Truvada - How to use | Interaction | Effects
Truvada is a medication that contains two active substances (tenofovir and emtricitabine), and is classified into a group of antiviral drugs used for the treatment of HIV infection. These two drugs exert synergistic antiviral activity against HIV-1 virus. Both active pharmaceutical ingredients are phosphorylated in the body and their tendency for the binding to a human DNA polymerase is very low, which means that this drug exhibits fewer side effects than other antiretroviral drugs.
This medicine is used to treat patients who are older than 18 years old and are infected with HIV-1 virus.
To date, this drug is not approved for the treatment of chronic hepatitis B.
Tenofovir and emtricitabine are excreted by the kidneys, and it is necessary to monitor the kidney function (creatinine clearance) before starting the treatment, then two times during the first month of treatment. After first month, kidney function should be monitored once every three months. There have been reports of serious kidney damage in patients taking this drug. Concomitant administration with nephrotoxic drugs (e.g. NSAIDs) should be avoided.
Lactic acidosis, pathological accumulation of fat in the liver and consequent enlargement of the liver with severe health consequences (including death) have also been reported in patients who are taking Truvada. Considering that enlarged liver causes no recognizable symptoms, as it does not contains nerves that will send signals to the brain that something is wrong, it is very important to control liver function routinely at each doctor visit.
Truvada reduces bone mineral density, but clinical significance of this undesirable effect has not been established, since clinical studies have shown no increased incidence of bone fracture in patients who are treated with this drug.
Although it is proven that use of this drug reduces the risk of HIV transmission through sexual contact, the risk still exists. Therefore, patients who are treated with this drug should bear in mind that they can still infect others.
It should not be administered in combination with other medicinal products that contain emtricitabine or tenofovir. Co-administration with lamivudine is also contraindicated.
Truvada, pregnancy and breastfeeding
Truvada is classified in group B because the available clinical data from about 1,000 pregnancies showed that this drug does not increase the incidence of major birth defects. Manufacturer states that this medication can be used during pregnancy if necessary.
Truvada is excreted into breast milk. Breastfeeding should be certainly avoided because of the possible transmission of the virus through milk.
How to use
The recommended dose is one tablet (245 mg of emtricitabine + 200 mg of tenfovir) per day with meals.
Truvada should not be administered concurrently with the following drugs:
- Lamivudine (a drug that is also used for the treatment of HIV infection). Concomitant administration with this medication can cause antagonistic effect and to diminish effects of both drugs.
- Didanosine (a drug that is also used for the treatment of AIDS). Truvada significantly increases the concentration of didanosine in the blood which can cause inflammation of the pancreas and lactic acidosis.
Concomitant use with following drugs increases the risk of acute kidney injury:
- Adefovir (a drug used for the treatment of chronic hepatitis B)
- Non-steroidal anti-inflammatory drugs, such as:
- Zoledronic acid - a drug used for the prevention of osteoporosis.
- Mesalamine - a drug used to treat ulcerative colitis
Antibiotics, such as:
Truvada may cause following side effects:
- Increased blood glucose levels
- Increased levels of triglycerides in the blood
- Decreased levels of phosphate in the blood
- Decreased levels of potassium in the blood
- Decrease in the number of white blood cell
- Pain in the stomach
- Lactic acidosis
- Increased urinary protein excretion
- Acute renal failure
- Abnormal dreams
- Depressed mood
- Genital ulcers