Can Afrin (oxymetazoline) be used in patients with preeclampsia who are on magnesium sulfate?

From the Guidelines

Afrin (oxymetazoline) should generally be avoided in patients with preeclampsia who are on magnesium therapy. The combination could potentially increase the risk of hypertension, which is already a concern in preeclampsia. Oxymetazoline is a vasoconstrictor that can raise blood pressure, potentially counteracting the beneficial effects of magnesium sulfate, which is used to prevent seizures and manage blood pressure in preeclampsia 1.

Key Considerations

• The primary concern is avoiding anything that might exacerbate hypertension or interfere with the therapeutic effects of magnesium in preventing eclampsia.
• If nasal congestion requires treatment in a preeclamptic patient on magnesium, safer alternatives should be considered, such as saline nasal sprays or external nasal strips.
• These options provide symptomatic relief without the cardiovascular risks.
• If medication is absolutely necessary, consultation with both obstetric and pharmacy specialists is recommended to determine the safest option based on the patient's specific clinical situation, severity of preeclampsia, and current blood pressure control.

Management of Preeclampsia

• According to recent guidelines, magnesium sulfate is recommended for eclampsia treatment and prevention among women with severe preeclampsia 1.
• The management of preeclampsia involves close fetal and maternal monitoring, antihypertension medications, and magnesium sulfate 1.
• Women with preeclampsia should be assessed in hospital when first diagnosed, and some may be managed as outpatients once it is established that their condition is stable 1.

Treatment Options

• Acceptable agents for treating severe hypertension in pregnancy include oral nifedipine or intravenous labetalol or hydralazine 1.
• Antihypertensive drugs should be reduced or ceased if diastolic BP falls <80 mm Hg.
• Safer alternatives for treating nasal congestion in preeclamptic patients on magnesium include saline nasal sprays or external nasal strips.

From the Research

Magnesium Sulfate and Preeclampsia

• Magnesium sulfate is commonly used for the treatment of eclampsia and prophylaxis of eclampsia in patients with severe preeclampsia 2.
• The therapeutic level of magnesium is between 4.8 to 8.4 mg/dL, and overdose can be fatal 3.
• Studies have shown that serum magnesium levels in patients with preeclampsia treated with magnesium sulfate are usually within the therapeutic range 4.

Use of Afrin (Oxymetazoline) with Magnesium Sulfate

• There is no direct evidence on the use of Afrin (oxymetazoline) in patients with preeclampsia who are on magnesium sulfate.
• However, it is known that magnesium sulfate can cause maternal toxicity, including respiratory paralysis and cardiac arrest, if not carefully monitored 2, 5.
• The use of other medications, such as Afrin, may need to be carefully considered in patients with preeclampsia who are on magnesium sulfate, due to potential interactions or increased risk of toxicity.

Monitoring and Precautions

• Careful monitoring of patients with preeclampsia who are on magnesium sulfate is crucial to prevent toxicity 2, 5.
• Deep tendon reflexes, respiratory rate, urine output, and serum concentrations are commonly followed variables to monitor for toxicity 2.
• The agreement between deep tendon reflex assessment and serum Mg2+ concentration is slight, although not significant, and more vigilant monitoring should be considered, especially in high-risk women 5.