terbinafine vs trimethoprim
Side-by-side comparison of terbinafine and trimethoprim. 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
The influence of terbinafine on the pharmacokinetics of fluconazole, cotrimoxazole (trimethoprim and sulfamethoxazole), zidovudine or theophylline was not considered to be clinically significant.
Recommendation: You can typically take these medications together without needing any dose changes.
Lamisil
Primsol
Terbinafine is an antifungal medicine. It is used to treat fungal infections of the fingernails and toenails.
This medicine contains sulfamethoxazole and trimethoprim. It is an antibiotic that fights bacteria in your body.
Terbinafine treats onychomycosis, a fungal infection of the toenails or fingernails. Before you start taking this medicine, your doctor should take a nail sample. This is to make sure the infection is caused by a fungus.
This medicine can treat urinary tract infections, ear infections in children, and bronchitis in adults. It also treats shigellosis, a type of diarrhea. It can also treat or prevent Pneumocystis jiroveci pneumonia, and treat traveler's diarrhea.
Terbinafine belongs to a class of medicines called allylamine antifungals. It works by stopping the growth of fungi. This eventually kills the fungus causing the infection.
This medicine works by stopping bacteria from making folic acid. Bacteria need folic acid to grow and multiply. By blocking folic acid production, the medicine kills the bacteria.
- • Headache
- • Diarrhea
- • Rash
- • Upset stomach
- • Abnormal liver enzyme tests
- • Nausea
- • Vomiting
- • Loss of appetite
- • Skin rash
- • Hives
- Skin rash 391
- Itching 316
- Tiredness 300
- Feeling sick to your stomach 280
- Loss of taste 270
- Nausea 945
- Diarrhoea 848
- Headache 835
- Malaise 815
- Pyrexia 721
Terbinafine can cause liver problems, including liver failure. Your doctor should check your liver before you start taking it and regularly while you are taking it. Tell your doctor right away if you have nausea, loss of appetite, tiredness, vomiting, pain in your upper right belly area, yellowing of the skin or eyes, dark urine, or pale stools. If you have taste changes, stop taking terbinafine. These changes can be severe, long-lasting, or even permanent. Tell your doctor if you feel depressed or have other mood changes.
Rarely, sulfonamide drugs like this one have caused severe reactions. These include Stevens-Johnson syndrome, toxic epidermal necrolysis, liver damage, and blood problems. Tell your doctor right away if you have a fever, rash, blisters, mouth sores, or signs of infection.
Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if terbinafine will harm your unborn baby. Terbinafine passes into breast milk. Talk to your doctor about the risks and benefits of breastfeeding while taking this medicine.
Tell your doctor if you are pregnant or plan to become pregnant. This medicine may not be safe for your baby. Talk to your doctor about the risks and benefits of taking this medicine while breastfeeding.
How to Read This terbinafine vs trimethoprim Comparison
terbinafine is classified in the Allylamine Antifungal drug class, while trimethoprim sits within the Dihydrofolate Reductase Inhibitor 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, terbinafine has 1,557 submissions while trimethoprim has 4,164. 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 terbinafine does not significantly change how the body handles trimethoprim.. 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 terbinafine and trimethoprim - 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.