What are the side effects of Slynd (progestin-only pill)?

Side Effects of Slynd (Progestin-Only Pill)

The most common side effects of Slynd (drospirenone) include irregular bleeding patterns, which may manifest as breakthrough bleeding, spotting, or changes in menstrual cycle length, affecting up to 25% of progestin-only pill users. 1, 2

Common Side Effects

• Menstrual irregularities:

  • Breakthrough bleeding
  • Spotting
  • Prolonged bleeding
  • Changes in frequency of bleeding
  • Lengthened cycles

• Other common side effects:

  • Headache
  • Nausea
  • Breast tenderness
  • Mood changes

Cardiovascular Safety Profile

Slynd, as a progestin-only pill, has a more favorable cardiovascular safety profile compared to combined hormonal contraceptives:

• No increased risk of venous thromboembolism (VTE) - Unlike combined hormonal contraceptives which increase VTE risk from 1 per 10,000 to 3-4 per 10,000 woman-years 3
• No significant effect on blood pressure - Unlike combined pills which can increase hypertension risk (relative risk 1.8) 3
• Lower thrombotic risk - Studies show progestin-only pills have a relative risk of 0.90 (95% CI 0.57–1.45) for VTE compared to non-users 1

Special Considerations

Advantages for High-Risk Patients

Slynd is particularly suitable for women with:

• History of or risk factors for venous thromboembolism
• Hypertension
• Migraine with aura
• Age over 35 years who smoke
• Antiphospholipid antibodies

For these patients, progestin-only pills are strongly recommended over combined hormonal contraceptives 1, 3.

Unique Properties of Drospirenone

Drospirenone has anti-mineralocorticoid properties that may:

• Help decrease blood pressure in some users 3
• Rarely cause hyperkalemia in women with risk factors 3

Management of Side Effects

Most adverse effects of hormonal contraceptives diminish with continued use:

• Irregular bleeding:

  • Usually improves within 3-5 months of continued use 4
  • If significant abnormal bleeding persists beyond 3 months, evaluation for other causes may be needed 4

• Other side effects:

  • Reassurance that symptoms typically resolve within 3-5 months is often sufficient 4
  • Unlike with combined pills, switching between different progestin-only formulations has not been well-studied for managing side effects

Important Warnings

• Hyperkalemia risk: Monitor potassium levels in patients with renal insufficiency or those taking medications that can increase potassium levels
• Bone mineral density: Unlike depot medroxyprogesterone acetate (DMPA), Slynd is not associated with significant bone mineral density loss 1
• Acne: If acne develops or worsens with progestin-only contraceptives, switching to a combination method should be considered if medically eligible 4

Monitoring Recommendations

• Follow-up visit 1-3 months after initiation to address adverse effects or adherence issues 3
• Regular blood pressure monitoring throughout therapy 3
• Be alert for warning signs of serious complications, though these are rare with progestin-only methods 3

Bleeding irregularities remain the most common reason for discontinuation of progestin-only pills, accounting for up to 25% of discontinuations 2. Patient education about expected side effects before starting Slynd can improve adherence and continuation rates.