Class Name(s):

• 8:18.08.20 HIV Nucleoside and Nucleotide Reverse Transcriptase Inhibitors

Pronunciation:

• (la miv' ue deen)(te noe' fo veer)

Brand Name(s):

• Cimduo^®

Other Name(s):

• 3TC and TDF

IMPORTANT WARNING:

Lamivudine and tenofovir should not be used to treat hepatitis B virus infection (HBV; an ongoing liver infection). Tell your doctor if you have or think you may have HBV. Your doctor may test you to see if you have HBV before you begin your treatment with lamivudine and tenofovir. If you have HBV and you take lamivudine and tenofovir, your condition may suddenly worsen when you stop taking it. Your doctor will examine you and order lab tests regularly for several months after you stop taking lamivudine and tenofovir.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests to check your body's response to lamivudine and tenofovir.

WHY is this medicine prescribed?

The combination of lamivudine and tenofovir is used to treat HIV. Lamivudine and tenofovir are in a class of medications called nucleoside and nucleotide reverse transcriptase inhibitors (NRTIs). They work by slowing the spread of HIV in the body.

Although, lamivudine and tenofovir will not cure HIV. it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses. Taking this medication and making other lifestyle changes may also decrease the risk of giving the HIV virus to other people.

HOW should this medicine be used?

The combination of lamivudine and tenofovir comes as a tablet to take by mouth. Take with or without food once a day. Take lamivudine and tenofovir at around the same time every day.

Take lamivudine and tenofovir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Continue to take lamivudine and tenofovir even if you feel well. Do not stop taking lamivudine and tenofovir without talking to your doctor. If you stop taking lamivudine and tenofovir even for a short time, or if you skip doses, the virus may become resistant to medications and may be harder to treat.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Are there OTHER USES for this medication?

The combination of lamivudine and tenofovir is also sometimes used to treat healthcare workers or other individuals exposed to HIV infection after accidental contact with HIV-contaminated blood, tissues, or other body fluids. Talk to your doctor about the risks of using this medication for your condition.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before taking lamivudine and tenofovir,

• tell your doctor or pharmacist if you are allergic to this drug, any part of this drug, or any other drugs, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking lamivudine and tenofovir. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• the following nonprescription or herbal products may interact with lamivudine and tenofovir: nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve). Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking lamivudine and tenofovir. Do not start any of these medications while taking lamivudine and tenofovir without discussing with your healthcare provider.
• tell your doctor if you have any of the conditions mentioned in the IMPORTANT WARNING section, or if you have or have ever had bone problems including osteoporosis (a condition in which the bones become thin and weak and break easily) or bone fractures, hepatitis C or other liver disease, or kidney disease. For children taking this medication, tell your doctor if they have or have ever had pancreatitis.
• tell your doctor if you are pregnant, or plan to become pregnant. If you become pregnant while taking lamivudine and tenofovir call your doctor.
• tell your doctor if you are breastfeeding or plan to breastfeed. Some of the medication and HIV may be passed to your baby in your breast milk. Talk to your doctor about the risks of breastfeeding your baby if you are taking lamivudine and tenofovir.
• you should be aware that your body fat may increase or move to different areas of your body, such as your upper back, neck (''buffalo hump''), breasts, and around your stomach. You may notice a loss of body fat from your face, legs, and arms.
• you should know that while you are taking medications to treat HIV infection, your immune system may get stronger and begin to fight other infections that were already in your body or cause other conditions to occur. This may cause you to develop symptoms of those infections or conditions. If you have new or worsening symptoms during your treatment with lamivudine and tenofovir be sure to tell your doctor.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Lamivudine and tenofovir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• stomach pain
• nausea
• vomiting
• diarrhea
• heartburn
• lack of energy
• back pain
• muscle or joint pain
• depressed feeling
• anxiety
• trouble falling asleep or staying asleep
• dizziness
• stinging, burning, or painful feeling in arms or legs
• itching or rash

Some side effects can be serious. If you experience any of these symptoms call your doctor immediately or get emergency medical treatment:

• hives, difficulty breathing or swallowing, swelling of the face, throat, tongue, lips, or eyes, hoarseness
• unusual muscle pain, trouble breathing, stomach pain, nausea, vomiting, feeling cold especially in your arms or legs, feeling dizzy or lightheaded, extreme tiredness or weakness, fast or irregular heartbeat
• yellowing of skin or eyes, dark urine, light colored stools, nausea, vomiting, loss of appetite, or pain, aching, or tenderness in upper right part of stomach
• decreased urination, swelling of legs
• bone pain, pain in arms or legs, bone fracture, muscle pain or weakness, joint pain
• ongoing pain that begins in the upper left or middle of the stomach but may spread to the back, nausea, vomiting (in children patients only)

Lamivudine and tenofovir may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location - one that is up and away and out of their sight and reach. http://www.upandaway.org

Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website http://goo.gl/c4Rm4p for more information.

What OTHER INFORMATION should I know?

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Keep a supply of lamivudine and tenofovir on hand. Do not wait until you run out of medication to refill your prescription.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: July 15, 2025.