- Asthma Slideshow Pictures
- Take the Asthma Quiz!
- Asthma Myths and Facts
- Patient Comments: Asthma: OTC Treatment - Diagnosis
- Patient Comments: Asthma: OTC Treatment - Side Effects
- Find a local Asthma & Allergy Specialist in your town
- Asthma introduction
- What is asthma?
- What medications are used to treat asthma?
- How do over-the-counter (OTC) medicines for asthma work?
- What factors should be considered in choosing and using OTC epinephrine or ephedrine?
- What side effects and drug interactions are there with OTC asthma medicines?
- What are additional measures in the management of asthma?
Quick GuideAsthma Symptoms, Causes, and Medications
What side effects and drug interactions are there with OTC asthma medicines?
Ephedrine poses a greater risk of causing adverse drug effects or drug interactions than epinephrine because it must be absorbed into the body to be effective. Nervousness, sleeplessness, anxiety, nausea, reduced appetite, rapid heartbeat, tremors (the "shakes"), and urinary retention are the most common adverse effects. Immediate medical attention may be necessary for these side effects.
Monoamine oxidase inhibitors (phenelzine, isocarboxazid), clonidine, selegiline, guanethidine, and ergotamines (ergotamine tartrate, dihydroergotamine mesylate) may increase blood pressure when used at the same time as ephedrine. Methyldopa or reserpine may reduce ephedrine levels in the blood and thereby lessen the effectiveness of ephedrine. Tricyclic antidepressants (desipramine, amitriptyline, doxepin, and imipramine) may block the effect of ephedrine. The carbonic anhydrase inhibitors acetazolamide and dichlorphenamide may increase ephedrine blood levels and the risk of side effects from ephedrine. Patients taking any medications should consult with their physician or pharmacist before starting OTC ephedrine.
Since epinephrine is inhaled directly into the lungs and little is absorbed into other organs of the body, there is less risk for side effects. Epinephrine may cause rapid heartbeat, irregular heart rhythms, high blood pressure, tremor, or anxiety.
Since there are specific risks with epinephrine or ephedrine in certain medical conditions, physician advice and supervision should be sought before taking epinephrine or ephedrine if there is heart disease (coronary artery disease, congestive heart failure, irregular heart rhythms), high blood pressure, thyroid disease, diabetes, or difficulty urinating due to enlargement of the prostate. In addition, patients should seek medical advice before taking ephedrine if they are already taking antidepressants.