Trade name : Estiva
Active ingredient : Efavirenz
Strength availability : 600mg
Manufactured by : Hetero
Dosage Form : Tablets
Package : 30 tablets
Efavirenz is sold under the brand name Estiva and belongs to antiretroviral medication. Estiva tablet in concomitant use with other drugs to treat the infection caused by HIV. Estiva suppress the HIV replication of virus cell and despite the destruction of the immune system. Estiva may help to delay the problems arises from AIDS/HIV diseases. Estiva will not curable or preventable HIV/AIDS. The drug is prescription medicine provided under the guidance of medical practioners
Estiva tablets are anti-retroviral drug which is used in HIV infection, by combining with other anti-retroviral drugs used in adult and children’s 3 months old / weight of 3.5kg
The pharmacology of Efavirenz is similar to lamivudine. Efavirenz is show activity by prohibiting the activity of viral RNA directed DNA polymerase enzyme which is a reverse transcriptase. The alteration occurs intracellularily to form active triphosphorylated which is specific for the activity of Efavirenz. The phosphorylation occurs based up on the cell type,. The production of DNA duplicates of viral RNA is mediate by inhibition of reverse transcriptase. This generation is necessary for production of new viral assembly. Finally the prohibition causes cell division termination.
The normal advice recommended dose of Estiva in adults is 600mg of tablet should be administered orally as a single dose by combining with protease inhibitors or nucleoside analogue reverse transcriptase inhibitors.
The Efavirenz concentration of should be elevated when the Estiva tablet should be administered with food which leads to increase the adverse effects associated to Estiva.
The up take drug at bed time should elevate the tolerability of nervous system symptoms.
Dose alteration :
Concomitant use of Estiva with voriconazole, the continuance dose of voriconazole should be elevated to 400mg for every 12 hours and the Estiva dose should be depletes to 300mg as a single dose. Estiva tablets should not be broke, chew or crush. In combination with rifampin, the dose of Estiva is 800mg.
In pediatrics :
The dose of Estiva should be suggested for the pediatric patients with the age of 3 years. 10 to < 15kg: given 200mg of Efavirenz 15 to <20kg: given 250mg of Efavirenz 20 to <25kg: given 300mg of Efavirenz 25 to <32.5kg: given 350mg of Efavirenz 32.5 To <40kg: given 400mg of Efavirenz At least 40kg: given 600mg of Efavirenz
ABSORPTION: Efavirenz has time to Peak plasma concentration is 3-5hr and bioavailabilty is 42%
DISTRIBUTION: Efavirenz (Estiva) has human protein bound is 99% and distributed in CSF, enter into breast milk.
METABOLISM: Efavirenz (Estiva) mainly metabolized inCYP3A4 and CYP2B and isoenzyme to inactive hydroxyl metabolite.
ELIMINATION: In Estiva excreted via urine(14-34%) and faeces is 16-61% while terminal half life is 52-76hr(single dose) and 40-55hr (multiple dose).
Check the patients with these problems and inform the healthcare providers: Cholesterol and triglycerides. Redistribution/accumulation of body fat, including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement.. LFTs in patients with history of hepatitis B and/or C.Hepatic Function Use. Immune reconstitution syndrome. Lipids Increases in total cholesterol and triglycerides have been checked, Monotherapy Resistant virus may emerge rapidly. Convulsions Use with caution in patients with history of seizures.. CNS symptoms Liver enzymes in patients with suspected past of hepatitis B or C infection and liver toxicity. Psychiatric symptoms psychiatric disorders may be at greater risk. Some occasional reports of death by suicide, delusions, and psychosis-like behavior. Skin rash Reported in 26% of adults and 46% of children. Over dosage Symptoms Increased CNS symptoms, involuntary muscle contractions.
Estiva with psychoactive drugs leads to additive CNS effects and change plasma warfarin concentrations with warfarin. Interaction with HIV integrase inhibitors (dolutegravir), other HIV NNRTIs ( etravirine), HMG-CoA reductase inhibitors ( simvastatin) reduce plasma concentration Estiva with voriconazole ,plasma concentrations of Efavirenz is high and voriconazole is decreased when given continuity. Serious, life-threatening events (e.g. cardiac arrhythmias, respiratory depression) may produce when Estiva given with terfenadine, astemizole, cisapride, midazolam, triazolam, pimozide, bepridil or ergot alkaloids (ergotamine)
Hypersensitivity reactions are produced due to patients may contraindicate to the components present in the Estiva tablets. Contraindicated drugs like; Due to this effect, patients may affect with severe life threatening conditions. Avoid the combinational therapy. Some of the drugs are given below; Anti-migraine like ergot derivatives Benzodiazepines Calcium channel blockers GI motility agents Neuroleptics St John’s wort
If missed to take a dose, leave the dose and take your next dose at the normal time or take it as soon as you remember and take your next dose at the normal time. Do not have the extra dose to make up for a missed dose. Please consult with the doctor.
Nervous system symptoms,
Lab abnormalities :
Elevation of AST, ALT, Elevation amylase, Increased glucose level, Neutropenia. The common side effects of efavirenz are :
Anorexia, Nausea, Vomiting , Diarrhea, Dyspepsia, Abdominal pain, Anxiety, Fatigue, Pain, Dizziness, Headache, Insomnia, Abnormal dreams, Depression. Post marketing :
Allergic reactions, Fat redistribution, Ataxia, Convulsions, Hyposthenia, Paresthesia, Neuropathy, Tremor, Vertigo, Gynecomastia, Constipation, malabsorption, Palpitations, An increased hepatic enzyme leads to hepatic failure, Hypercholestremia, Dyspnea, Abnormal in vision.