From the Guidelines
The two versions of oral doxycycline are doxycycline monohydrate and doxycycline hyclate, with the most commonly prescribed dose being 100 mg orally twice a day, as recommended by the Centers for Disease Control and Prevention 1. When considering the treatment options, it's essential to note that both formulations contain the same active antibiotic but differ in their salt forms and gastrointestinal side effect profiles.
- Doxycycline monohydrate tends to cause less gastrointestinal irritation, including less nausea, vomiting, and esophageal irritation, making it better tolerated by many patients.
- Doxycycline hyclate is more acidic and may cause more GI upset, but it is typically less expensive. Both versions are equally effective as antibiotics at equivalent doses, commonly prescribed at 100mg once or twice daily depending on the infection being treated. When taking either form, patients should swallow the medication with a full glass of water and remain upright for at least 30 minutes afterward to prevent esophageal irritation. Food can be taken with doxycycline to reduce stomach upset, though absorption may be slightly affected by dairy products, antacids, or supplements containing calcium, magnesium, iron, or aluminum, so these should be taken at least 2 hours before or after doxycycline. It's crucial to follow the prescribed dosage and administration guidelines to ensure the best possible outcome in terms of morbidity, mortality, and quality of life.
From the FDA Drug Label
Doxycycline hyclate is a yellow crystalline powder which is soluble in water. Each capsule, for oral administration, contains Doxycycline Hyclate, equivalent to 50 mg or 100 mg of Doxycycline. Each tablet, for oral administration, contains Doxycycline Hyclate, equivalent to 100 mg of Doxycycline The two versions of doxycycline PO are:
- Capsules: 50 mg and 100 mg
- Tablets: 100 mg 2
From the Research
Doxycycline PO Versions
The two versions of doxycycline PO are:
- 30-mg immediate-release and 10-mg delayed-release beads, which is a 40-mg formulation 3, 4, 5, 6
- No other version is mentioned in the provided studies, but it is known that doxycycline is available in other formulations, such as a 50-mg or 100-mg immediate-release formulation, however these are not mentioned in the provided studies.
Key Characteristics
Some key characteristics of the 40-mg formulation of doxycycline PO are:
- It is a subantimicrobial dose, meaning it is used for its anti-inflammatory properties rather than its antibacterial properties 5
- It is effective in treating papulopustular rosacea, with significant improvements in severity rating and erythema observed in clinical trials 3, 4, 6
- It is generally well-tolerated, with most adverse events being mild or moderate in severity 3, 4, 5, 6