Tetracycline antibiotic

Vibramycin (doxycycline)

Also marketed as Doryx. An approved treatment for Bartonellosis.

FDA Approved (1967)
Preclinical
Phase 1
Phase 2
Phase 3
Approved
1967
Drug facts

The same compound appears under different names depending on the context. Here is how to identify Doxycycline wherever you encounter it, plus the key facts at a glance.

Generic name
Doxycycline
Brand names
Vibramycin, Doryx
Drug class
Tetracycline antibiotic
How it's taken
For Bartonella endocarditis, doxycycline 100 mg twice daily is given for 6 weeks, with gentamicin added for the first 2 weeks.

A tetracycline antibiotic used with gentamicin for Bartonella endocarditis (rifampin can replace gentamicin if kidney problems rule it out) and as part of extended regimens for chronic bartonellosis. Often combined with other antibiotics in LLMD treatment protocols.

How Doxycycline works

Doxycycline blocks protein synthesis in Bartonella bacteria by binding the 30S ribosomal subunit. It concentrates inside endothelial cells where Bartonella resides. For bartonellosis, it is rarely used alone because Bartonella can persist intracellularly; combination therapy with rifampin or a macrolide is preferred for deeper tissue penetration.

Mechanism: Tetracycline antibiotic that inhibits protein synthesis by binding the 30S ribosomal subunit

Side effects and safety

What patients report

Common side effects include nausea, esophageal irritation (take with water, stay upright), photosensitivity, and gastrointestinal upset. Can cause permanent tooth staining in children under 8. Yeast infections are common during extended courses. Serious risks include severe diarrhea from C. difficile infection (which can start even 2 or more months after the last dose and can be fatal), severe skin reactions such as Stevens-Johnson syndrome or DRESS (stop the drug and get care right away), and raised pressure inside the skull (headache, blurred or double vision), which can cause lasting vision loss. The label also warns that doxycycline may harm an unborn baby and advises periodic blood, kidney, and liver tests during long-term use.

This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.

Taking Doxycycline

For Bartonella endocarditis, doxycycline 100 mg twice daily is given for 6 weeks, with gentamicin added for the first 2 weeks. For chronic bartonellosis, LLMD protocols may prescribe 100 mg twice daily combined with rifampin for 3 to 6 months. Doxycycline is widely available as a generic and under brands such as Doryx MPC; Pfizer's original Vibramycin oral products are listed as discontinued on their current FDA label.

Availability and cost

Generic available

Generic versions may be available at a lower cost. Ask your pharmacist.

Help paying for Vibramycin

Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.

Your insurance
From the drugmaker
Vibramycin (Doxycycline)

No drugmaker assistance program for this medicine is published on the maker's official pages.

Good to know: Doxycycline is an older antibiotic sold as a low-cost generic by many manufacturers. There is no single manufacturer assistance program for it. Pharmacy discount programs or a pharmacist can help with cost.

Checked on the drugmaker's official pages on September 24, 2026. Programs change; confirm with the program before you rely on it.

More ways to get help paying for treatment →

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Common questions about Doxycycline

▸What is Doxycycline (Vibramycin)?

A tetracycline antibiotic used with gentamicin for Bartonella endocarditis (rifampin can replace gentamicin if kidney problems rule it out) and as part of extended regimens for chronic bartonellosis. Often combined with other antibiotics in LLMD treatment protocols.

▸How does Doxycycline work?

Doxycycline blocks protein synthesis in Bartonella bacteria by binding the 30S ribosomal subunit. It concentrates inside endothelial cells where Bartonella resides. For bartonellosis, it is rarely used alone because Bartonella can persist intracellularly; combination therapy with rifampin or a macrolide is preferred for deeper tissue penetration.

▸What are the side effects of Doxycycline?

Common side effects include nausea, esophageal irritation (take with water, stay upright), photosensitivity, and gastrointestinal upset. Can cause permanent tooth staining in children under 8. Yeast infections are common during extended courses. Serious risks include severe diarrhea from C. difficile infection (which can start even 2 or more months after the last dose and can be fatal), severe skin reactions such as Stevens-Johnson syndrome or DRESS (stop the drug and get care right away), and raised pressure inside the skull (headache, blurred or double vision), which can cause lasting vision loss. The label also warns that doxycycline may harm an unborn baby and advises periodic blood, kidney, and liver tests during long-term use.

▸How is Doxycycline taken?

For Bartonella endocarditis, doxycycline 100 mg twice daily is given for 6 weeks, with gentamicin added for the first 2 weeks. For chronic bartonellosis, LLMD protocols may prescribe 100 mg twice daily combined with rifampin for 3 to 6 months. Doxycycline is widely available as a generic and under brands such as Doryx MPC; Pfizer's original Vibramycin oral products are listed as discontinued on their current FDA label.

▸Is Doxycycline FDA approved?

Yes, Doxycycline (Vibramycin) is FDA approved (1967) for the treatment of Bartonellosis.

This page is for informational purposes only and does not constitute medical advice. Drug information is sourced from public databases and peer-reviewed literature and may not reflect the most recent updates. Always discuss treatment options with your healthcare provider. Last reviewed: September 2026.

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