Drug Guide

Generic Name

Levonorgestrel

Brand Names Norplant, Norplant System In Plastic Container, Jadelle, Plan B, Mirena, Plan B One-step, Fallback Solo, Opcicon One-step, Skyla, Liletta, Athentia Next, Her Style, Kyleena

Classification

Therapeutic: Hormonal Contraceptive/Progestin-only contraceptive

Pharmacological: Progestin

FDA Approved Indications

Prevention of pregnancy
Emergency contraception (Plan B, Plan B One-step, Opcicon One-step)

Mechanism of Action

Levonorgestrel primarily works by inhibiting ovulation, thickening cervical mucus to prevent sperm penetration, and altering endometrial lining to prevent implantation.

Dosage and Administration

Adult: Varies by product; e.g., for emergency contraception, typically a single dose of 1.5 mg taken as soon as possible within 72 hours of unprotected intercourse.

Pediatric: Not indicated for pediatric use.

Geriatric: Not indicated for use in elderly women.

Renal Impairment: No specific adjustments; caution advised.

Hepatic Impairment: Use with caution; no specific dosing recommendations.

Pharmacokinetics

Absorption: Rapid absorption after oral administration in emergency contraception.

Distribution: Widely distributed; high plasma protein binding (~98%).

Metabolism: Primarily hepatic via reduction and conjugation.

Excretion: Metabolites excreted mainly in urine; small amount in feces.

Half Life: Approximately 20 hours.

Contraindications

Known or suspected pregnancy
History of thromboembolic disorders
Hepatic impairment or disease
Porphyria

Precautions

Use with caution in women with risk factors for cardiovascular disease; monitor for adverse effects.

Adverse Reactions - Common

Irregular vaginal bleeding or spotting (Common)
Headache (Common)
Nausea (Common)
Breast tenderness (Common)

Adverse Reactions - Serious

Thromboembolic events (Rare)
Liver dysfunction or tumors (Rare)
Allergic reactions including rash, itching, swelling (Rare)

Drug-Drug Interactions

Other hormonal medications, anticoagulants, enzyme inducers like rifampin and carbamazepine

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Assess pregnancy status, menstrual history, and risk factors for adverse effects.

Diagnoses:

Risk of ineffective protection from pregnancy
Risk for thromboembolic phenomena

Implementation: Administer as per product specifications, counsel about effectiveness, side effects, and proper use.

Evaluation: Monitor for pregnancy, evaluate for adverse reactions and compliance.

Patient/Family Teaching

Use consistently and as directed for contraceptive effectiveness.
Inform about possible side effects such as irregular bleeding.
Explain emergency contraception instructions if applicable.
Advise on signs of thromboembolic events and when to seek medical care.

Special Considerations

Black Box Warnings:

Not to be used as routine contraception without medical consultation.
Emergency contraception should be used within 72 hours for maximum effectiveness.

Genetic Factors: No specific genetic considerations.

Lab Test Interference: Hormonal contraceptives may affect ovarian and endometrial biopsy results.

Overdose Management

Signs/Symptoms: Nausea, vomiting, dizziness, or vaginal bleeding.

Treatment: Supportive care; no specific antidote.

Storage and Handling

Storage: Store at room temperature, away from light and moisture.

Stability: Stable under recommended storage conditions.