What are the available Oral Contraceptive Pills (OCPs) in Canada?

Available Oral Contraceptive Pills in Canada

In Canada, the vast majority of currently available combined hormonal contraceptives contain ≤50 μg of ethinyl estradiol combined with a second, third, or fourth generation progestin 1.

Combined Oral Contraceptives (COCs)

Estrogen Components

• Ethinyl estradiol (EE): Most common estrogen component in COCs
  • Daily doses typically range from 10-50 μg 2
  • Low-dose formulations (20-35 μg) are recommended as first-line options 3
• Newer natural estrogens:
  • Estradiol valerate (prodrug of estradiol)
  • Estetrol (fetal estrogen) 1
  • These may have fewer adverse effects on blood pressure than ethinyl estradiol 3

Progestin Components (by generation)

1. First generation:

   • Norethindrone
   • Ethynodiol diacetate 2

2. Second generation:

   • Levonorgestrel
   • Norgestrel 2

3. Third generation (less androgenic than prior generations):

   • Norgestimate
   • Desogestrel 2

4. Fourth generation:

   • Drospirenone (spironolactone analogue with anti-androgenic properties)
   • Dienogest 2, 1

Dosing Regimens Available

• Monophasic: Same dose of hormones in each pill
• Multiphasic: Varying weekly hormone doses to mimic the menstrual cycle
• Cyclic formulations: Active hormone pills for 21-24 days followed by placebo pills for 7-4 days
• Extended cyclic formulations: Active hormone pills for 84 days followed by placebo pills for 7 days
• Continuous formulations: No hormone-free interval 1

Progestin-Only Pills (POPs)

• Available formulations contain:
  • Norethindrone (first generation)
  • Drospirenone (fourth generation) 1
• Work primarily by thickening cervical mucus rather than inhibiting ovulation 4
• Require more stringent adherence than combined methods 4
• Provide an option for patients with contraindications to estrogen use 4

Prevalence and Usage Patterns in Canada

• Approximately 1.3 million (16%) Canadian women aged 15-49 reported taking OCPs 5
• OCP use decreases with age:
  • 30% among 15-19 year-olds
  • 3% among 40-49 year-olds 5
• Almost all (99%) OCP users in Canada take combined formulations containing ethinyl estradiol and progestin 5
• Two-thirds of Canadian OCP users take formulations containing 30 μg or more of ethinyl estradiol 5
• Younger women (15-24) are more likely to use lower-dose formulations (<30 μg EE) 5

Efficacy and Safety Considerations

• Typical failure rates for OCPs are 7.2-9% with typical use 6, 7
• Low-dose OCPs (≤35 μg EE) increase VTE risk from baseline 1 per 10,000 to 3-4 per 10,000 woman-years, which is substantially lower than pregnancy-associated VTE risk 3
• Drospirenone-containing OCPs may have beneficial effects on blood pressure 3
• Formulations with 20 μg EE and drospirenone are particularly indicated for women with pre-existing mastodynia or fibrocystic breast manifestations 8

Emergency Contraceptive Pills Available

• Levonorgestrel (Plan B):
  • Single 1.5 mg dose or two 0.75 mg doses 12 hours apart 9
• Ulipristal acetate:
  • May be more effective than levonorgestrel at the end of the 5-day window
  • May be more effective in women who weigh more than 165 pounds 4
• Combined estrogen and progestin (Yuzpe regimen):
  • Less effective than other options and has more side effects 9

Clinical Pearls

• The American Academy of Pediatrics recommends levonorgestrel/ethinyl estradiol 30-35 μg and norgestimate/ethinyl estradiol 30-35 μg as starting options due to their well-established safety profiles 3
• Efficacy can be compromised by missed pills, particularly when two or more consecutive pills are missed 3
• For women with acne, COCs containing drospirenone have been found to be as effective as formulations with cyproterone acetate 8
• OCPs provide numerous non-contraceptive benefits, including protection against ovarian and endometrial cancers, reduced dysmenorrhea, and improvement in acne 10