Home :: Drugs :: Efavirenz

Efavirenz - Learn about Efavirenz Side Effects and Precautions

Efavirenz Information

The pharmacology action of Efavirenz is that it noncompetitive inhibition of HIV-1 reverse transcriptase

Efavirenz is used in treatment of HIV-1 infection in combination with other antiretroviral agents.

Interaction and Contraindication of Efavirenz

Interaction of Efavirenz - Alprazolam, midazolam, triazolam:  May increase blood levels of these drugs, which may produce extreme sedation and respiratory depression. Do not administer concurrently.
Clarithromycin, indinavir, methadone, saquinavir:  Efavirenz may decrease plasma concentrations, which could reduce activity of these agents.
Cisapride, ergot derivatives:  May elevate levels of these drugs, which may increase the risk of arrhythmias, hematologic abnormalities, or other potentially serious adverse effects. Do not coadminister.
Ethinyl estradiol, nelfinavir, ritonavir:  Efavirenz may increase plasma concentrations, which could increase activity or toxicity of these agents.
Phenytoin, carbamazepine, phenobarbital:  Plasma concentrations of the anticonvulsant or efavirenz may decrease.
Rifampin:  May decrease plasma levels of efavirenz, which may reduce antiviral activity.
Ritonavir:  May increase efavirenz plasma level, which could increase side effects.
St. John's wort:  May reduce efavirenz plasma concentrations, which may decrease the clinical efficacy.
Warfarin:  Plasma concentrations may be increased or decreased

Contraindication of Efavirenz - Concomitant use with cisapride, ergot derivatives, midazolam, or triazolam; hypersensitivity to product.

Side Effects of Efavirenz

Here are the list of some common side effects of Efavirenz :

• Dizziness (28.1%); fatigue; headache; hypesthesia; impaired concentration (8.3%); insomnia (16.3%); abnormal dreams (6.2%); somnolence (7%); depression; anorexia; nervousness; ataxia; confusion; impaired coordination; paresthesia; neuropathy; tremor; agitation; emotional lability; hallucination; psychosis.
• Maculopapular rash; rash (26.3%; eg, blistering, desquamation, mucosal involvement, fever); pruritus; increased sweating.
• Abnormal vision; tinnitus.
• Nausea; vomiting; diarrhea; dyspepsia; abdominal pain
• Hepatitis; LFT elevation
• Increased total cholesterol; increased amylase
• Cough; dyspnea
• Arthralgia; myalgia; asthenia; fever; pain.

Precaution and Warning while taking Efavirenz

The precaution and warnings of Efavirenz drug is as follows:

• Inform patient not to alter the dose or discontinue therapy without consulting health care provider.
• Inform patient that efavirenz may cause dizziness, impaired concentration, or drowsiness, and to avoid potentially hazardous tasks such as driving or operating machinery if experiencing these symptoms.
• Inform patient that dosing at bedtime improves the tolerability of CNS symptoms.
• Alert patient to the potential for additive CNS effects when efavirenz is used concomitantly with alcohol or psychoactive drugs.
• Instruct patient to avoid OTC medications unless prescribed by primary health care provider.
• Caution patient or family that long-term effects and adverse effects are not known. Therefore, report any problems to the primary care provider.
• Warn patient of the potential adverse effects and drug/drug interactions.
• Instruct patient to notify health care provider immediately if signs of rash or rash accompanied by fever, blistering, oral lesions, conjunctivitis, swelling, muscle or joint aches, general malaise, infection such as a sore throat, fever, cough, or respiratory congestion occur.
• Instruct patient to notify health care provider immediately if symptoms of serious psychiatric adverse experiences occur.
• Inform patient of potential false-positive urine cannabinoid test results.
• Inform patient that efavirenz has not been shown to reduce the risk of passing HIV to others through sexual contact or blood contamination. Encourage abstinence or practicing safe sex and not sharing needles.
• Advise women to use barrier contraception in combination with other methods of contraception (eg, oral or other hormonal contraceptives).
• Caution mothers to discontinue nursing while receiving efavirenz as there is potential for adverse effects from the drug in nursing infants and transmission of the HIV virus.
• Advise women to inform health care provider if pregnant, planning to become pregnant, or breastfeeding.
• Stress the importance of regular exams and laboratory work.

How to store Efavirenz

• Store oral capsules and tablets at room temperature (77°F); excursions permitted (59° to 86°F).
• Administer on an empty stomach.
• Avoid high-fat meal, as it may increase absorption.
• Administer at bedtime initially and when CNS symptoms are present to improve tolerance of these symptoms.
• Always give in combination with other antiviral agents.
• Do not administer to nursing women.