Emtricitabine is an antiretroviral for HIV (human immunodeficiency virus) infection. It belongs to the group of drugs called nucleoside reverse transcriptase inhibitors (NRTIs). This was the first class of medicines used in treating HIV infection. It is available for use in the form of hard capsules (200mg) and oral solutions (10mg/ml).

FDA Approval History:
For HIV infection- July 2, 2003

Uses

Emtricitabine is usually indicated as a part of combination therapy. It is indicated for use in patients with HIV-1 infection. The drug must not be used with lamivudine-containing medicines. This is because of the risk of severe interaction.

Working

Like other living beings, the human immunodeficiency virus has its life cycle. The virus replicates in the following way.

Since Emtricitabine is an NRTI, it interferes with the mechanism of reverse transcription. The steps below explain the working of such a drug.

• Reverse transcription
  During viral replication, reverse transcription plays a critical role. It uses an enzyme called reverse transcriptase to make copies of DNA from RNA.
• Emtricitabine enters
  Experts believe that this drug causes chain termination. It does so after the incorporation into the DNA of the virus. This helps in the inhibition of the reverse transcription process.
• A decrease in HIV load
  When the drug inhibits the process of viral replication, a decrease in total viral load is expected. However, this cannot occur in the blink of an eye. The viral load may decrease eventually.

Side Effects

The use of Emtricitabine may cause adverse effects during the treatment period. Patients administering this drug may experience the following or other reactions. Most side effects may be manageable. Though, it is advised to contact a doctor in moderate to severe cases.

Common side effects

• Loss of appetite
• Diarrhea
• Chills
• Cough
• Stomach pain
• Nausea
• Nasal congestion
• Runny nose
• Headache
• Unusual bruising
• Nasal congestion
• Difficulty in breathing
• Pale skin

Rare side effects

• Bloody urine
• Vomiting
• Increased appetite
• Dry skin
• Increased thirst
• Blurred vision
• Dry mouth
• Weight loss
• Sweating

Incidence not known

• Stabbing pain
• Dizziness
• Trouble concentrating
• Skin rash
• Stomach discomfort
• Loss of interest
• Indigestion
• Irritability
• Muscle pain
• Difficulty in moving
• Joint pain with swelling

Warnings and Precautions

• Pregnancy
  This drug may not be indicated for use in pregnant females unless clearly needed. If prescribed, the patients must be made aware of the potential risks.
• Nursing
  Patients who are breastfeeding a baby must not administer this drug and vice versa. This is relevant due to an increased risk of transmission of the virus and the medicine to the baby.
• Lactic Acidosis
  Clinicians link the symptoms of lactic acidosis with the use of this drug. These may include muscle aches, rapid breathing, burning sensation, and stomach pain. Regular monitoring and dose changes may be needed in serious cases.
• Patients with HBV & HIV-1 both
  Before prescribing antiretroviral therapy (ART), the doctor may recommend testing for hepatitis B virus infection. This drug has not yet been approved to treat patients who have both infections. People co-infected with hepatitis B and HIV may not be prescribed this drug.
• Severe Renal Impairment
  Since this drug is eliminated primarily via the kidney, kidney patients may require dose changes.

Interactions

Some factors can cause interactions during antiretroviral therapy. Below are some of the common drugs and diseases that can interact with Emtricitabine.

• Interaction with medicines
  Drugs such as lamivudine, zalcitabine, levoketoconazole, teriflunomide, leflunomide, mipomersen, lomitapide, and pexidartinib may cause moderate to severe interactions with Emtricitabine. Besides these, there are other drugs that can interact and cause mild side effects.
• Interaction with diseases
  The use of medicine in patients with hepatitis B virus infection, hemodialysis, or renal dysfunction may result in the occurrence of a few side effects. This is because the diseases can interact with Emtricitabine.
• Interaction with food/alcohol
  Emtricitabine may interact with alcohol. This is why doctors ask the patients to avoid alcohol consumption during most HIV therapies. Such interactions may lead to side effects like dizziness, stomach pain, etc.

Overdose

The recommended dose of Emtricitabine varies with respect to the age and weight of the patient. Also, this medicine comes in two dose forms: Capsules and Oral Solutions. Below are the daily dosage details as reviewed by experts.

Patients aged above 18 years (Adults)

• Capsules: Single 200mg capsule
• Oral solution: 240mg (24ml)

Patients between 3 months and 17 years of age

• Capsules: Single 200mg capsule in children weight above 33kg
• Oral solution: 6 mg/kg, not more than 240mg (24ml)

Patients aged between 0 to 3 months (Pediatrics)

• Oral solution: 3mg/kg

In case of an overdose on Emtricitabine, experts advise monitoring the patients for toxicity symptoms. In moderate cases, standard supportive therapy may be provided by the doctors. Severe cases may require hemodialysis that can potentially remove up to 30% of the drug. Clinicians aren’t sure whether an overdose condition can be managed using peritoneal dialysis.

NOTE: Do not consider this information as a substitute for any medical prescription/advice. Kindly consult your doctor before taking this drug.