Lopinavir

Absorption

When administered alone, lopinavir has exceptionally low oral bioavailability (~25%) - for this reason, it is exclusively co-administered with ritonavir, which dramatically improves bioavailability, hinders drug metabolism, and allows for the attainment of therapeutic lopinavir concentrations. Following oral administration of lopinavir/ritonavir, maximal plasma concentrations are achieved at approximately 4.4 hours (Tmax), and the Cmax and AUCtau are 9.8 ± 3.7 - 11.8 ± 3.7 μg/mL and 92.6 ± 36.7 - 154.1 ± 61.4 μg?h/mL, respectively.
Relative to administration in the fasted state, administration with a meal increases the AUC of the tablet formulation slightly (~19%) but dramatically increases the AUC of the oral solution formulation (~130%).

Toxicity

As lopinavir is only available in combination with ritonavir, experience with acute lopinavir overdose in isolation is limited. The risk related to overdose appears more pronounced in pediatric patients. One case report detailed a fatal cardiogenic shock in a 2.1kg infant following an approximately 10-fold overdose of Kaletra oral solution, while other reported reactions to overdose in infants include complete AV block, cardiomyopathy, lactic acidosis, and acute renal failure. The oral Kaletra solution is highly concentrated, posing a greater risk of overdose, and contains approximately 42% (v/v) ethanol, further increasing risk in children and infants.
There is no antidote for lopinavir overdose. Treatment of overdose should consist largely of supportive measures and close observation of vital signs and clinical status of the affected patient. Consideration should be given to the removal of unabsorbed drug using gastric lavage or activated charcoal, if clinically indicated. Dialysis is unlikely to be of benefit as lopinavir is highly protein-bound, but may help to remove ethanol and propylene glycol from the circulation in the case of overdose with Kaletra oral solution.

Description

Lopinavir, the sixth HIV protease inhibitor in the “navir” class, was launched in coformulation with ritonavir, another HIV protease inhibitor already marketed (Abbott, 1996); this original formulation was introduced as Kaletra for use in combination with either nucleoside or non-nucleoside reverse transcriptase inhibitors for the treatment of AIDS in adults and children. Lopinavir is a peptidomimetic compound with a structural core identical to that of ritonavir, on which terminal groups, particularly a modified valine, were introduced by peptide coupling procedures. Lopinavir is a potent competitive inhibitor of HIV-I protease exhibiting high potential against ritonavir-resistant mutations. In several animal species, pharmacokinetic studies with the lopinavirlritonavir association showed that the modest properties of lopinavir were significantly improved in presence of ritonavir, in terms of Cmax and duration of action. Ritonavir inhibits the P450 isoenzyme CYP3A4 and the human liver microsomal metabolism of lopinavir, so strongly amplifying plasma levels of this latter component. In AIDS patients, the plasma HIV RNA level was considerably reduced and the CD4+ T-cell counts increased after administration of lopinavir combined with relatively small doses of ritonavir. Kaletra is intended to be used jointly with other antiretroviral agents.

Chemical properties

Lopinavir is a white to light tan powder. It is freely soluble in methanol and ethanol, soluble in isopropanol and practically insoluble in water.

Originator

Abbott (US)

The Uses of Lopinavir

Lopinavir is a potent HIV protease inhibitor with Ki of 1.3 pM

The Uses of Lopinavir

A selective HIV protease inhibitor. An analogue of Ritonavir. Antiviral.

The Uses of Lopinavir

Lopinavir has been used as a ZMPSTE24 and human immunodeficiency virus protease inhibitor.

Indications

The combination product lopinavir/ritonavir, marketed under the brand name Kaletra, is indicated in combination with other antiretrovirals for the treatment of HIV-1 infection in adults and pediatric patients ≥14 days old.

Background

Lopinavir is an antiretroviral protease inhibitor used in combination with other antiretrovirals in the treatment of HIV-1 infection. Lopinavir is marketed and administered exclusively in combination with ritonavir - this combination, first marketed by Abbott under the brand name Kaletra in 2000, is necessary due to lopinavir's poor oral bioavailability and extensive biotransformation. Ritonavir is a potent inhibitor of the enzymes responsible for lopinavir metabolism, and its co-administration "boosts" lopinavir exposure and improves antiviral activity. Like many other protease inhibitors (e.g. saquinavir, nelfinavir), lopinavir is a peptidomimetic molecule - it contains a hydroxyethylene scaffold that mimics the peptide linkage typically targeted by the HIV-1 protease enzyme but which itself cannot be cleaved, thus preventing the activity of the HIV-1 protease.
Lopinavir was previously under investigation in combination with ritonavir for the treatment of COVID-19 caused by SARS-CoV-2.

What are the applications of Application

Lopinavir is an HIV-1 protease inhibitor

Definition

ChEBI: Lopinavir is a dicarboxylic acid diamide that is amphetamine is substituted on nitrogen by a (2,6-dimethylphenoxy)acetyl group and on the carbon alpha- to nitrogen by a (1S,3S)-1-hydroxy-3-{[(2S)-3-methyl-2-(2-oxotetrahydropyrimidin-1-yl)butanoyl]amino}-4-phenylbutyl group. An antiretroviral of the protease inhibitor class, it is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir. It has a role as an antiviral drug, a HIV protease inhibitor and an anticoronaviral agent. It is a member of amphetamines and a dicarboxylic acid diamide.

Indications

Lopinavir is available in the United States only as a fixed-dose combination with ritonavir (Kaletra). In this regimen, a low dose of ritonavir is used to inhibit the rapid inactivation of lopinavir by CYP3A4.

Manufacturing Process

Manufacturing process for Lopinavir includes these steps as follows: Synthesis of 2,6-dimethylphenoxyacetic acid; 2,6- dimethylphenoxyacetyl chloride as an oil; synthesis of (2S,3S,5S)-2-(2,6-dimethylphenoxyacetyl)amino-3-hydroxy-5-(tbutyloxycarbonylamino)-1,6-diphenylhexane; (2S,3S,5S)-2-(2,6-dimethylphenoxyacetyl)amino-3-hydroxy-5- amino-1,6-diphenylhexane as a white needles; synthesis of N-carbonylbenzyloxy-3- aminopropanol;synthesis of N-carbonylbenzyloxy-3-aminopropanal solution; N-(N- (benzyloxycarbonyl-3-amino)-propyl)valine methyl ester, oil state; synthesis of 2S-(1-tetrahydro-pyrimid-2-onyl)-3- methyl butanoic acid methyl ester;synthesis of 2S-(1- tetrahydro-pyrimid-2-onyl)-3-methyl butanoic acid methyl ester. The mixture of (2S,3S,5S)-2-(2,6-dimethylphenoxyacetyl)amino-3-hydroxy-5- amino-1,6-diphenylhexane (100 g, 0.22 mol), 2S-(1-tetrahydro-pyrimid-2- onyl)-3-methyl butanoic acid methyl ester (44.8 g, 0.22 mol) and 750 ml DMF was cooled in an ice/water bath. N-Hydroxybenzotriazole (90.9 g, 0.67 mol), 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (86 g, 0.45 mol) and triethylamine (62.5 ml, 0.45 mol) were added and the ice bath was removed, allowing the reaction mixture to stir with warming to room temperature for 5 hours. The mixture was diluted with 1000 ml of IPAC and quenched with 1000 ml of water. The mixture was shaken and separated, the aq. layer was extracted IPAC, the organics were washed with 10% HCl, solution of NaHCO3 with 100 ml hexanes, then washed 500 ml water, and brine, dried over MgSO4, filtered and concentrated to provide. (2S,3S,5S)-2-(2,6- dimethylphenoxyacetyl)amino-3-hydroxy-5-(2S-(1-tetrahydro-pyrimid-2-onyl)- 3-methylbutanoyl)amino-1,6-diphenylhexane as a white foam.

brand name

Kaletra

Therapeutic Function

Antiviral

Antimicrobial activity

Lopinavir is active against HIV-1 and HIV-2.

Acquired resistance

Significant resistance to the antiretroviral efficacy of ritonavirbooted lopinavir occurs as a result of amino acid substitutions at positions 32, 47 and 82 in the protease region. Protease inhibitor resistance is uncommon in patients identified with early failure of combination therapy with ritonavir boostedlopinavir and nucleotide reverse transcriptase inhibitors.

General Description

Lopinavir is a protease inhibitor that has been approved foruse in combination with ritonavir for patients with HIV whohave not responded to other treatment modalities. Lopinaviris used in excess over ritonavir. Ritonavir at amounts givenhas no antiretroviral activity, Ritonavir inhibits lopinavir’smetabolism by CYP3A4, causing a higher level of lopinavirin the system. The combination is the first protease inhibitorapproved for patients as young as 6 months of age.

Biochem/physiol Actions

Lopinavir is an antiviral HIV Protease Inhibitor. Lopinavir has insufficient bioavailability alone, so it is used in therapy in combination with Ritonavir, a HIV protease inhibitor, which inhibits cytochrome P450-3A4 (CYP3A4), a liver enzyme that normally metabolizes protease inhibitors. Lopinavir also has an ability to inhibit ZMPSTE24 (zinc metallopeptidase STE24).

Pharmacokinetics

Lopinavir inhibits the activity of an enzyme critical for the HIV viral lifecycle. It has a moderate duration of action necessitating once or twice daily dosing. Lopinavir, like other protease inhibitors, has a propensity for participating in drug interactions - use caution when administering lopinavir to patients maintained on other pharmaceutical agents as pharmacodynamic and pharmacokinetic interactions are common. Fatal hepatotoxicity and pancreatitis have been noted in patients undergoing therapy with lopinavir and patients with an increased baseline risk of these events should be monitored closely throughout therapy.

Pharmacokinetics

Oral absorption: Not known/available
C_max 400 mg + ritonavir 100 mg twice daily: c. 9.6 mg/L
C_min 400 mg + ritonavir 100 mg twice daily: c. 5.5 mg/L
Plasma half-life: c. 5–6 h
Volume of distribution: Not known/available
Plasma protein binding: c. 98–99%
Absorption and distribution
The absorption of lopinavir–ritonavir in capsule or liquid form is favorably affected by the presence of food, particularly if high in fat. The CNS penetration is good. It has a semen:plasma ratio of 0.07. It is distributed into breast milk.
Metabolism
Lopinavir is extensively metabolized by the CYP3A4 system, but this is inhibited by ritonavir.
Excretion
Over an 8-day period after single dosing with the combined formulation, around 10% and 83% of the administered dose is recovered in urine and feces, respectively. Less than 3% of the dose is recovered as unchanged drug in urine and 20% in feces. In mild to moderate hepatic impairment, an increase in exposure of approximately 30% is observed, but is probably not clinically relevant. It should be avoided in severe hepatic impairment.

Clinical Use

Treatment of HIV infection (in combination with ritonavir and other antiretroviral agents)

Side Effects

The most common adverse events seen in trials of complex antiretroviral regimens were diarrhea, nausea, headache, fatigue, vomiting and rash. Ritonavir-boosted lopinavir is associated with a dyslipidemia profile characteristic of those treated with other protease inhibitors boosted with 200 mg of ritonavir.

Metabolism

Lopinavir undergoes extensive oxidative metabolism, almost exclusively via hepatic CYP3A isozymes. Co-administration with ritonavir, a potent inhibitor of CYP3A enzymes, helps to stave off lopinavir's biotransformation and increase plasma levels of active antiviral drug. Twelve metabolites have been identified in vitro, with the C-4 oxidation products M1, M3, and M4 being the predominant metabolites found in plasma. The structures of these primary metabolites have been identified, but precise structural information regarding the remaining minor metabolites has not been elucidated.

storage

-20°C