When Is Tenofovir Used?
Tenofovir is the trade name of the medicine Tenofovir disoproxil, a synthetic antiviral drug that is pharmacologically classified as a nucleoside reverse transcriptase inhibitor. This drug was synthesized in the Czech Republic in the mid-1980s, and in 1997, American scientists proved the effectiveness of Tenofovir against HIV in humans. Tenofovir was originally administered subcutaneously and later became available for oral administration. In addition to treating HIV infection, Tenofovir is also used in the treatment of chronic viral hepatitis B. The FDA approved Tenofovir for the treatment of HIV in 2001 and for the treatment of hepatitis B in 2008.
To date, Tenofovir is available in tablets for oral administration at a dosage of 300 mg of the active ingredient in one tablet. Tablets are film-coated light blue in color, they are oval, biconvex, on the cross section they have a white or almost white, slightly yellowish color. Excipients (magnesium stearate, pregelatinized starch, microcrystalline cellulose, lactose monohydrate and croscarmellose sodium), as well as a number of dyes and fixatives that form a film coating, don’t affect the effect of the drug.
When Is Tenofovir Contraindicated?
The main contraindication to the use of Tenofovir is hypersensitivity to this drug. Unfortunately, it is possible to determine whether a patient has it only by experience.
Partial contraindications include use during pregnancy and lactation, use in case of impaired renal function, as well as while taking Tenofovir with certain other drugs. Patients with renal insufficiency, including those on hemodialysis, should use Tenofovir with caution and under the supervision of a physician. If necessary, the interval between the administration of the drug can be adjusted. The risk of developing or progressing kidney failure can be managed by monitoring blood tests, especially indicators such as creatinine clearance and serum phosphorus.
The use of Tenofovir simultaneously or shortly after treatment with nephrotoxic drugs should be avoided, as this may lead to an excessive burden on the urinary system.
Tenofovir Side Effects
Side effects that occur as a result of taking Tenofovir are observed mainly from the side of metabolism, the digestive system and the nervous system. So, on the part of metabolism, many patients experience such a condition as hypophosphatemia, less often – hypokalemia. The digestive system quite often responds to the drug with diarrhea, vomiting and nausea, flatulence. Patients with pancreatic disease may develop pancreatitis and an increase in transaminase activity. The nervous system reacts to taking Tenofovir with dizziness, and the urinary system – with worsening of existing renal failure, the development of proximal renal tubulopathy (including Fanconi’s syndrome).
Dosages
Tenofovir is taken with or without food. The recommended dosage is 300 mg once daily. It is necessary to strictly observe the time of taking the medicine so that it is the same every day (plus or minus 1 hour). This is necessary so that the active substance is in the blood at a stable concentration. However, the optimal dosing regimen for a particular patient is always determined by the doctor, so self-administration of the drug is unacceptable.
If the patient suffers from renal insufficiency, then, depending on the results of the analysis for creatinine clearance, a dosage of 300 mg is taken either every 48 hours, or every 72 hours, or every 96 hours. Patients on hemodialysis receive 300 mg tenofovir every 7 days after dialysis is completed.4
Tenofovir disoproxil is the active ingredient of not only the branded drug Tenofovir, but also many of its generics. The original drug is very expensive and affordable for few consumers, so its generics are very popular both in the US and in other countries. Tenofovir generics, in addition to the 300 mg dosage, are also available in 600 mg dosages. In this case, the tablet must be divided into two parts before taking. This may not seem like a very convenient option, but it saves an additional amount, since in this case one half-tablet dosage is cheaper than a separate 300 mg tablet.
How To Buy Tenofovir Online
Buying Tenofovir online is a convenient option to save money, since drugs based on tenofovir disoproxil fumarate in online pharmacies traditionally cost significantly less than in conventional pharmacies. In addition, online pharmacies offer consumers a wide range of generic drugs to control HIV infection, including Tenofovir. The price of Tenofovir generics from Indian manufacturers, whose products are one of the most popular on the world pharmaceutical market, is many times lower than the cost of the original drug. So, tenofovir disoproxil fumarate 300 mg price from the Indian pharmaceutical company HETERO (https://www.hetero.com/) is only about 60 cents per tablet, so a monthly supply of the drug will cost a little more than $30.
There are other offers, and among them you can find even more profitable ones, especially when buying a large number of tablets in one order. You can make a purchase on the websites of international, as well as large foreign online pharmacies. US residents who order Tenofovir online with delivery to their local post office usually receive the medication 7-10 days after ordering.
