doxycycline vs phenobarbital
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Side-by-side comparison of doxycycline and phenobarbital. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
Doxycycline Phenobarbital has been shown to shorten the half-life of doxycycline for as long as 2 weeks after barbiturate therapy is discontinued. If phenobarbital and doxycycline are administered concurrently, the clinical response to doxycycline should be monitored closely.
Vibramycin, Doryx
Luminal
Doxycycline is an antibiotic medicine. It fights bacteria in your body to treat different kinds of infections.
Phenobarbital is a medicine that can help control seizures and calm you down. It belongs to a class of drugs called barbiturates.
Doxycycline treats many types of infections caused by bacteria. This includes infections like Rocky Mountain spotted fever, typhus, Q fever, and certain respiratory infections. It also treats sexually transmitted infections like gonorrhea and chlamydia, as well as other infections like plague and tularemia.
This medicine is used to treat generalized and partial seizures. Seizures are caused by unusual electrical activity in the brain. Phenobarbital helps to reduce this activity and prevent seizures.
Doxycycline belongs to a class of drugs called tetracycline antibiotics. It works by stopping the growth of bacteria. This helps your body fight off the infection.
Phenobarbital works by slowing down the activity of your brain and nervous system. It increases the effects of a natural chemical in the body called GABA. This helps to reduce seizures and promote relaxation.
- • Nausea
- • Vomiting
- • Diarrhea
- • Rash
- • Photosensitivity (increased sensitivity to sunlight)
- • Drowsiness
- • Sedation
- • Lethargy
- • Vertigo
- Nausea 4,769
- Fatigue 4,419
- Rash 3,945
- Diarrhoea 3,843
- Pain 3,835
- Seizure 1,534
- Drug Interaction 635
- Toxicity To Various Agents 621
- Status Epilepticus 482
- Multiple-Drug Resistance 442
Doxycycline can cause permanent tooth discoloration if used during tooth development (pregnancy, infancy, childhood up to 8 years old). It can also cause increased pressure inside the skull. Tell your doctor right away if you have blurred vision, double vision, or a severe headache.
You should not take this medicine if you are allergic to barbiturates. Also, do not take it if you have a history of porphyria, severe liver problems, or breathing problems.
Doxycycline can harm an unborn baby. Do not use this medicine if you are pregnant. Doxycycline can pass into breast milk and may affect bone and tooth development in the nursing infant. Talk to your doctor about the best way to feed your baby if you are taking this medicine.
Tell your doctor if you are pregnant or plan to become pregnant. Phenobarbital can harm an unborn baby. Talk to your doctor about the risks and benefits of taking this medicine while breastfeeding.
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How to Read This doxycycline vs phenobarbital Comparison
doxycycline is classified in the Tetracycline Antibiotic drug class, while phenobarbital sits within the Anticonvulsant (Barbiturate) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, doxycycline has 20,811 submissions while phenobarbital has 3,714. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to phenobarbital causes your body to get rid of the antibiotic doxycycline more quickly, which could make it less effective at fighting infections.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for doxycycline or phenobarbital.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.