Description of Efavir
Brand Name : EFAVIR
Active ingredient: Efavirenz
Manufactured by : Cipla Ltd.
Strength : 600mg
Dosage Form : Tablets
Packing : Pack of 30 Tablets
Efavir tablet in co administration with other drugs to treat the infection caused by HIV. Efavir will not curable or preventable HIV/AIDS. Efavir suppress the HIV replication of virus cell and despite the destruction of the immune system. Efavir may help to delay the problems arises from AIDS/HIV diseases. The medicine allowed to purchase only with doctors prescription.
Pharmacology of Efavir
MECHANISM OF ACTION: Efavi is an non nucleoside reverse transcriptase inhibitor that fight against HIV-1 and stops HIV-1 replication and RNA & DNA dependent polymerase activities.
ABSORPTION: Efavirenz (Efavir) , bioavailabilty is 42% and Peak plasma concentration is 3-5hr.
DISTRIBUTION:. Efavirenz (Efavir) is distributed in CSF, enter into breast milk and protein bound is 99%
METABOLISM: Efavirenz (Efavir) mainly metabolized inCYP3A4 and CYP2B and isoenzyme to inactive hydroxyl metabolite.
ELIMINATION: In Efavir excreted via urine(14-34%) and faeces is 16-61% while terminal half life is 52-76hr(single dose) and 40-55hr (multiple dose).
Indication of Efavir
In adult and childerns 3 months old / weight of 3.5kg, Efavir is used by combination with other antiretroviral regimens for the treatment of HIV-1 type(human immunodeficiency virus).
Dose & Dosage's of Efavir
Efavir co administration with other antiretrovirals dosage of 600mg once daily (capsule/tablet) and solution of 720mg once daily.
Efavir should administrated with empty stomach, preferably bedtime.
Side Effects of Efavir
Rash and erythema multiforme
CNS effects like dizziness, headache, insomnia, somnolence, abnormal dreams, fatigue, impaired concentration.
Nausea, less frequently, vomiting, diarrhoea, hepatitis, depression, anxiety, psychosis, amnesia and ataxia, stupor, abdominal pain, liver failure, pancreatitis, convulsions, gynaecomastia, pruritus, blurred vision.
Contraindication of Efavir
Concurrent use with terfenadine, astemizole, cisapride, midazolam, triazolam, pimozide, bepridil or ergot alkaloids (ergotamine) causes hypersensitivity, severe hepatic impairment, lactation in patient.
Drug Interaction of Efavir
Efavir 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
Efavir with voriconazole ,plasma concentrations of efavirenz is high and voriconazole is decreased when given continusily.
Serious, life-threatening events (e.g. cardiac arrhythmias, respiratory depression) may produce when Efavir given with terfenadine, astemizole, cisapride, midazolam, triazolam, pimozide, bepridil or ergot alkaloids (ergotamine)
Precaution of Efavir
Monitor the patients with these problems and inform the healthcare providers:
* cholesterol and triglycerides.
* LFTs in patients with history of hepatitis B and/or C.Hepatic Function Use.
* Convulsions Use with caution in patients with history of seizures..
* CNS symptoms
* Redistribution/accumulation of body fat, including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement..
* Liver enzymes in patients with suspected past of hepatitis B or C infection and liver toxicity.
* Immune reconstitution syndrome . Lipids Increases in total cholesterol and triglycerides have been checked, Monotherapy Resistant virus may emerge rapidly.
* Psychiatric symptoms psychiatric disorders may be at greater risk. There have been occasional reports of death by suicide, delusions, and psychosis-like behavior.
* Skin rash Reported in 26% of adults and 46% of children.
* Overdosage Symptoms Increased CNS symptoms, involuntary muscle contractions.
Usage & Safety profile of Efavir Pregnancy & Lactation
Efavirenz has category D: Based on adverse effects by investigation and experience studies in humans a positive identification of human fetal risk is reported.
Storage of Efavir
Efavir store in a closed container at room temperature, kept away the medicine (Efavir) from heat, moisture, and direct light. Keep from freezing and reach of children. Do not use after expiry date. Ask your consultant about how should dispose of any medicine you do not use .