Expectorants are ingredients that increase airway secretions. They do this by increasing the water content of secretions which decreases their stickiness, making them easier to cough up.
What are expectorants used for?
Expectorants aim to make coughing up mucus easier, they do not actually stop coughing. This is important because a productive cough should not be suppressed because it is the body's way of removing excess mucus, foreign particles, or microorganisms from the airways.
Expectorants also help to relieve chest congestion that occurs because of a cold, the flu, or allergies.
Guaifenesin is mostly used for the treatment of chesty, wet, productive or phlegmy coughs, which typically occur with a cold. It has also been used off-label to help improve fertility and sperm survival in women with hostile cervical mucus (see here for more information).
Potassium iodide has been used to increase the water content of secretions and improve breathing in people with conditions such as asthma, chronic bronchitis, or emphysema.
Research has shown that expectorants are not as effective as mucolytics when used to treat certain respiratory conditions such as COPD.
Expectorants will not treat an infection.
What are the differences between expectorants?
Although guaifenesin and potassium iodide both work by increasing respiratory tract secretions, there are differences in their likelihood of side effects.
Side effects are much more likely with potassium iodide, which is the potassium salt form of iodine. Iodine is a trace element, which means that it is only needed by the body in very small amounts, and all trace elements are toxic if consumed at too high a dose for too long a period.
Sometimes people call expectorants mucolytics and vice versa. Although both result in less viscous (sticky) mucus, mucolytics have a different way of working than expectorants, and that is by breaking down the bonds within the mucus, thinning it out. Medicines that have a mucolytic action and that are available in the U.S. include acetylcysteine inhalation and dornase alfa. Bromhexine is a mucolytic available internationally.
|
Generic name |
Brand name examples |
|
guaifenesin |
Mucinex, Xpect |
|
potassium iodide |
iOSTAT |
Are expectorants safe?
Guaifenesin is generally well tolerated, and no severe side effects have been reported when it has been taken at recommended dosages. Higher than recommended dosages have resulted in stomach upset and vomiting. Guaifenesin should not be given to children younger than 4.
Potassium iodide has been associated with thyroid problems, high potassium levels in the blood, and iodide poisoning. People who develop neck or throat swelling, chest pain, an irregular heart rate, muscle weakness, tingly in their extremities, a severe headache, an allergic reaction, or other unusual side effects should seek immediate medical advice.
It is important to note that even though expectorants have been in use for many years, few studies have been conducted that prove that they work.
For a complete list of severe side effects, please refer to the individual drug monographs.
What are the side effects of expectorants?
Guaifenesin is generally well tolerated at dosages recommended for use as an expectorant. Nausea and vomiting are the most commonly reported side effects; constipation, dizziness, headache, and rash are reported rarely.
Side effects that have been associated with potassium iodide use include:
- Confusion
- Excess salivation
- Fatigue
- Gastrointestinal effects (such as acid reflux, diarrhea, nausea, vomiting, and stomach pain)
- Irregular heartbeat
- Numbness, tingling, pain or weakness in the hands or feet
- A severe headache
- Skin sores
- Sore gums
- Taste disturbances (including a brassy or metallic taste in the mouth).
For a complete list of side effects, please refer to the individual drug monographs.
