Renal Impairment
HIV-1 seronegative adults with mild (CrCL 50-79 mL per min; n=7), moderate (CrCL 30-49 mL per min; n=6), or severe (CrCL less than 30 mL per min; n=4) renal impairment received a single 200 mg dose of nevirapine in a pharmacokinetic trial. These subjects did not require dialysis. The trial included six additional subjects with renal failure requiring dialysis.
In subjects with renal impairment (mild, moderate or severe), there were no significant changes in the pharmacokinetics of nevirapine. However, subjects requiring dialysis exhibited a 44% reduction in nevirapine AUC over a one-week exposure period. There was also evidence of accumulation of nevirapine hydroxy-metabolites in plasma in subjects requiring dialysis. An additional 200 mg dose following each dialysis treatment is indicated [see Dosage and Administration (2.4) and Use in Specific Populations (8.6)].
Hepatic Impairment
In a steady-state trial comparing 46 subjects with mild (n=17; expansion of some portal areas; Ishak Score 1-2), moderate (n=20; expansion of most portal areas with occasional portal-to-portal and portal-to-central bridging; Ishak Score 3-4), or severe (n=9; marked bridging with occasional cirrhosis without decompensation indicating Child-Pugh A; Ishak Score 5-6) fibrosis as a measure of hepatic impairment, the multiple dose pharmacokinetic disposition of nevirapine and its five oxidative metabolites were not altered. However, approximately 15% of these subjects with hepatic fibrosis had nevirapine trough concentrations above 9,000 mcg per mL (2-fold the usual mean trough). Therefore, patients with hepatic impairment should be monitored carefully for evidence of drug-induced toxicity [see Warnings and Precautions (5.1)]. The subjects studied were receiving antiretroviral therapy containing nevirapine 200 mg twice daily for at least 6 weeks prior to pharmacokinetic sampling, with a median duration of therapy of 3.4 years.
In a pharmacokinetic trial where HIV-1 negative cirrhotic subjects with mild (Child-Pugh A; n=6) or moderate (Child-Pugh B; n=4) hepatic impairment received a single 200 mg dose of nevirapine, a significant increase in the AUC of nevirapine was observed in one subject with Child-Pugh B and ascites suggesting that patients with worsening hepatic function and ascites may be at risk of accumulating nevirapine in the systemic circulation. Because nevirapine induces its own metabolism with multiple dosing, this single-dose trial may not reflect the impact of hepatic impairment on multiple-dose pharmacokinetics.
Do not administer nevirapine to patients with moderate or severe (Child-Pugh Class B or C, respectively) hepatic impairment [see Contraindications (4), Warnings and Precautions (5.1), and Use in Specific Populations (8.7)].
Gender
In the multinational 2NN trial, a population pharmacokinetic substudy of 1077 subjects was performed that included 391 females. Female subjects showed a 13.8% lower clearance of nevirapine than did men. Since neither body weight nor Body Mass Index (BMI) had an influence on the clearance of nevirapine, the effect of gender cannot solely be explained by body size.
Race
An evaluation of nevirapine plasma concentrations (pooled data from several clinical trials) from HIV-1-infected subjects (27 Black, 24 Hispanic, 189 Caucasian) revealed no marked difference in nevirapine steady-state trough concentrations (median Cminss = 4.7 mcg/mL Black, 3.8 mcg/mL Hispanic, 4.3 mcg/mL Caucasian) with long-term nevirapine treatment at 400 mg per day. However, the pharmacokinetics of nevirapine have not been evaluated specifically for the effects of ethnicity.
Black subjects (n = 80/group) in Trial 1100.1486 showed approximately 30% to 35% higher trough concentrations than Caucasian subjects (250-325 subjects/group) in both immediate-release nevirapine and nevirapine extended-release treatment groups over 96 weeks of treatment at 400 mg per day.
Geriatric Subjects
Nevirapine pharmacokinetics in HIV-1-infected adults do not appear to change with age (range 18–68 years); however, nevirapine has not been extensively evaluated in subjects beyond the age of 55 years [see Use in Specific Populations (8.5)].
Pediatric Subjects
Pharmacokinetic data for nevirapine have been derived from two sources: a 48-week pediatric trial in South Africa (BI Trial 1100.1368) involving 123 HIV-1 positive, antiretroviral-naïve subjects aged 3 months to 16 years; and a consolidated analysis of five Pediatric AIDS Clinical Trials Group (PACTG) protocols comprising 495 subjects aged 14 days to 19 years.
BI Trial 1100.1368 studied the safety, efficacy, and pharmacokinetics of a weight-based and a body surface area (BSA)-based dosing regimen of nevirapine. In the weight-based regimen, pediatric subjects up to 8 years of age received a dose of 4 mg/kg once daily for two weeks followed by 7 mg per kg twice daily thereafter. Subjects 8 years and older were dosed 4 mg/kg once daily for two weeks followed by 4 mg/kg twice daily thereafter. In the BSA regimen, all pediatric subjects received 150 mg/m2 once daily for two weeks followed by 150 mg/m2 twice daily thereafter [see Use in Specific Populations (8.4) and Adverse Reactions (6.1)]. Dosing of nevirapine at 150 mg/m2 BID (after a two-week lead-in of 150 mg/m2 QD) produced geometric mean or mean trough nevirapine concentrations between 4-6 mcg per mL (as targeted from adult data). In addition, the observed trough nevirapine concentrations were comparable between the two dosing regimens studied (BSA- and weight-based methods).
The consolidated analysis of Pediatric AIDS Clinical Trials Group (PACTG) protocols 245, 356, 366, 377, and 403 allowed for the evaluation of pediatric subjects less than 3 months of age (n=17). The plasma nevirapine concentrations observed were within the range observed in adults and the remainder of the pediatric population, but were more variable between subjects, particularly in the second month of age. For dose recommendations for pediatric patients [see Dosage and Administration (2.2)].
Drug Interactions [see Drug Interactions (7)]
Nevirapine induces hepatic cytochrome P450 metabolic isoenzymes 3A and 2B6. Co-administration of nevirapine and drugs primarily metabolized by CYP3A or CYP2B6 may result in decreased plasma concentrations of these drugs and attenuate their therapeutic effects.
While primarily an inducer of cytochrome P450 3A and 2B6 enzymes, nevirapine may also inhibit this system. Among human hepatic cytochrome P450s, nevirapine was capable in vitro of inhibiting the 10-hydroxylation of (R)-warfarin (CYP3A). The estimated Ki for the inhibition of CYP3A was 270 micromolar, a concentration that is unlikely to be achieved in patients as the therapeutic range is less than 25 micromolar. Therefore, nevirapine may have minimal inhibitory effect on other substrates of CYP3A.
Nevirapine does not appear to affect the plasma concentrations of drugs that are substrates of other CYP450 enzyme systems, such as 1A2, 2D6, 2A6, 2E1, 2C9, or 2C19.
Table 5 (see below) contains the results of drug interaction trials performed with nevirapine and other drugs likely to be co-administered. The effects of nevirapine on the AUC, Cmax, and Cmin of co-administered drugs are summarized.
Table 5 Drug Interactions: Changes in Pharmacokinetic Parameters for Co-administered Drug in the Presence of Nevirapine (All interaction trials were conducted in HIV-1 positive subjects) |
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Co-administered Drug
| Dose of Co- administered Drug
| Dose regimen of Nevirapine
| n
| % change of co- administered drug pharmacokinectic parameters ( 90 % CI)
|
Antiretrovirals
| AUC
| Cmax
| Cmin
|
Atazanavir/ Ritonavira,d
| 300/100 mg QD day 4–13, then 400/100 mg QD, day 14–23
| 200 mg BID day 1-23. Subjects were treated with Nevirapine prior to trial entry.
| 23
| Atazanavir 300/100 mg ↓42 (↓52 to ↓29)
| Atazanavir 300/100 mg ↓28 (↓40 to↓14)
| Atazanavir 300/100 mg ↓72 (↓80 to ↓60)
|
| | | | Atazanavir 400/100 mg ↓19 (↓35 to ↑2)
| Atazanavir 400/100 mg ↑2 (↓15 to↑24)
| Atazanavir 400/100 mg ↓59 (↓73 to ↓40)
|
Darunavir/ Ritonavire
| 400/100 mg BID
| 200 mg BID
| 8
| ↑24 (↓3 to ↑57)
| ↑40 (↑14 to ↑73)
| ↑2 (↓21 to ↑32)
|
Didanosine
| 100-150 mg BID
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 18
| ⇔
| ⇔
| §
|
Efavirenza
| 600 mg QD
| 200 mg QD x 14 days; 400 mg QD x 14 days
| 17
| ↓28 (↓34 to↓14)
| ↓12 (↓23 to↑1)
| ↓32 (↓35 to ↓19)
|
Fosamprenavir
| 1400 mg BID
| 200 mg BID. Subjects were treated with nevirapine prior to trial entry.
| 17
| ↓33 (↓45 to↓20)
| ↓25 (↓37 to↓10)
| ↓35 (↓50 to ↓15)
|
Fosamprenavir /Ritonavir
| 700/100 mg BID
| 200 mg BID. Subjects were treated with nevirapine prior to trial entry.
| 17
| ↓11 (↓23 to ↑3)
| ⇔
| ↓19 (↓32 to ↓4)
|
Indinavira
| 800 mg q8H
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 19
| ↓31 (↓39 to ↓22)
| ↓15 (↓24 to ↓4)
| ↓44 (↓53 to ↓33)
|
Lopinavira,b
| 300/75 mg/m2
(lopinavir/ ritonavir)b
| 7 mg/kg or 4 mg/kg QD x 2 weeks ; BID x 1 week
| 12, 15c
| ↓22 (↓44 to ↑9)
| ↓14 (↓36 to ↑16)
| ↓55 (↓75 to ↓19)
|
Lopinavira
| 400/100 mg BID (lopinavir/ ritonavir)
| 200 mg QD x 14 days; 200 mg BID >1 year
| 22, 19c
| ↓27 (↓47 to ↓2)
| ↓19 (↓38 to ↑5)
| ↓51 (↓72 to ↓26)
|
Maravirocf
| 300 mg SD
| 200 mg BID
| 8
| ↑1 (↓35 to ↑55)
| ↑54 (↓6 to↑151)
| ⇔
|
Nelfinavira
Nelfinavir-M8 metabolite
| 750 mg TID
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 23
| ⇔
| ⇔
| ↓32 (↓50 to ↑5)
|
| | | | ↓62 (↓70 to↓53)
| ↓59 (↓68 to↓48)
| ↓66 (↓74 to ↓55)
|
Ritonavir
| 600 mg BID
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 18
| ⇔
| ⇔
| ⇔
|
Stavudine
| 30-40 mg BID
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 22
| ⇔
| ⇔
| §
|
Zalcitabine
| 0.125-0.25 mg TID
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 6
| ⇔
| ⇔
| §
|
Zidovudine
| 100-200 mg TID
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 11
| ↓28 (↓40 to ↓4)
| ↓30 (↓51 to↑14)
| §
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Other Medications
| AUC
| Cmax
| Cmin
|
Clarithromycina
| 500 mg BID
| 200 mg QD x 14 days 200 mg BID x 14 days
| 15
| ↓31 (↓38 to ↓24)
| ↓23 (↓31 to↓14)
| ↓56 (↓70 to ↓36)
|
Metabolite 14-OH- clarithromycin
| | | | ↑42 (↑16 to ↑73)
| ↑47 (↑21 to↑80)
| ⇔
|
Ethinyl estradiola
and
| 0.035 mg (as Ortho-Novum®
1/35)
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 10
| ↓20 (↓33 to ↓3)
| ⇔
| §
|
Norethindronea
| 1 mg (as Ortho-Novum®
1/35)
| | | ↓19 (↓30 to ↓7)
| ↓16 (↓27 to ↓3)
| §
|
Depomedroxy- progesterone acetate
| 150 mg every 3 months
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 32
| ⇔
| ⇔
| ⇔
|
Fluconazole
| 200 mg QD
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 19
| ⇔
| ⇔
| ⇔
|
Ketoconazolea
| 400 mg QD
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 21
| ↓72 (↓80 to↓60)
| ↓44 (↓58 to↓27)
| §
|
Methadonea
| Individual Subject Dosing
| 200 mg QD x 14 days; 200 mg BID ≥7 days
| 9
| In a controlled pharmacokinetic trial with 9 subjects receiving chronic methadone to whom steady-state nevirapine therapy was added, the clearance of methadone was increased by 3-fold, resulting in symptoms of withdrawal, requiring dose adjustments in 10 mg segments, in 7 of the 9 subjects. Methadone did not have any effect on nevirapine clearance.
|
Rifabutina
| 150 or 300 mg QD
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 19
| ↑17 (↓2 to ↑40)
| ↑28 (↑9 to↑51)
| ⇔
|
Metabolite 25-O- desacetyl-rifabutin
| | | | ↑24 (↓16 to ↑84)
| ↑29 (↓2 to↑68)
| ↑22 (↓14 to ↑74)
|
Rifampina
| 600 mg QD
| 200 mg QD x 14 days; 200 mg BID x 14 days
| 14
| ↑11 (↓4 to ↑28)
| ⇔
| §
|
Because of the design of the drug interaction trials (addition of 28 days of nevirapine therapy to existing HIV-1 therapy), the effect of the concomitant drug on plasma nevirapine steady-state concentrations was estimated by comparison to historical controls.
Administration of rifampin had a clinically significant effect on nevirapine pharmacokinetics, decreasing AUC and Cmax by greater than 50%. Administration of fluconazole resulted in an approximate 100% increase in nevirapine exposure, based on a comparison to historic data [see Drug Interactions (7)]. The effect of other drugs listed in Table 5 on nevirapine pharmacokinetics was not significant. No significant interaction was observed when tipranavir was co-administered with low-dose ritonavir and nevirapine.