Efavirenzdosage

2 DOSAGE & ADMINISTRATION

Efavirenz should be taken orally once daily on an empty stomach, preferably at bedtime.

Recommended adult dose: 600 mg.

With rifampin, increase efavirenz dose to 800 mg once daily for patients weighing 50 kg or more.

Pediatric dosing is based on weight.

2.1 Hepatic

Function Monitor hepatic function prior to and during treatment with efavirenz. Efavirenz is not recommended in patients with moderate or severe hepatic impairment (Child Pugh B or C). 2.2 Adults The recommended dosage of efavirenz is 600 mg orally, once daily, in combination with a protease inhibitor and/or nucleoside analogue reverse transcriptase inhibitors (NRTIs). It is recommended that efavirenz be taken on an empty stomach, preferably at bedtime. The increased efavirenz concentrations observed following administration of efavirenz with food may lead to an increase in frequency of adverse reactions. Dosing at bedtime may improve the tolerability of nervous system symptoms. Efavirenz capsules or tablets should be swallowed intact with liquid. Concomitant Antiretroviral Therapy Efavirenz must be given in combination with other antiretroviral medications. Dosage Adjustment If efavirenz is coadministered with voriconazole, the voriconazole maintenance dose should be increased to 400 mg every 12 hours and the efavirenz dose should be decreased to 300 mg once daily using the capsule formulation (one 200 mg and two 50 mg capsules or six 50 mg capsules). Efavirenz tablets must not be broken.. If efavirenz is coadministered with rifampin to patients weighing 50 kg or more, an increase in the dose of efavirenz to 800 mg once daily is recommended.

2.3 Pediatric

Patients It is recommended that efavirenz be taken on an empty stomach, preferably at bedtime. Table 1 describes the recommended dose of efavirenz for pediatric patients 3 months of age or older and weighing between 3.5 kg and 40 kg. The recommended dosage of efavirenz for pediatric patients weighing 40 kg or greater is 600 mg once daily. For pediatric patients who cannot swallow capsules, the capsule contents can be administered with a small amount of food or infant formula using the capsule sprinkle method of administration.

Table 1: Efavirenz Dosing in Pediatric Patients Patient Body Weight Efavirenz Daily Dose Number of Capsules a or Tablets b and Strength to Administer 3.5 kg to less than 5 kg 100 mg two 50 mg capsules 5 kg to less than 7.5 kg 150 mg three 50 mg capsule 7.5 kg to less than 15 kg 200 mg one 200 mg capsule 15 kg to less than 20 kg 250 mg one 200 mg + one 50 mg capsule 20 kg to less than 25 kg 300 mg one 200 mg + two 50 mg capsules 25 kg to less than 32.5 kg 350 mg one 200 mg + three 50 mg capsules 32.5 kg to less than 40 kg 400 mg two 200 mg capsules at least 40 kg 600 mg one 600 mg tablet OR three 200 mg capsules a Capsules can be administered intact or as sprinkles. b Tablets must not be crushed