emtricitabine/tenofovir vs valacyclovir
Side-by-side comparison of emtricitabine/tenofovir and valacyclovir. 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
Some examples include, but are not limited to, acyclovir, adefovir dipivoxil, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs [see Warnings and Precautions (5.3) ] .
Recommendation: Your doctor should monitor your kidney function closely while you are taking both of these medications.
Truvada, Descovy
Valtrex
Truvada is a medicine that contains two drugs, emtricitabine and tenofovir. It is used to treat HIV-1 infection and to prevent getting HIV-1.
Valacyclovir is an antiviral medicine. It is used to treat infections caused by certain viruses.
Truvada is used to treat HIV-1 infection in adults and children who weigh at least 37 pounds. It must be used with other HIV medicines. Truvada can also be used to help prevent getting HIV-1 in adults who are at high risk. When used for prevention, it is called PrEP (pre-exposure prophylaxis) and should be used with safer sex practices.
Valacyclovir treats cold sores, genital herpes, and shingles. For genital herpes, it can treat initial outbreaks, repeat outbreaks, and also prevent outbreaks. It can also lower the chance of spreading genital herpes to others.
Truvada contains two medicines that block HIV-1 reverse transcriptase. This enzyme is needed for HIV to multiply. By blocking this enzyme, Truvada helps to lower the amount of HIV in your body and prevent HIV infection.
Valacyclovir stops the virus from growing and spreading. It does this by blocking a key enzyme the virus needs to reproduce. This helps your body fight off the infection.
- • Diarrhea
- • Nausea
- • Tiredness
- • Headache
- • Dizziness
- • Headache
- • Nausea
- • Abdominal pain
- Drug Interaction 655
- Foetal Exposure During Pregnancy 621
- Anxiety 432
- Drug Resistance 431
- Virologic Failure 402
- Feeling very tired 2,294
- Loose, watery stools 2,120
- Feeling sick to your stomach 1,838
- Fever with low white blood cell count 1,545
- Fever 1,490
Truvada can cause serious side effects, including lactic acidosis and severe liver problems. Tell your doctor right away if you have any symptoms of these problems. If you have hepatitis B and stop taking Truvada, your hepatitis B may get worse. Your doctor will need to monitor you closely for several months if you stop taking Truvada. If you are using Truvada to prevent HIV, you must be tested to be sure you do not have HIV. If you take Truvada when you have HIV, the HIV virus can become resistant to the medicine.
Valacyclovir can cause serious problems like TTP/HUS, which is a blood disorder. This is more likely in people with advanced HIV or who have had bone marrow or kidney transplants, especially if they take high doses (8 grams per day). It can also cause kidney failure, especially in older adults or people with kidney problems. Rarely, it can cause confusion, hallucinations, or agitation. Stop taking this medicine and contact your doctor immediately if you experience any of these side effects.
Tell your doctor if you are pregnant or plan to become pregnant. Truvada should be used during pregnancy only if clearly needed. If you are infected with HIV, you should not breastfeed because you could pass HIV to your baby.
Tell your doctor if you are pregnant or plan to become pregnant. Studies haven't shown a risk of major birth defects, but there isn't enough data to be sure about miscarriage or other problems. Talk to your doctor about the risks and benefits.
How to Read This emtricitabine/tenofovir vs valacyclovir Comparison
emtricitabine/tenofovir is classified in the NRTI Combination (HIV PrEP) drug class, while valacyclovir sits within the Antiviral 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, emtricitabine/tenofovir has 2,541 submissions while valacyclovir has 9,287. 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 both of these drugs are removed from the body through the kidneys, and taking them together can increase the risk of kidney damage.. 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 emtricitabine/tenofovir and valacyclovir - 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.