A nurse is talking with a client about taking an expectorant to treat a cough

Belongia EA, Berg R, Liu K. A randomized trial of zinc nasal spray for the treatment of upper respiratory illness in adults. Am J Med. 2001;111(2):103-8.

Ben-Arye E, Dudai N, Eini A, Torem M, Schiff E, Rakover Y. Treatment of upper respiratory tract infections in primary care: a randomized study using aromatic herbs. Evid Based Complement Alternat Med. 2011;2011:690346.

Benich J, Carek P. Evaluation of the Patient with Chronic Cough. American Family Physician. 2012;84(8).

Broaddus, VC., Mason, RJ., Ernst, JD., King, TE., et al. Murray and Nadel's Textbook of Respiratory Medicine. Philadelphia, PA: Elsevier Saunders; 2016(1):497-514.

Chang AB, Glomb WB. Guidelines for evaluating chronic cough in pediatrics: ACCP evidence-based clinical practice guidelines. Chest. 2006;260S-83S.

Chihara S. Bope & Kellerman: Conn's Current Therapy 2013. 1st ed. Philadelphia, PA: Elsevier Saunders; 2012.

Cohen HA, Rozen J, Kristal H, et al. Effect of honey on nocturnal cough and sleep quality: a double-blind, randomized, placebo-controlled study. Pediatrics. 2012;130(3):465-71.

Cornere MM. Chronic cough: a respiratory viewpoint. Curr Opin Otolaryngol Head Neck Surg. 2013;21(6):530-4.

Dalal B, Geraci S. Office Management of the Patient with Chronic Cough. The American Journal of Medicine. 2011;124(3).

de Vrese M, Winkler P, Rautenberg P, Harder T, Noah C, Laue C, et al. Probiotic bacteria reduced duration and severity but not the incidence of common cold episodes in a double blind, randomized, controlled trial. Vaccine. 2006 Nov 10;24(44-46):6670-4.

Dudha M, Lehrman SG, Aronow WS, Butt A. Evaluation and management of cough. Compr Ther. 2009;35(1):9-17.

Eccles R. Menthol: effects on nasal sensation of airflow and the drive to breathe. Curr Allergy Asthma Rep. 2003;3(3):210-4.

Frank LG. The efficacy of Echinacea compound herbal tea preparation on the severity and duration of upper respiratory and flu symptoms: a randomized, double blind, placebo-controlled study. J Comp Alt Med. 2000;6(4):327-34.

Guo R, Pittler MH, Ernst E. Complementary medicine for treating or preventing influenza or influenza-like illness. Am J Med. 2007 Nov;120(11):923-9.e3. Review.

Hirt M, Nobel Sion, Barron E. Zinc nasal gel for the treatment of common cold symptoms: A double-blind, placebo-controlled trial. ENT J. 2000;79(10):778-80, 782.

Josling P. Preventing the common cold with a garlic supplement: a double blind, placebo-controlled survey. Adv Ther. 2001;18(4):189-93.

Kantar A, Bernardini R, Paravati F, Minasi D, Sacco O. Chronic cough in preschool children. Early Hum Dev. 2013;89 Suppl 3:S19-24.

Lindenmuth GF, Lindenmuth EB. The efficacy of echinacea compound herbal tea preparation on the severity and duration of upper respiratory and flu symptoms: a randomized, double-blind placebo-controlled study. J Altern Complement Med. 2000;6(4):327-34.

Mahady GB. Echinacea: recommendations for its use in prophylaxis and treatment of upper respiratory tract infections. Nutr Clin Care. 2001;4(4):199-208.

Maurer HR. Bromelain: biochemistry, pharmacology and medical use. Cell Mol Life Sci. 2001;58(9):1234-45.

Melchart D, Linde K, Fischer P, Kaesmayr J. Echinacea for preventing and treating the common cold. [Review]. Cochrane Database Syst Rev. 2000;(2):CD000530.

Mullholland S, Chang AB. Honey and lozenges for children with non-specific cough. Cochrane Database Syst Rev. 2009;(2):CD007523.

Natt RS, Earis JE, Swift AC. Chronic cough: a multidisciplinary approach. J Laryngol Otol. 2012;136(5):441-4.

Oduwole O, Meremikwu MM, Oyo-Ita A, Udoh EE. Honey for acute cough in children. Cochrane Database Syst Rev. 2014; 12:CD007094.

Paul IM, Beiler J, McMonagle A, Shaffer ML, Duda L, Berlin CM. Effect of honey, dextromethorphan, and no treatment on nocturnal cough and sleep quality for coughing children and their parents. Arch Pediatr Adolesc Med. 2007;161(12):1140-6.

Prasad AS, Fitzgerald JT, Bao B, Beck FW, Chandrasekar PH. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. 2000;133(4):245-52.

Raeessi MA, Aslani J, Raessi N, et al. Honey plus coffee versus systemic steroid in the treatment of persistent post-infectious cough: a randomised controlled trial. Prim Care Respir J. 2013;22(3):325-30.

Roxas M, Jurenka J. Colds and influenza: a review of diagnosis and conventional, botanical, and nutritional considerations. Altern Med Rev. 2007 Mar;12(1):25-48. Review.

Shadkam MN, Mozaffari-Khosravi H, Mozayan MR. A comparison of the effect of honey, dextromethorphan, and diphenhydramine on nightly cough and sleep quality in children and their parents. J Altern Complement Med. 2010 Jul;16(7):787-93.

Smith SM, Schroeder K, Fahey T. Over-the-counter (OTC) medications for acute cough in children and adults in community settings. Cochrane Database Syst Rev. 2014;11:CD001831.

Zanasi A, Mazzolini M, Tursi F, Morselli-Labate AM, Paccapelo A, Lecchi M. Homeopathic medicine for acute cough in upper respiratory tract infections and acute bronchitis: a randomized, double-blind, placebo-controlled trial. Pulm Pharmacol Ther. 2014 Feb;27(1):102-8.