Only CYP3A4 is inhibited by nevirapine at values far above those that are therapeutically relevant (Ki=270 μM)[1]. Nevirapine has been applied to tumors in a number of human cancer models as a re-differentiation agent. After 48 hours of treatment, nevirapine strongly reduces cell growth at all tested dosages (100, 200, 350, and 500 μM). Nevirapine dramatically raises the proportion of apoptotic cells when compared to control at a high dose (500 μM)[2]. In multiple cellular assays, nevirapine is a strong and specific inhibitor (IC50=10-100 nM) of the replication of a broad range of HIV-1 strains[3].

Nevirapine can be used with nucleoside HIV-1 reverse transcriptase inhibitors (e.g., didanosine, zidovudine, etc.) in combination. The FDA has approved the use of nevirapine in conjunction with HIV-1 protease inhibitors, such as saquinavir, ritonavir, indinavir, and so forth. In humans, 2-, 3-, 8-, and 12-hydroxynevirapine glucuronide conjugates are the main way that nevirapine is excreted in the urine[1]. All sexes of mice, rats, rabbits, monkeys, and chimpanzees fully absorb nevirapine. In all investigated animal species, nevirapine is substantially metabolized in both sexes[4]. When compared to the control, nevirapine (9 mg/kg, 18 mg/kg, and 36 mg/kg) significantly reduces the ulcer severity score and ulcer index[5].

Absorption, Distribution and Excretion
Nevirapine is readily absorbed (greater than 90%) after oral administration in healthy subjects and adults with HIV-1 infection. The absolute bioavailability in healthy adults following a single dose administration is 93 ± 9% (mean ± SD) for a 50 mg tablet and 91 ± 8% for an oral solution. Peak plasma nevirapine concentrations of 2 ± 0.4 mcg/mL (7.5 micromolar) were attained by 4 hours following a single 200 mg dose. Nevirapine tablets and suspension have been shown to be comparably bioavailable and interchangeable at doses up to 200 mg. When the oral tablet is given with a high-fat meal, the extent of absorption is compared to that of the fasted-state.
Thus cytochrome P450 metabolism, glucuronide conjugation, and urinary excretion of glucuronidated metabolites represent the primary route of nevirapine biotransformation and elimination in humans. Only a small fraction (<5%) of the radioactivity in urine (representing <3% of the total dose) was made up of parent compound; therefore, renal excretion plays a minor role in elimination of the parent compound.
1.21 ± 0.09 L/kg [apparent volume of distribution, healthy adults, IV] Nevirapine is capable of crossing the placenta and is found in breast milk.
Nevirapine readily crosses the placenta and has been found in breast milk. The CSF-plasma ratio for nevirapine is approximately 0.45.
Nevirapine is readily (more than 90%) absorbed following oral administration in healthy or HIV-infected adults. Absolute bioavailability of nevirapine in 12 healthy adults was 93% following administration of a single 30 mg tablet or 91% following administration of an oral solution of the drug. Peak plasma nevirapine concentrations average 2 ug/ml and are attained within 4 hours after a single 200 mg dose of the dose in adults. Following multiple doses, peak plasma nevirapine concentrations appear to increase linearly in the dosage range of 200-400 mg daily. Nevirapine dosage of 400 mg daily resulted in steady-state trough plasma concentrations of 4.5 ug/ml.
Widely distributed. Nevirapine is highly lipophilic and essentially is nonionized at physiologic pH. Nevirapine readily crosses the placenta and is distributed into breast milk. Nevirapine concentrations in the cerebrospinal fluid were 45% of the concentrations in plasma, which is a ratio that is approximately equal to the fraction not bound to plasma protein.
Nevirapine crosses the placenta in humans. In a limited number of HIV-infected pregnant women who received a single 100- or 200-mg oral dose of nevirapine 0.9-10.5 hours prior to delivery, cord blood concentrations of nevirapine were 74-123% of maternal serum concentrations and peak serum concentrations of the drug in the neonates of these women averaged 862 ng/mL (range: 257-1031 ng/mL) or 925 ng/mL (range: 62-2030 ng/mL), respectively. In pregnant HIV-infected women who received a regimen of nevirapine (200 mg once daily for 2 weeks followed by 200 mg twice daily), zidovudine, and lamivudine during the second and third trimester, cord blood concentrations (at delivery) and neonatal serum concentrations (24 hours after birth) of nevirapine were 76 and 60%, respectively, of maternal serum concentrations (at delivery). These neonatal concentrations were lower than those reported in neonates whose mothers received a single nevirapine dose during labor, possibly as the result of hepatic enzyme induction in the neonate after placental transfer.
Nevirapine is distributed into human milk. Following administration of a single 100- or 200-mg dose of nevirapine to pregnant women several hours before delivery, postpartum, concentrations of the drug in milk were 25-122% of maternal serum concentrations.

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Metabolism / Metabolites
Hepatic. In vivo studies in humans and in vitro studies with human liver microsomes have shown that nevirapine is extensively biotransformed via cytochrome P450 3A4 metabolism to several hydroxylated metabolites.
Oxidative metabolism of nevirapine in the liver by cytochrome p450 isoforms CYP34A4 and CYP2B6 produces several metabolites including 2-, 3-, 8-, and 12-hydroxynevirapine.
In vivo studies in humans and in vitro studies with human liver microsomes have shown that nevirapine is extensively biotransformed via cytochrome p450 oxidative metabolism to several hydroxylated metabolites. In vitro studies with human liver microsomes suggest that oxidative metabolism of nevirapine is mediated primarily by cytochrome p450 isozymes from the CYP3A family, although other isozymes may have a secondary role.
Nevirapine has known human metabolites that include 12-hydroxy-nevirapine, 2-Hydroxynevirapine, 8-Hydroxynevirapine, and 3-Hydroxynevirapine.

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Biological Half-Life
45 hours
Approximately 45 hours after a single dose, and 25 to 30 hours following multiple dosing with 200 to 400 mg per day.

Interactions
Caution is required when nevirapine is concurrently administered with a protease inhibitor, as the plasma concentrations of the protease inhibitors may be reduced to subtherapeutic concentrations due to increased hepatic metabolism by nevirapine.
Concurrent use of nevirapine with cimetidine may elevate steady-state nevirapine trough concentrations; dosage adjustment may be necessary.
The AUC values of /estrogen-containing/ oral contraceptives are reduced in the presence of nevirapine; therefore, oral contraceptives should not be used as the primary means of contraception when nevirapine is prescribed to women of childbearing potential.
Concurrent use /of ketoconazole/ with nevirapine results in significantly reduced plasma concentrations of ketoconazole and modest increase in plasma concentrations of nevirapine; concurrent use is not recommended.
For more Interactions (Complete) data for NEVIRAPINE (10 total), please visit the HSDB record page.

[1]. Characterization of the in vitro biotransformation of the HIV-1 reverse transcriptase inhibitornevirapine by human hepatic cytochromes P-450. Drug Metab Dispos. 1999 Dec;27(12):1488-95.

[2]. In vitro evaluation of the therapeutic potential of nevirapine in treatment of human thyroid anaplastic carcinoma. Mol Cell Endocrinol. 2013 May 6;370(1-2):113-8.

[3]. Inhibition of HIV-1 replication by a nonnucleoside reverse transcriptase inhibitor. Science. 1990 Dec 7;250(4986):1411-3.

[4]. Biotransformation of nevirapine, a non-nucleoside HIV-1 reverse transcriptase inhibitor, in mice, rats, rabbits, dogs, monkeys, and chimpanzees. Drug Metab Dispos. 1999 Dec;27(12):1434-47.

[5]. Evaluation of anti-ulcerogenic and ulcer-healing activities of nevirapine in rats. Afr J Med Med Sci. 2015 Sep;44(3):251-9.

Therapeutic Uses
Nevirapine is indicated, in combination with other antiretroviral agents, for the treatment of HIV-1 infection. Drug-resistant HIV emerges rapidly and uniformly when nevirapine is administered as monotherapy. Therefore, nevirapine should always be administered in combination with at least two other antiretroviral agents when it is used for the treatment of HIV-1 infection. /Included in US product labeling/
Nevirapine is indicated for the prevention of mother-to-child transmission of HIV-1 infection. /NOT included in US product labeling/
Nevirapine has been evaluated in pregnant HIV-infected women. In a landmark study performed in Uganda, a single, oral intrapartum dose of nevirapine followed by a single dose to the newborn was superior to more complicated zidovudine therapy in preventing vertical transmission. of HIV. Only 13% of nevirapine-treated women transmitted HIV compared to 21.5% of zidovudine-treated women.

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Drug Warnings
Severe, life-threatening, and in some cases fatal hepatotoxicity, including fulminant and cholestatic hepatitis (e.g., transaminase elevations with or without hyperbilirubinemia, prolonged partial thromboplastin time, or eosinophilia), hepatic necrosis, and hepatic failure, have been reported in patients receiving nevirapine. Although clinical presentation varied, frequently occurring features included nonspecific prodromal signs and symptoms of fatigue, malaise, anorexia, nausea, jaundice, liver tenderness, and/or hepatomegaly, with or without initially abnormal serum transaminase concentrations; a diagnosis of hepatotoxicity should be considered even if liver function tests are initially normal or alternative diagnoses are possible. Manifestations progressed over several days to hepatic failure with transaminase elevation, with or without hyperbilirubinemia, prolonged partial thromboplastin time, and/or eosinophilia. ... If nevirapine is discontinued because of hepatitis, it should be permanently discontinued and not reinitiated.
Hepatotoxicity has been also reported in a small number of individuals receiving nevirapine as part of a combination regimen for post-exposure prophylaxis of nosocomial or sexual HIV exposure.
Serious hepatotoxicity has been reported in individuals not infected with HIV who received multiple doses of nevirapine as part of a 2- or 3-drug regimen for postexposure prophylaxis following occupational or nonoccupational exposure to HIV. Adverse hepatic effects in these individuals have included end-stage liver failure requiring transplantation, clinical hepatitis (e.g., jaundice, fever, nausea, vomiting, abdominal pain, and/or hepatomegaly), and elevated serum ALT and AST concentrations without clinical hepatitis. ...
Severe and life-threatening skin reactions (e.g., Stevens-Johnson syndrome; toxic epidermal necrolysis; hypersensitivity reactions characterized by rash, constitutional findings, and organ dysfunction), including some fatalities, have occurred in patients receiving nevirapine. ...
For more Drug Warnings (Complete) data for NEVIRAPINE (15 total), please visit the HSDB record page.

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Pharmacodynamics
Nevirapine is a non-nucleoside reverse transcriptase inhibitor (nNRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). HIV-2 RT and eukaryotic DNA polymerases (such as human DNA polymerases alpha, beta, or sigma) are not inhibited by nevirapine. Nevirapine is, in general, only prescribed after the immune system has declined and infections have become evident. It is always taken with at least one other HIV medication such as Retrovir or Videx. The virus can develop resistance to nevirapine if the drug is taken alone, although even if used properly, nevirapine is effective for only a limited time.

C15H14N4O

266.3

266.116

129618-40-2

Nevirapine-d4;1051418-95-1;Nevirapine-d3;1051419-24-9

4463

White to off-white solid powder

1.4±0.1 g/cm3

415.4±45.0 °C at 760 mmHg

247°C

205.0±28.7 °C

0.0±1.0 mmHg at 25°C

1.672

2.03

1

4

1

20

397

0

NQDJXKOVJZTUJA-UHFFFAOYSA-N

InChI=1S/C15H14N4O/c1-9-6-8-17-14-12(9)18-15(20)11-3-2-7-16-13(11)19(14)10-4-5-10/h2-3,6-8,10H,4-5H2,1H3,(H,18,20)

11-cyclopropyl-4-methyl-5,11-dihydro-6H-dipyrido[3,2-b:2,3-e][1,4]diazepin-6-one

NSC 641530; BI-RG-587; BIRG 0587; BIRG587; HSDB 7164; Nevirapine; NSC 641530; NVP; trade name: Viramune; Viramune XR.

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 1.43 mg/mL (5.37 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 14.3 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 1.43 mg/mL (5.37 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 14.3 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)