What medications can be administered intravenously (IV) but not intramuscularly (IM) to pregnant women?

From the Guidelines

Pregnant women should receive medications like labetalol, nicardipine, and nitroglycerin intravenously (IV) rather than intramuscularly (IM) due to the potential for tissue damage, pain, or necrosis associated with IM administration, as well as the need for precise dosing control that can only be achieved through IV administration. According to the most recent guidelines, including those from the European Society of Cardiology 1, IV administration is preferred for these medications to minimize maternal discomfort and tissue damage.

Some key medications that should be administered IV rather than IM in pregnant women include:

• Labetalol, which is considered safe and effective for IV treatment of severe pre-eclampsia 1
• Nicardipine, which can be used as an alternative to labetalol for IV treatment of severe hypertension in pregnancy 1
• Nitroglycerin, which is recommended for IV infusion in pre-eclampsia or eclampsia associated with pulmonary oedema 1
• Vasopressors like norepinephrine and epinephrine, which can cause local vasoconstriction and tissue necrosis if administered IM
• Certain antibiotics like vancomycin, which require precise dosing control that can only be achieved through IV administration

It's essential to establish IV access whenever possible to ensure safe delivery of the medication, appropriate dosing, and to minimize maternal discomfort and tissue damage. The most recent guidelines prioritize the use of IV administration for these medications to optimize outcomes for pregnant women 1.

From the Research

Medications for Pregnant Women

• The following medications can be administered intravenously (IV) but not intramuscularly (IM) to pregnant women:
  • Magnesium sulfate: This medication is commonly used to treat eclampsia and pre-eclampsia in pregnant women 2, 3. It can be administered IV, but not IM, due to its pharmacokinetic properties and potential toxicity.
  • Oxytocin: While oxytocin can be administered both IV and IM, the IV route is preferred for prophylactic management of the third stage of labor due to its lower risk of postpartum hemorrhage and blood transfusion 4.
• Other medications that can be administered IV to pregnant women include:
  • Hydralazine: This medication is used to lower blood pressure in pregnant women with hypertension 5.
  • Isoniazid, rifampicin, ethambutol, and pyrazinamide: These medications are used to treat tuberculosis in pregnant women and have an excellent safety record 6.
• It is essential to note that the administration of medications to pregnant women should be done under the guidance of a healthcare professional, taking into account the potential risks and benefits to both the mother and the fetus.

Administration Routes

• IV administration is preferred for certain medications, such as magnesium sulfate and oxytocin, due to their pharmacokinetic properties and potential toxicity.
• IM administration is not recommended for certain medications, such as magnesium sulfate, due to its potential toxicity and pharmacokinetic properties.
• The choice of administration route depends on the specific medication, the condition being treated, and the individual patient's needs.

Safety Considerations

• Medications administered to pregnant women should be carefully monitored for potential side effects and toxicity.
• Healthcare professionals should be aware of the potential risks and benefits of each medication and administration route.
• Patients should be closely monitored and treated promptly if any adverse effects occur.