Tri-Mili: A Triphasic Oral Contraceptive
Tri-Mili (28) 0.18 mg (7)/0.215 mg(7)/0.25 mg(7) - 0.035mg is a triphasic combined oral contraceptive (COC) containing varying doses of norgestimate and a consistent dose of ethinyl estradiol used for pregnancy prevention.
Composition and Mechanism
Tri-Mili is a triphasic oral contraceptive that contains:
- Norgestimate in three different doses (0.18 mg, 0.215 mg, and 0.25 mg) for 7 days each
- Ethinyl estradiol 0.035 mg consistently throughout the 21 active pills
- 7 inert/placebo pills to complete the 28-day pack
This medication works primarily by:
- Inhibiting ovulation
- Thickening cervical mucus to prevent sperm penetration
- Altering the endometrial lining to reduce likelihood of implantation
Effectiveness
Tri-Mili, like other combined oral contraceptives, has:
- Typical use effectiveness rate of 91-95% 1
- Perfect use effectiveness approaching 99%
- Failure rates similar to other low-dose combined hormonal contraceptives
Administration
- Take one pill daily at approximately the same time
- Pills are taken in sequence following the package directions
- The first 21 pills contain active hormones
- The last 7 pills are hormone-free and during this time withdrawal bleeding typically occurs
- Can be used in extended-cycle regimens (84 active pills followed by 7 hormone-free days) for conditions like dysmenorrhea or endometriosis 1
Benefits Beyond Contraception
Tri-Mili, like other COCs, provides several non-contraceptive benefits:
- Decreased menstrual bleeding and cramping
- Reduced frequency of menstrual periods when used in extended regimens
- Improvement in conditions exacerbated by menstruation (anemia, dysmenorrhea, endometriosis)
- Management of acne due to its anti-androgenic properties
- Reduced risk of ovarian and endometrial cancers
Contraindications
Tri-Mili should not be used in women with:
- History of venous thromboembolism or arterial thrombotic disease
- Breast or endometrial carcinoma
- Undiagnosed abnormal genital bleeding
- Severe hypertension
- Diabetes with vascular involvement
- Headaches with focal neurological symptoms or migraine with aura
- Liver tumors
- Age ≥35 years who smoke 1
- Hypersensitivity to any component of the medication
Common Side Effects
- Headache
- Nausea and vomiting
- Breakthrough bleeding or spotting
- Breast tenderness
- Mood changes
- Weight changes 1
Important Considerations
Drug Interactions
Certain medications may reduce the effectiveness of Tri-Mili:
- Antibiotics
- Anticonvulsants
- Antifungals
- HIV protease inhibitors
- Rifampin
- St. John's wort 1
Women taking these medications should use backup contraception.
Risk of Thromboembolism
- COCs increase the risk of venous thromboembolism three to fourfold from the baseline incidence of up to 1 per 10,000 woman-years in adolescents 1
- The risk is lower with newer progestins but still present with all estrogen-containing contraceptives
Special Populations
For women with certain medical conditions, alternative contraceptive methods may be preferable:
- Women with stable systemic lupus erythematosus (SLE) and no antiphospholipid antibodies may benefit from IUDs or subdermal progestin implants 1
- Women with HIV may need to consider potential drug interactions between antiretrovirals and hormonal contraceptives 2
Alternative Contraceptive Options
For women who cannot or prefer not to use combined hormonal contraceptives:
- IUDs (>99% effective)
- Subdermal progestin implants (>99% effective)
- Injectable medroxyprogesterone acetate (94-99% effective)
- Progestin-only pills (87-99% effective)
- Barrier methods like condoms (79-95% effective) 1
Tri-Mili represents a standard triphasic combined oral contraceptive option with effectiveness comparable to other combined hormonal methods when used correctly and consistently.