Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Emtriva. If you are concerned about side effects, discuss the risks and benefits of Emtriva with your doctor.

The following side effects have been reported by at least 1% of people taking Emtriva. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abnormal dreams
• cough
• Diarrhea
• difficulty sleeping
• dizziness
• headache
• muscle pain
• nausea
• prickly, tingling, burning sensations
• rash
• runny nose
• skin discoloration, especially of the palms of the hands and soles of the feet
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• symptoms of liver problems (e.g., yellowing of the skin or eyes, dark urine, pale stools, loss of appetite, nausea, and lower stomach pain)

Seek immediate medical attention if any of the following occur:

• symptoms of lactic acidosis (e.g., nausea, vomiting, unusual muscle pain, stomach pain, weakness, tiredness, feeling cold, dizziness, lightheadedness, or irregular heartbeat)

Each hard gelatin size 1 capsule with a blue cap and white body, printed with "200 mg" in black on the cap and "GILEAD" and the corporate logo in black on the body, contains emtricitabine 200 mg. Nonmedicinal ingredients: crospovidone, magnesium stearate, microcrystalline cellulose, and povidone.

Do not use Emtriva if you are allergic to emtricitabine or to any of the ingredients of the medication.

There may be an interaction between emtricitabine and any of the following:

• Ganciclovir
• lamivudine
• other products that contain emtricitabine
• ribavirin
• tenofovir
• valganciclovir
• zidovudine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Emtriva.

Fat redistribution: Emtriva may change how fat is distributed on your body. With long-term use, fat may accumulate on the stomach, back, and breasts and be reduced on the arm, legs, and face. Notify your doctor if you start developing any changes in your body's appearance.

Hepatitis B: The safe use of Emtriva for people who are also infected with hepatitis B has not been established. Your doctor may test you for hepatitis B infection before starting you on Emtriva. If Emtriva is used to treat HIV for people who also have hepatitis B, worsening of hepatitis B may occur. If you have hepatitis B and stop taking Emtriva, your hepatitis may return more severely than before. Do not stop taking Emtriva unless recommended by your doctor. Your doctor will monitor your liver function closely while you are taking emtricitabine.

Immune reconstitution syndrome: Emtriva may cause immune reconstitution syndrome, where signs and symptoms of inflammation from previous infections appear. These symptoms occur soon after starting anti-HIV medication and can vary. They are thought to occur as a result of the immune system improving and being able to fight infections that have been present without symptoms (such as pneumonia, herpes, hepatitis, or Tuberculosis). Report any new symptoms to your doctor immediately.

Lactic acidosis and enlarged liver: Emtriva can cause a rare but serious condition called lactic acidosis (buildup of lactic acid), together with an enlarged fatty liver. You may be more likely to experience these problems if you are female, obese, or have been taking nucleoside analog medications such as emtricitabine for a long time. Seek immediate medical attention if you notice any symptoms of this condition, such as:

• dizziness
• feeling cold
• irregular heartbeat
• lightheadedness
• nausea
• stomach pain
• tiredness
• vomiting

Liver problems: Emtriva can cause liver problems. Your doctor may monitor your liver function while you are taking Emtriva, especially if you have risk factors for liver problems. Tell your doctor immediately about any signs of liver problems, such as:

• dark urine
• diarrhea
• loss of appetite
• nausea
• pale stools
• vomiting
• weight loss
• yellowing of the skin or whites of the eyes

Reduced kidney function: Emtriva is primarily eliminated from the body by the kidneys. People with reduced kidney function will need longer than 24 hours between doses. Your doctor will recommend how you should take Emtriva based on your kidney function.

Pregnancy: The medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Emtriva, contact your doctor immediately.

Breast-feeding: Emtricitabine passes into breast milk. Breast-feeding is not recommended for HIV-positive women since the virus can be passed to the baby through breast milk.