What is the dosage and usage of Lo Loestrin (ethinyl estradiol and norgestrel) for a female patient of reproductive age with no contraindications?

Lo Loestrin Fe Dosing and Administration

Lo Loestrin Fe should be prescribed as one tablet taken orally at the same time every day for 28 consecutive days, then immediately starting a new pack without interruption. 1

Standard Prescription Format

• Dispense: 28 tablets per pack 1
• Instructions: Take 1 tablet by mouth daily at the same time each day for 28 days, then start a new pack immediately without a pill-free interval 1
• Approved age: Women ≥15 years of age for contraception 1
• Pre-menarchal patients: Safety and efficacy not established 1

Initiation Timing

• Begin therapy either on the first day of the menstrual period or the first Sunday after the onset of menstruation 2
• "Quick start" method: Can be initiated on the same day as the visit in healthy, nonpregnant patients 2
• Backup contraception: Use condoms or abstinence for at least the first 7 days for contraceptive efficacy 2
• STI protection: Condoms should be used at all times for protection against sexually transmitted infections 2

Pre-Prescription Requirements

Before prescribing, you must:

• Confirm negative pregnancy status with urine pregnancy test 2, 1
• Measure baseline blood pressure 2, 1
• Perform breast and pelvic examinations, including Papanicolaou smear 2
• Screen for absolute contraindications 1

Absolute Contraindications to Avoid

Do not prescribe Lo Loestrin Fe if the patient has: 2, 1

• Active or history of thromboembolic disease (deep vein thrombosis, pulmonary embolism)
• Current or history of breast cancer or other estrogen/progestin-sensitive cancers
• Undiagnosed abnormal uterine bleeding
• Active hepatic disease, hepatic tumors, or severe decompensated cirrhosis
• Pregnancy
• Age ≥35 years with smoking history (any amount)
• Uncontrolled hypertension (systolic ≥160 mm Hg or diastolic ≥100 mm Hg)
• Migraine headaches with focal neurologic symptoms (aura) at any age
• Cerebrovascular disease or coronary artery disease
• Diabetes with vascular complications
• Major surgery with prolonged immobilization

Ongoing Monitoring

• Blood pressure: Check at all follow-up visits 2, 1
• Health status assessment: Evaluate for cardiovascular or thromboembolic symptoms at each visit 1
• Routine follow-up: Schedule a visit 1 to 3 months after initiation to address adverse effects or adherence issues 2
• Prescription duration: The CDC recommends prescribing up to 1 year of combined oral contraceptives at a time 2

Critical Drug Interactions Requiring Alternative Contraception

Document and counsel patients about major interactions that reduce contraceptive efficacy: 2, 1

• Anticonvulsants (phenytoin, carbamazepine, barbiturates)
• Antibiotics (rifampin; note that most common antibiotics like penicillins, tetracyclines, and macrolides have minimal interaction)
• HIV protease inhibitors
• St. John's wort
• Hepatitis C antivirals
• Griseofulvin
• Modafinil

Common Adverse Effects to Counsel About

Inform patients that transient adverse effects may include: 2

• Irregular bleeding (most common initially)
• Headache
• Nausea
• Breast tenderness
• Weight changes

These effects typically improve over time with continued use. 2

Critical Safety Information

• Venous thromboembolism risk: Increases from 1 per 10,000 to 3-4 per 10,000 woman-years during combined oral contraceptive use 2
• Smoking in patients <35 years: While smoking should be discouraged, it is not an absolute contraindication to combined oral contraceptive use in teenagers and adults younger than 35 years old 2
• No gynecologic examination required: Although inspection of external genitalia and STI screening are recommended for sexually active patients, no pelvic examination is needed to determine eligibility for combined oral contraceptive use 2

Common Prescribing Pitfalls to Avoid

• Never prescribe without confirming negative pregnancy status 1
• Never skip baseline blood pressure measurement 1
• Do not overlook cardiovascular risk factors, particularly in patients ≥35 years who smoke 1
• Do not forget to counsel about backup contraception for the first 7 days 2
• Do not assume all antibiotics reduce efficacy—only specific medications like rifampin significantly interact 2