famciclovir vs theophylline
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Side-by-side comparison of famciclovir and theophylline. 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
7.2 Potential for Other Drugs to Affect Penciclovir No clinically significant alterations in penciclovir pharmacokinetics were observed following single-dose administration of 500 mg famciclovir after pretreatment with multiple doses of allopurinol, cimetidine, theophylline, zidovudine, promethazine, when given shortly after an antacid (magnesium and aluminum hydroxide), or concomitantly with emtricitabine.
Famvir
Theo-24, Elixophyllin
Famciclovir is an antiviral medicine. It helps to treat infections caused by certain viruses.
Theophylline is a medicine that helps you breathe easier. It treats the symptoms of asthma and other lung problems.
This medicine treats herpes infections. It can treat cold sores, genital herpes, and shingles. It can also prevent genital herpes outbreaks. This medicine may not work for everyone, including first-time genital herpes, eye shingles, or certain immunocompromised patients.
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.
Famciclovir stops the virus from multiplying. It does this by blocking a key enzyme the virus needs to make copies of itself. This helps your body fight off the infection.
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.
- • Headache
- • Nausea
- • Nausea
- • Vomiting
- • Headache
- • Trouble sleeping (insomnia)
- Fatigue 185
- Diarrhoea 179
- Nausea 145
- Headache 135
- Pain 118
- Dyspnoea 2,273
- Asthma 1,942
- Pneumonia 1,318
- Wheezing 1,306
- Vomiting 1,101
If you have kidney problems, make sure your doctor knows. Taking too much famciclovir when you have kidney problems can damage your kidneys.
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.
Tell your doctor if you are pregnant or plan to become pregnant. Untreated herpes during pregnancy can harm the baby. It is not known if famciclovir passes into breast milk.
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.
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How to Read This famciclovir vs theophylline Comparison
famciclovir is classified in the Antiviral (Nucleoside Analog) 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, famciclovir has 762 submissions while theophylline has 7,940. 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 studies show that theophylline does not change how the body breaks down or uses famciclovir.. 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 famciclovir or theophylline.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.