vouloumanou was the primary author)

II. Treatment

Zinc
1. Mechanism of action unclear; Has some non-selective antiviral activity in vitro; no studies have shown inhibited growth or shedding of rhinovirus in vivo
2. RDA is 15mg
3. Clinical studies
  1. Zinc gluconate lozenges (13.3mg elemental Zn Q2h while awake) vs. placebo in 100pts with common cold, begun within first 24h of sx, showed sig. reduction in duration of sx (4.4 vs. 7.6d) and fewer days of HA, hoarseness, nasal congestion, sore throat. No diff. in resolution of fever, myalgia, scratchy throat, or sneezing. Side f/x > placebo were nausea and bad taste. (Ann. Int. Med 125:81, 1996)
  2. Other studies using 23mg Zn per lozenge on similar schedule: 3 showed positive effect; three showed no effect (Med. Letter 39:9, 1997)
  3. A meta-analysis of 6 controlled trials; OR for incidence of any URI sx at 1wk in pts using Zn gluconate Q2h was 0.5 (but 95% CI 0.19-1.29; Arch. Int. Med 157:2373, 1997--JW)
  4. 249 schoolkids randomized to Zinc 10mg vs. placebo 5-6x/d for common cold; no sig. diff in duration of cold sx but more side f/x w/Zn (bad taste, nausea, diarrhea, throat irritation) (JAMA 279:1962, 1998--JW)
  5. In a study which randomized 273 adults with artificially induced colds (through challenge w/lab rhinovirus) and 291 with community-acquired colds randomized to Zn gluconate lozenges Q2-3h vs. placebo, the artificial-cold gorup had sig. reduction in duration of sx (2.5d vs. 3.5d) but the community-acquired group had no diff. in any outcomes measured with Zn vs. placebo (Clin. Inf. Dis. 31:1202, 2000--JW)
  6. 160 adults with URI at < 24h post-onset randomized to Zinc sulfate 0.12% nasal spray vs. placebo spray (2 sprays each nostril QID for up to 14d); no diff. in 2 groups in sx severity scores or duartion of sx (Am. J. Med. 111:103, 2001--JW)
  7. 48 pts with cold sx X < 24h randomized to zinc lozenges (12.8mg Q2-3h while awake) vs. placebo; average duration of cold sx were sig. lower in zinc group (4.5d vs. 8.1d) (Ann. Int. Med. 133:245, 2000--AFP)
4. Possible adverse effects (source: Med Letter 39:9, 1997)
  1. Nausea and unpleasant taste (see above)
  2. Some reports of decreased PMN and lymphocyte counts in healthy pts on 150mg BID x 6wks)
  3. 1977 case report of 3 cases of premature birth and 1 of stillbirth in women taking 100mg TID during 3rd trimester
  4. Zn Sulfate 600mg/d has been ass'd with induction of copper deficiency leading to anemia and neutropenia
Intranasal Corticosteroids
1. In a study in 981 pts with acute uncomplicated "rhinosinusitis" (7-28d of nasal congestion, nasal drainage, sinus headache, and facial pain or pressure, and no high fever or unilateral facial pain) randomized to mometasone furoate 200 micrograms intranasal QD-BID x 15d vs. amoxicillin 500mg PO TID x 10d vs. placebo, both mometasone groups had sig. greater symptom improvement c/w placebo but there was no diff. between amoxicillin group and placebo (J. All. Clin. Immunol. 116:1289, 2005--JW)
Systemic corticosteroids for pain relief in viral pharyngitis--See section on Group A Streptococcus for details
Antivirals
1. 2,096 pts with cold sx of < 24h duration randomized to plecornaril 400mg TID x 5d vs. placebo; plecornaril had sig. shorter duration of cold sx (6.3d vs. 7.3d with placebo) and reduced sx severity. (Clin. Inf. Dis. 36:1523, 2003--AFP)
Echinacea (click on link for details)