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Cough and Cold Medications |   |
| The number of medications available for dealing with the common cold and the coughs that accompany it is mind-boggling. Between the host of over-the-counter medications and those requiring a prescription, there is enough information to warrant a separate CEU. In this unit we will only discuss the most significant cough suppressants and expectorants. The medications that work centrally are designed to increase the cough threshold in the medullary cough center. Peripherally active medications inhibit the cough at the mucosa, usually by coating supraglottic receptors with a thick syrup. |  |
Expectorants are agents that facilitate removal of mucus from the lower respiratory tract, and their mechanisms include:
- vagal gastric reflex stimulation
- absorption into respiratory glands to directly increase mucus production
- topical stimulation with inhaled volatile agents
Super Saturated Potassium Iodide (SSKI) is available under a variety of trade names, and has been used for quite a long time as an expectorant in asthma and chronic bronchitis. In sufficient orally administrated concentrations, it has a direct mucolytic effect, and an indirect effect on mucus vicosity by stimulating submucosal glands to produce more serous secretions. Iodide also stimulates the gastropulmonary reflex, can stimulate ciliary activity, and has a cucolytic effect. In some individuals, iodides are associated with hypersensitivity reactions.
Five to ten drops (3-600 mg) in a glass of water given 34 times a day may be given, with the pediatric dosage being about half that amount. Patients can develop acne or rashes and long term use may disrupt thyroid function. SSKI is contraindicated for patients with thyroid disease.
Guaifenesin (Glycerol Guaicolate), available in a variety of trade name products, is thought to reduce the adhesiveness and surface tension of mucus secretions when taken orally. Dosage for children 6-12 years old is 2-400 mg every 4 hours with a maximum of 2,400 mg in 24 hours. Dosage for children 2-6 years old, half of this may be given, and for even younger children, half again (50-100 mg every 4 hours).
Iodinated Glycerol (Organidin) is available as a tablet, solution, or elixir. The adult dose of the 5% solution is 20 drops in a liquid QID. The 30 mg tablet dose is 2 tablets QID. The 1.2% elixir dose is 1 teaspoon QID. Pediatric dose is one half the adult dose.
Chicken soup, flavored with garlic and curry has been suggested as a tasty and effective stimulant via the gastric reflex. Garlic's major constituent is alliin, which has a structure similar to mucolytic drug S-carboxymethylcysteine. Other spices that could have similar potential include Tabasco sauce, horseradish, and mustard.
Codeine sulfate is a popular ingredient in variety of brand name cough suppressants. Compared to morphine, it is less addictive, has much less respiratory depressant activity, and is much less likely to cause bronchospasm or constipation. In doses below 15 mg, codeine does not produce analgesia in adults, with doses in the 10-20 range there is an antitussive action, and doses above 30 mg, codeine produces analgesia. Dosage is 10-20 mg every 4-6 hours, not to exceed 120 mg in 24 hours. For children 6-12 years old, dosage is 2.5-5 mg every 4-6 hours.
Benzonatate (Tassalon) is a nonnarcotic that has a local anesthetic effect with topical application. It acts on the sensory vagal receptors in the upper airway, and is though to inhibit the transmission of the afferent (cough and gag) impulse to the motor nerves through the medulla.
Dextromethorphan hydrobromide is a popular nonnarcotic antitussive that is available in a variety of brand name products, and is popular because it has no analgesic, respiratory depression, or addictive properties. Cough suppression is comparable to codeine. Dosage is 10-30 mg Q 4-8 hours up to a maximum of 120 mg in 24 hours. For children 6-12 years old, dosage is 5-10 mg Q 4 hours. For children 2-5 years old, dosage is 2.5-7.5 mg Q 4-8 hours.
Diphenhydramine hydrochloride, available in a host of brand name products (including Benadryl, Sominex, and Maximum Strength Nytol), is an antihistamine with antitussive properties, and is available in tablets, capsules elixirs, injections, lotions, and syrups. It can cause sedation and has anticholinergic effects. Adult dosage PO is 25-50 mg Q 4 hours, not to exceed 400 mg/day, and pediatric dosage is one-half that.
Hydrocodone (Hycodan Syrup) produces an antitussive effect with a dose of approximately 5 mg. However, it is an addictive derivative of opium, more potent than codeine, and can cause respiratory depression.
While there is still no cure for the common cold, that hasn't stopped pharmaceutical companies from producing a bewildering number of compounds that purport to treat and even cure colds. The ingredients in these cold remedies include: adrenergics, antihistamines, expectorants, and antitussives. Since most of these remedies are available over-the-counter, there is a very real potential for overdosing. Patients need to be cautioned that just because no prescription is needed, that doesn't mean the compounds are not both powerful and potentially hazardous to their health.