In the pharmaceutical industry, Losartan Potassium (an Angiotensin II Receptor Blocker or ARB) is strictly classified under FDA Pregnancy Category D. As a pharmacist and manufacturer, I must state directly: Losartan is NOT safe during pregnancy.

At your WHO-GMP facility in Mumbai, this clinical contraindication is a critical “Technical Warning” for your cardiovascular portfolio. If a patient on Losartan becomes pregnant, the medication must be discontinued as soon as possible.

The Clinical Risk: Why it is Contraindicated

The use of drugs that act directly on the Renin-Angiotensin-Aldosterone System (RAAS), like Losartan, during the second and third trimesters is associated with severe fetal injury and even death.

• Fetal Renal Failure: Losartan can impair the development of the fetus’s kidneys, leading to a lack of amniotic fluid (Oligohydramnios).

• Developmental Abnormalities: This lack of fluid can result in fetal skull hypoplasia (underdeveloped skull), limb contractures, and lung hypoplasia (underdeveloped lungs).

• Neonatal Hypotension: Newborns exposed to Losartan in utero are at high risk for severe low blood pressure and kidney failure immediately after birth.

Mechanism: The RAAS Interference

Losartan works by blocking the $AT_{1}$ receptor, which is essential for normal fetal development.

System Blockade: While blocking Angiotensin II is beneficial for reducing high blood pressure in adults, in a developing fetus, this system is vital for maintaining renal blood flow and organ growth.

Placental Transfer: Losartan easily crosses the placental barrier, meaning the fetus receives a direct dose of the medication, disrupting its fragile hormonal balance.

The Pharmacist’s “Technical Warning”

• The “Immediate Cessation” Rule: Advise all female patients of childbearing age that if they plan to become pregnant or suspect they are pregnant, they must consult their physician immediately to switch to safer alternatives like Methyldopa or Labetalol.

• Lactation Caution: It is not known whether Losartan is excreted in human milk. Because of the potential for serious adverse reactions in the nursing infant, a decision should be made whether to discontinue nursing or discontinue the drug.

The Manufacturer’s Perspective: Technical & Export

From a production and B2B standpoint at your facility in Mumbai:

• The “Black Box” Requirement: For all export markets, especially the US and EU, your Losartan packaging must prominently display the Boxed Warning regarding fetal toxicity. Failure to include this can lead to massive regulatory penalties and product recalls.

• Market Opportunity: On your marketplace, you can offer Methyldopa 250/500mg as the “Pregnancy-Safe Alternative” for your cardiovascular buyers, positioning your firm as a medically responsible partner.

• Stability for Export: Losartan is stable but hygroscopic. Utilizing Alu-Alu blister packaging is essential for maintaining a 36-month shelf life in Zone IVb tropical regions.