BMA Concise Guide to Medicine & Drugs

Emtricitabine

Brand name Emtriva

Used in the following combined preparations Atripla, Stribild, Truvada

QUICK REFERENCE

Drug group Drug for HIV and immune deficiency

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic No

GENERAL INFORMATION

Emtricitabine is an antiviral drug used to treat (but not cure) HIV. It is a type of drug known as a nucleoside reverse transcriptase inhibitor, which blocks the enzyme reverse transcriptase that HIV needs to replicate. In treating HIV infection, emtricitabine is usually used in combination with other anti-HIV drugs to reduce production of new viruses before the immune system is irreversibly damaged. This combined therapy (highly active antiretroviral therapy, or HAART) reduces the viral load in people with HIV but does not completely rid the body of the virus. HIV may still be transmitted to other people and so it is important to continue taking precautions to avoid infecting others.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Capsules, oral solution.

Frequency and timing of doses Once daily. Swallow capsules whole with water. If you vomit within 1 hour of a dose, take another one; if you vomit more than 1 hour after a dose, do not take another one.

Adult dosage range 200mg daily for those weighing more than 33kg. Reduced dose for those weighing less.

Onset of effect May take from many weeks to a year before the drug reduces virus levels significantly.

Duration of action Up to several days.

Diet advice None.

Storage Keep in original container at room temperature and out of the reach of children.

Missed dose Take the missed dose as soon as you remember unless your next dose is due within 12 hours, in which case omit the missed dose and take the next dose as scheduled.

Stopping the drug Do not stop the drug without consulting your doctor; your condition may worsen.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. However, a large overdose may cause serious side effects; notify your doctor immediately.

POSSIBLE ADVERSE EFFECTS

Emtricitabine may cause a wide variety of adverse effects. The most common are headache, diarrhoea, nausea, muscle aches, and dizziness. Other possible side effects include rash, darkening of the skin, and redistribution of body fat. Consult your doctor if any of these are severe or if you develop fever, sore throat, tiredness, lethargy, or joint stiffness or pain. If you experience rapid breathing or drowsiness, contact your doctor promptly. Long-term use may also affect blood sugar and lipid levels and bone problems (see Prolonged use).

INTERACTIONS

General note Various drugs that affect the kidneys may affect blood levels of emtricitabine. Discuss with your doctor before taking any other medications.

Lamivudine and zalcitabine should not be used with emtricitabine because all three drugs are chemically similar and there is therefore a risk of increased toxicity.

Orlistat may reduce absorption of emtricitabine.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have kidney or liver disease.

· You have diabetes.

· You have a high blood cholesterol level.

· You are pregnant or intend to become pregnant.

· You are taking other medicines, especially corticosteroids.

Pregnancy Safety not established. Discuss with your doctor.

Breast-feeding It is not known if this drug passes into breast milk. However, HIV can be passed to the baby in breast milk so breast-feeding is not recommended.

Infants and children Not recommended under 4 months.

Over 60 No known problems.

Driving and hazardous work Avoid such activities until you have learned how the drug affects you because it may cause dizziness.

Alcohol Avoid. Alcohol increases the risk of developing serious bone problems.

PROLONGED USE

Emtricitabine as part of HAART therapy may cause redistribution of body fat and abnormal blood sugar and lipid levels. Rarely, it may also cause bone destruction, especially in the hip.

Monitoring Liver function tests are routine and people being treated for HIV will have additional regular checks of blood cell counts (including CD4 counts), viral load, blood sugar and cholesterol levels, and response to treatment.