Safe Antitussive Medications in the Second Trimester
Dextromethorphan is the safest and most appropriate antitussive for use during the second trimester of pregnancy, with extensive human safety data showing no increased risk of major malformations above baseline rates.
Primary Recommendation: Dextromethorphan
- Dextromethorphan is the preferred antitussive agent throughout pregnancy, including the second trimester, based on controlled human studies demonstrating safety. 1
- A prospective controlled study of 184 pregnant women (128 exposed in first trimester) found only 2.3% major malformations with dextromethorphan use—within the expected baseline rate of 1-3% for the general population. 1
- The mean birth weight (3,381g) and malformation rates were comparable to matched controls who did not use dextromethorphan. 1
- Dextromethorphan has over 30 years of clinical experience with a reassuring safety profile showing infrequent and usually non-severe adverse reactions. 2
Alternative Option: Codeine (Use with Caution)
- Codeine-based antitussives can be considered for second trimester use when dextromethorphan is ineffective, though they carry theoretical opioid-related risks. 3
- Codeine is often combined with first-generation antihistamines like chlorpheniramine for effective symptomatic relief of dry cough. 3
- While codeine has been used during pregnancy, all opioids carry risks and should only be used when absolutely necessary, with other options having better-established safety profiles preferred. 4
Clinical Context: Treating vs. Not Treating
- It is safer for pregnant women to receive appropriate treatment for respiratory symptoms than to leave conditions untreated, as maternal hypoxia and uncontrolled disease pose greater fetal risks. 5
- Misconceptions and suboptimal treatment of the mother may be more harmful to the unborn child than appropriate medication use. 6
- The second trimester is generally considered safer for medication use than the first trimester, when teratogenic risk is highest. 7
Medications to Avoid
- Avoid selective COX-2 inhibitors entirely during pregnancy, as they are contraindicated. 6
- NSAIDs can be used cautiously for short periods (7-10 days) in the second trimester if needed for other indications, but must be discontinued by gestational week 28 (end of second trimester) to prevent premature ductus arteriosus closure. 5, 8
Practical Prescribing Approach
- Start with dextromethorphan as first-line antitussive therapy in the second trimester. 1
- If cough is disturbing sleep, consider adding a first-generation antihistamine like chlorpheniramine, which provides sedation and has been used safely during pregnancy. 6, 3
- Ensure the patient understands that treating symptomatic cough is appropriate and safer than leaving respiratory symptoms uncontrolled. 5
- Document informed consent for medication use during pregnancy as part of optimal medical practice. 9