Intrauterine Drug Delivery Systems (IUDs): Overview

• Intrauterine Drug Delivery Systems (IUDs) are devices placed in the uterus for localized drug delivery.

• Primarily used as contraceptives, they deliver drugs directly to the uterus, enhancing efficacy and reducing systemic side effects.

Intrauterine Drug Delivery Systems (IUDs): Overview

Classification of IUDs

Non-Hormonal IUDs

• Copper IUDs: Release copper ions with spermicidal effects.

• Examples: ParaGard, Multiload Cu375.

Hormonal IUDs

• Progestin IUDs: Release progestin to thicken cervical mucus, inhibit ovulation, and thin the uterine lining.

• Examples: Mirena, Kyleena, Skyla, Liletta.

Inert IUDs

• Made from non-reactive materials inducing a foreign body reaction to prevent fertilization.

• Examples: Lippes Loop, Stainless Steel Rings.

Bioactive IUDs

• Contain active substances like silver or gold to enhance efficacy and longevity.

Frame vs. Frameless IUDs

• Framed: T-shaped plastic frame holding copper or hormonal components.

• Examples: ParaGard, Mirena.

• Frameless: Attach directly to the uterine wall, reducing discomfort and expulsion risk.

• Example: GyneFix.

Mechanism of Action

Non-Hormonal IUDs (e.g., Copper IUDs):

• Induce a local inflammatory response.

• Copper ions act as spermicides, impairing sperm function and preventing fertilization.

Hormonal IUDs:

Release progestin to:

• Thicken cervical mucus, blocking sperm entry.

• Inhibit ovulation.

• Thin the uterine lining to reduce fertilization and implantation chances.

Advantages

1. Prolonged Action: Provides effects for months to years after placement.

2. Reduced Systemic Side Effects: Localized delivery minimizes systemic exposure.

3. Enhanced Compliance: Eliminates the need for daily or frequent dosing.

4. Reversible: Fertility usually returns to normal upon removal.

Disadvantages of Intrauterine Drug Delivery Systems

1. Insertion and Removal: Require medical procedures, which can be uncomfortable.

2. Localized Side Effects: Risk of pelvic inflammatory disease, uterine perforation, or increased bleeding/pain.

3. Migration and Expulsion: IUDs can move from their original position or be expelled.

4. No STI Protection: IUDs do not protect against sexually transmitted infections.