Although the fruit-flavored or minty lozenges that you take when you feel a tickle in your throat look like candy, many contain ingredients that can affect more than just your cough. Some cough drops rely on pharmacological ingredients to quell a cough, while others use compounds that moisten a dry throat. Overconsuming any kind of medicine can have negative effects, including cough drops.
Why You Cough
As uncomfortable as it is, coughing serves a purpose. During a cough, your lungs compress and expel foreign substances and invading bacteria, ridding your body of these potential irritants. By itself, a cough isn't dangerous; suppressing a cough may make you sleep more comfortably, but it won't shorten or lessen the severity of the illness causing the cough. See your doctor if your cough brings up thick, heavy mucus or blood.
Active Ingredients in Cough Drops
Some cough drops soothe a sore throat with cooling mint or mild honey. They ease the discomfort of a cough without suppressing it. Others act as a delivery system for medications that reduce congestion or suppress the urge to cough, some of which have a direct influence on heart rate. Dextromethorphan, pseudoephedrine hydrochloride and ephedrine alleviate cold symptoms, but may also elevate your heart rate. Lidocaine, a topical anesthetic, may alter your heart rate if you consume too many cough drops containing it. Adhering to the manufacturer's directions when taking cough drops containing lidocaine.
In recommended doses, menthol is harmless. The website Medline Plus describes an elevated heart rate as one of the symptoms of menthol overdose. However, this description applies to pure menthol, not to menthol cough drops that contain only a small amount of the potent flavoring agent. While it's theoretically possible to eat enough cough drops to affect your heart, you would suffer indigestion well before you consumed enough menthol to affect your pulse rate. Follow package directions when taking any medication, even menthol cough drops. Your doctor or pharmacist can answer specific questions you have about the appropriate dosage of menthol cough drops.
Medications and Contraindications
Cough drops that contain dextromethorphan, pseudoephedrine hydrochloride or ephedrine may elevate your heart rate even at the recommended dosage. These medications can interact with other medications that you've taken, particularly if you recently took another over-the-counter cold and flu preparation. While it's important to read the ingredient panel for any medication that you take, some pharmacies store cough preparations containing ephedrine or dextromethorphan behind the counter. Consider their location an indication that these cough suppressants contain powerful medications that could affect your heart rate.