Tenofovir || Mechanism of action of tenofovir || HIV teatment

Tenofovir: use , side effect , mechanism of action , price


Tenofovir is use for the treatment of Human immunodeficiency virus (HIV) .it use as single content and combination dose with other content . it is avalabe in the salt form as Tenofovir Disoproxil fumarate . it also use for the for hepatitis B .it cure the hepatitis B completely if you take proper dose as per doctor instruction.

Tenofovir 300 mg tablets
Tenofovir 300 mg Tablets

Tenofovir side effect

It produce few side effect like nausea,vomiting, pain , feaver,  flatulence, abdominal discomfort, loose motions and headache. Some most importance but less side effect are renal toxicity, slightly increase in serum creatinine .  skin rash is occour some time.

Tenofovir mechanism of action

Tenofovir is comes under Nucleoside reverse transcriptase inhibitor. Tenofovir is use as prodrug use as disoproxil ester. Tenofovir is also known as acyclic nucleoside phosphonate  diiaster analog of adenosine monophosphate. As you know it is prodrug it converted to tenofovir diaphosphate in the presence of enzyme.

When virus capsid enter into cell,viral plasmid are disoved . RNA OF virus are are in the cell .here enzyme nucleoside reverse transcriptase are act on this work . this enzyme having RNA depended DNA polymerase which is help to produce complimentary nucleotides  and DNA strand are made. Other domain of Nucleoside reverse transcriptase are destroy the Parent virus RNA .so domain of DNA are free for make fully double strand DNA . DNA polymerase are made with nucleotide which having hydroxyl group , combination of hydroxyl group are create chain.
HIV virus structure
HIV virus structure

Tenofovir is enters into the viral DNA and there are changes of  stop the DNA Polymerase chain creation .Tenofovir has very low affinity towards the host DNA polymerase .
For more information about HIV virus replication you must read my previous post.

Absorption of tenofovir

Tenofovir has very low absorption capacity . some study fasting patient tenofovir bioavailability is 25%. Tenofovir Disoproxil fumarate is pro drug of tenofovir which is more water soluble in nature. If a fasted patient is taken Tenofovir disoproxil fumarate 300 mg for the treatment of HIV 1 virus maximum serum concentration are achive in 1 hour. It is not complete absolved in our body but required amount is absolved if you take orally. Tenofovir is absorption is increases if you take it with food .high fat contain food is increase 1 hour cmax vale as compaired to the fasted stage.

Plasma binding capacity of tenofovir is less than 0.7 and 7.2 % respectively.
Tenofovir metabolism enzyme is not known clearly . but it not metabolize by the cytochrome P450 or substrate. It elimination is mainly ocours in urine .about 80% is eliminate as unchanged form within 70 hours if patient is take tenofovir disoproxil fumarate 300 mg a day. Elimination is occour by glomerular filtration and active tubular secreation.


Dosage

For the treatment of HIV 1 and chronic hepatitis B Tenofovir disoproxil fumarate 300 mg oral dose is working good with food.

Pediatric patient below or with age 12 are take Tenofovir disoproxil fumarate 300 mg with food is working good for the treatment of HIV 1.

Patient which have kidney problem the dose of this medicine is same but frequency of dose is depend on the creatinine clearance .if  createine clearance is >50 then dose is taken every 24 hour, 30-49 ml/min then dose is taken every 48 hour.

For the hemodialysis patient there are no dose are selected .for the treatment contact your doctor.

Indication

Tenofovir are shown contraindication  with other HIV treatement drug .like tenofovir with emtricitabine or efaverinz , emtricitabine and tenofovir.
In Hepatitis B patient who take nucleoside –treatment navie or lamivudine compresttion with liver disease.

Some Precautions

Tenofovir causes lactic acidosis and severe hepatomegaly with steatosis when it take along with other nucleoside analogs or other antiretrovirals medicine. Mainly women are more affected with this lactic acidosis. When you take tenofovir excerise must doing regularly because it increase the obesity. Mainly it affect the liver so if persion having any lever problem please consult your doctor for taking advice.

If any persion are treatment of hepatitis B with tenofovir for long duration and he discontinue the medicine or stop taking medicine this persion are take observation for several month.
This medicine is mainly excreated through kidney so there are many chances of renal failure.


Interaction with other drug

Tenofovir when take with Didanosine it increases the adverse effect of didanosine .if the patient are take didanosine with this medicine and diadonosine adverse effect is increase the imidiately stop the medication .
Tenofovir structure
Tenofovir structure

This medicine increase the Cmax of didanosine. Mechanism is unknown.
This medicine also interaction with Atazanavir. Atazanavir is increase the absorption of tenofovir , mechanism is unknown. If the patient is take both of medicine then patient is take monitoring by doctor.

This medicine also interaction with lopinavir and ritonavir .lopinavir and ritonavir is increase the concentration of tenofovir. Mechanism of action is unknown.

This medicine is excreated by kidney so if any medicine is affect the renal system .tenofovir is interaction with this medicine.

Storage condition of Tenofovir

This medicine is store in the room temperature, which is 20°C to 25°C. Keep this medicine away form the children for the safety purpose. If the medicine box or pack is unseal then don’t take this medicine . container pack is containing  desiccant which is help prevent the moisture. Before taking this medicine check the expiry of box.

 Dosage form

Tenofovir sold in the market as viread which is manufacture by cipla .it is abribiated as TDF. And also some brand name tenvir . it is take as oral dosage form. It is also avalable in combination of medicine as name odumune tablets.

Price of the medicine

Price of Viread 300 mg tablets is 1379 rupees for 30 tablets in India. Which is given mylan pharmaceuticals pvt ltd.
Tenvir 300 mg tablets price is 1487.98 rupees for 30 tablets in India .which is manufacture by cipla.
This medicine is very costly.

History

Tenofovir is synthesize in 1984 by Antonin Holy in the institute of Organic and Biochemestry in prague. And its mechanism of action is describe in 1985.
   Tenofovir Disoproxil was approved in 2001 october 26 for treatement of HIV AIDS by USFDA . And again it approve by USFDA for Hepatitis B in the 2008 August 11.

Reference

Avobe this information is collected form Wikipedia and some medical books.


Tenofovir || Mechanism of action of tenofovir || HIV teatment Tenofovir || Mechanism of action of tenofovir || HIV teatment Reviewed by aboutmedicine on 20:52 Rating: 5

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