What as‑needed (PRN) medications for severe anxiety are safer than propranolol in a pregnant woman in her second trimester?

As-Needed Medications for Severe Anxiety in Second Trimester Pregnancy

For severe anxiety requiring PRN medication in the second trimester, there are no clearly safer alternatives to propranolol that are appropriate for as-needed use. The evidence shows propranolol is actually considered a relatively safe first-line agent during pregnancy, though it requires specific monitoring rather than avoidance 1.

Why Propranolol Remains Reasonable for PRN Anxiety

• Propranolol has a longer safety record compared to other beta-blockers and is considered relatively safe for chronic prophylaxis during pregnancy, though ideally avoided in the first trimester 1.
• The American Heart Association and American College of Cardiology suggest propranolol as a first-line agent, with the primary concern being intrauterine growth retardation (IUGR), particularly with first trimester exposure and longer duration of treatment 1, 2.
• Since you are already in the second trimester, the highest risk period for major malformations has passed 1.
• Using the lowest effective dose and titrating according to clinical response minimizes risk 1.

Alternative Medications and Their Limitations

Benzodiazepines (e.g., Lorazepam)

• Benzodiazepines are generally contraindicated for chronic use during pregnancy and should only be used occasionally after the first trimester if absolutely warranted 3.
• The FDA label for lorazepam explicitly states that "the use of lorazepam during this period [first trimester] should be avoided" and notes increased risk of congenital malformations with minor tranquilizers during early pregnancy 4.
• Chronic use of benzodiazepines during any phase of pregnancy is contraindicated 3.
• Neonatal withdrawal symptoms, hypoactivity, hypotonia, hypothermia, respiratory depression, apnea, and feeding problems have been reported in infants exposed late in pregnancy 4.
• While occasional use after the first trimester may be warranted for severe anxiety or insomnia, this is not clearly safer than propranolol 3.

SSRIs (Sertraline, Citalopram)

• SSRIs are not appropriate for PRN/as-needed use because they require daily dosing for 4-6 weeks to achieve therapeutic effect 5, 6.
• Sertraline and citalopram appear to be first-line choices within the SSRI class for ongoing treatment of anxiety and depression in pregnancy, with better safety profiles than paroxetine or fluoxetine 6.
• However, these are for chronic daily treatment, not PRN management of acute anxiety episodes 5.

Antihistamines

• Sedating antihistamines are sometimes used for anxiety but lack robust evidence for efficacy in severe anxiety and are not mentioned in pregnancy-specific anxiety treatment guidelines.

Required Monitoring with Propranolol

If continuing propranolol for PRN anxiety management in the second trimester:

• Serial ultrasound monitoring for fetal growth is recommended by the American Institute of Ultrasound in Medicine, as IUGR is the primary concern 1.
• Surveillance for fetal bradycardia throughout pregnancy is advised by the American College of Cardiology 1.
• Serial echocardiography during second and third trimesters when hemodynamic load is highest, per the American College of Obstetricians and Gynecologists 1.
• Monitor newborn for hypoglycemia and metabolic abnormalities after delivery, as recommended by the American Academy of Pediatrics 1.

Critical Pitfalls to Avoid

• Never use atenolol - it causes more pronounced IUGR than propranolol and should be completely avoided 1, 2.
• Avoid benzodiazepines during labor and the first week postpartum due to neonatal effects 3.
• Do not abruptly discontinue propranolol if it needs to be stopped 2.

Clinical Decision Algorithm

1. Assess severity and frequency of anxiety episodes: If truly requiring PRN medication rather than daily treatment, propranolol remains reasonable in the second trimester 1.

2. If anxiety is frequent enough to require regular medication: Consider switching to daily sertraline or citalopram rather than PRN propranolol, as untreated anxiety carries risks including premature birth and maternal distress 1, 6.

3. If propranolol is contraindicated (asthma, cardiac failure, Raynaud disease, atrioventricular block): Consider very occasional benzodiazepine use only after weighing risks, or transition to daily SSRI therapy 2, 3.

4. Implement non-pharmacological approaches first: Staying well hydrated, maintaining regular meals, securing sufficient sleep, appropriate physical activity, and identifying triggers 2.

The bottom line: There is no clearly superior PRN medication for severe anxiety in the second trimester compared to propranolol, which has established safety data when used at the lowest effective dose with appropriate fetal monitoring 1, 2.