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metronidazole vs theophylline

Side-by-side comparison of metronidazole and theophylline. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

major Known Drug Interaction

albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...

Recommendation: Your doctor should monitor your theophylline levels while you are on this medication. Tell your doctor if you experience a persistent headache or feel very dizzy.

Drug Class
metronidazole Nitroimidazole Antibiotic
theophylline Methylxanthine Bronchodilator
Type
metronidazole Prescription
theophylline Prescription
Summary
metronidazole

Metronidazole is an antibiotic medicine. It fights bacteria and certain parasites in your body.

theophylline

Theophylline is a medicine that helps you breathe easier. It treats the symptoms of asthma and other lung problems.

What It Treats
metronidazole

Metronidazole treats infections like trichomoniasis, amebiasis, and certain anaerobic bacterial infections. Trichomoniasis is a sexually transmitted infection. Amebiasis includes infections of the intestines and liver. Anaerobic bacteria cause infections inside the abdomen, on the skin, and in the female reproductive system.

theophylline

Theophylline treats the symptoms of long-term asthma and other lung diseases. These include emphysema and chronic bronchitis, which make it hard to breathe. This medicine helps to open up your airways so you can breathe easier.

How It Works
metronidazole

Metronidazole works by entering the bacteria or parasite and damaging its DNA. This damage stops the bacteria or parasite from growing and multiplying. Eventually, the infection is cleared.

theophylline

Theophylline is a bronchodilator. It works by relaxing the muscles in your airways. This allows more air to flow in and out of your lungs.

Common Side Effects
metronidazole
  • Nausea
  • Headache
  • Loss of appetite
  • Vomiting
  • Diarrhea
theophylline
  • Nausea
  • Vomiting
  • Headache
  • Trouble sleeping (insomnia)
FAERS Reports
metronidazole
  • Nausea 4,691
  • Diarrhoea 4,116
  • Vomiting 3,283
  • Pyrexia 3,224
  • Drug Hypersensitivity 3,138
theophylline
  • Difficulty breathing 2,273
  • Asthma 1,942
  • Pneumonia 1,317
  • Wheezing 1,306
  • Vomiting 1,101
Serious Warnings
metronidazole

Metronidazole can cause cancer in mice and rats. Only use it for the conditions listed in this leaflet. Do not drink alcohol or use products with propylene glycol while taking this medicine, and for 3 days after.

theophylline

If your theophylline levels get too high in your blood, it can cause serious side effects. These include severe vomiting, irregular heartbeats, and seizures. These can be life-threatening.

Pregnancy
metronidazole

Do not take metronidazole during the first three months of pregnancy. Talk to your doctor if you are pregnant or breastfeeding before taking this medicine.

theophylline

It is not known if theophylline can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if theophylline passes into breast milk, so talk to your doctor if you are breastfeeding.

How to Read This metronidazole vs theophylline Comparison

metronidazole is classified in the Nitroimidazole Antibiotic drug class, while theophylline sits within the Methylxanthine Bronchodilator 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, metronidazole has 18,452 submissions while theophylline has 7,939. 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 major interaction flagged in FDA labeling, attributed to metronidazole may reduce the speed at which your liver clears theophylline from your blood. this can cause the drug to reach levels that are toxic to your body.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between metronidazole and theophylline - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.