Ritocom
Ritocom Uses, Dosage, Side Effects, Food Interaction and all others data.
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 is currently under investigation in combination with ritonavir for the treatment of COVID-19 caused by SARS-CoV-2.
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.
Ritonavir is an HIV protease inhibitor that interferes with the reproductive cycle of HIV. Although it was initially developed as an independent antiviral agent, it has been shown to possess advantageous properties in combination regimens with low-dose ritonavir and other protease inhibitors. It is now more commonly used as a booster of other protease inhibitors and is available in both liquid formulation and as capsules.
While ritonavir is not an active antiviral agent against hepatitis C virus (HCV) infection, it is added in combination therapies indicated for treatment of HCV infections as a booster. Ritonavir is a potent CYP3A inhibitor that increases peak and trough plasma drug concentrations of other protease inhibitors such as Paritaprevir and overall drug exposure. American Association for the Study of Liver Diseases (AASLD) and the Infectious Diseases Society of America (IDSA) guidelines recommend ritonavir-boosted combination therapies as a first-line therapy for HCV Genotype 1a/b and 4 treatment-naïve patients with or without cirrhosis.
Ritonavir is found in a fixed-dose combination product with Ombitasvir, Dasabuvir, and Paritaprevir as the FDA-approved product Viekira Pak. First approved in December 2014, Viekira Pak is indicated for the treatment of HCV genotype 1b without cirrhosis or with compensated cirrhosis, and when combined with Ribavirin for the treatment of HCV genotype 1a without cirrhosis or with compensated cirrhosis.
| Trade Name | Ritocom |
| Generic | Lopinavir + Ritonavir |
| Weight | 50mg, 200mg |
| Type | Tablet, Capsule |
| Therapeutic Class | Drugs for HIV / Anti-retroviral drugs |
| Manufacturer | Hetero Healthcare Limited, Genix, Hetero Labs Limited |
| Available Country | India, Nigeria |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Lopinavir and Ritonavir is an HIV-1 protease inhibitor used for combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients (14 days and older).
Pediatric Use: The safety, efficacy, and pharmacokinetic profiles of this combination in pediatric patients below the age of 14 days have not been established.
Ritocom is also used to associated treatment for these conditions: Human Immunodeficiency Virus Type 1 (HIV-1) InfectionHuman Immunodeficiency Virus (HIV) Infections
How Ritocom works
The HIV lifecycle is comprised of 3 distinct stages: assembly, involving creation and packaging of essential viral components; budding, wherein the viral particle crosses the host cell plasma membrane and forms a lipid envelope; and maturation, wherein the viral particle alters its structure and becomes infectious. At the center of this lifecycle is the Gag polyprotein which, along with the products of its proteolysis, coordinate these stages and function as the major structural proteins of the virus. The HIV-1 protease enzyme, a dimeric aspartic protease, is the enzyme responsible for cleaving the Gag polyprotein and thus plays a critical role in many aspects of the HIV viral lifecycle.
Lopinavir is an inhibitor of the HIV-1 protease enzyme. Its design is based on the "peptidomimetic" principle, wherein the molecule contains a hydroxyethylene scaffold which mimics the normal peptide linkage (cleaved by HIV protease) but which itself cannot be cleaved. By preventing HIV-1 protease activity, and thus the proteolysis of the Gag polyprotein, lopinavir results in the production of immature, non-infectious viral particles.
Ritonavic inhibits the HIV viral proteinase enzyme that normally cleaves the structural and replicative proteins that arise from major HIV genes, such as gag and pol. Gag encodes proteins involved in the core and the nucleocapsid, while pol encodes the the HIV reverse transcriptase, ribonuclease H, integrase, and protease . The pol-encoded proteins are initially translated in the form of a larger precursoe polypeptide, gag-pol, and needs to be cleaved by HIV protease to form other complement proteins . Ritonavir prevents the cleavage of the gag-pol polyprotein, which results in noninfectious, immature viral particles. Ritonavir is a potent inhibitor of cytochrome P450 CYP3A4 isoenzyme present both in the intestinal tract and liver . It is a type II ligand that perfectly fits into the CYP3A4 active site cavity and irreversibly binds to the heme iron via the thiazole nitrogen, which decreases the redox potential of the protein and precludes its reduction with the redox partner, cytochrome P450 reductase . Ritonavir may also play a role in limiting cellular transport and efflux of other protease inhibitors via the P-glycoprotein and MRP efflux channels .
Dosage
Ritocom dosage
Lopinavir and Ritonavir tablets may be taken with or without food, swallowed whole and not chewed, broken, or crushed.
Adult Patients:
- 400/100 mg (two 200/50 mg tablets) twice daily, or
- 800/200 mg (four 200/50 mg tablets) once daily in patients with less than three lopinavir resistance-associated substitutions.
Do not use once daily administration of Lopinavir and Ritonavir in: HIV-1 infected patients with three or more of the following lopinavir resistance-associated substitutions: L10F/I/R/V, K20M/N/R, L24I, L33F, M36I, I47V, G48V, I54L/T/V, V82A/C/F/S/T, and I84V. Combination with efavirenz, nevirapine, nelfinavir, carbamazepine, phenobarbital, or phenytoin.
Side Effects
Commonly reported side effects included diarrhea, nausea, vomiting, hypertriglyceridemia and hypercholesterolemia.
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.
Human experience of acute overdose with ritonavir is limited. One patient in clinical trials took ritonavir 1500 mg/day for two days. The patient reported paresthesias which resolved after the dose was decreased. A post-marketing case of renal failure with eosinophilia has been reported with ritonavir overdose. The approximate lethal dose was found to be greater than 20 times the related human dose in rats and 10 times the related human dose in mice. Oral LD value in rats is >2500 mg/kg. Adverse effects of ritonavir may arise from drug-drug interactions. Other effects include hepatotoxicity, pancreatitis, and allergic reactions/hypersensitivity.
Precaution
The following have been observed in patients receiving Lopinavir and Ritonavir:
Hepatotoxicity: Patients with underlying hepatitis B or C or marked elevations in transaminase prior to treatment may be at increased risk for developing or worsening of transaminase elevations or hepatic decompensation with use of this combination.
QT Interval Prolongation: In cases of QT interval prolongation and torsade de pointes have been reported although causality of this combination could not be established. Avoid use in patients with congenital long QT syndrome, those with hypokalemia, and with other drugs that prolong the QT interval.
PR Interval Prolongation: Lopinavir/ritonavir prolongs the PR interval in some patients. Cases of second or third degree atrioventricular block have been reported. This combination should be used with caution in patients with underlying structural heart disease, pre-existing conduction system abnormalities, ischemic heart disease or cardiomyopathies, as these patients may be at increased risk for developing cardiac conduction abnormalities.
Diabetes Mellitus/Hyperglycemia: New onset diabetes mellitus, exacerbation of pre-existing diabetes mellitus, and hyperglycemia have been reported in HIV-1 infected patients receiving protease inhibitor therapy. Some patients required either initiation or dose adjustments of insulin or oral hypoglycemic agents for treatment of these events. In some cases, diabetic ketoacidosis has occurred. In those patients who discontinued protease inhibitor therapy, hyperglycemia persisted in some cases.
Lipid Elevations: Treatment with Lopinavir and Ritonavir has resulted in large increases in the concentration of total cholesterol and triglycerides.
Interaction
Co-administration of Lopinavir and Ritonavir is contraindicated with potent CYP3A inducers where significantly reduced lopinavir plasma concentrations may be associated with the potential for loss of virologic response and possible resistance and cross resistance. It is also contraindicated with Alpha 1 Adrenoreceptor Antagonist (Alfuzosin), Antimycobacterial (Rifampin), Ergot Derivatives ( Dihydroergotamine, ergotamine, methylergonovine), Gl Motility Agent (Cisapride), HMG-CoA Reductase Inhibitors (Lovastatin, simvastatin), PDE5 Enzyme Inhibitor (Sildenafil, when used for the treatment of pulmonary arterial hypertension), Neuroleptic (Pimozide) Sedative/Hypnotics (Triazolam; orally administered midazolam)
Volume of Distribution
The volume of distribution of lopinavir following oral administration is approximately 16.9 L.
The estimated volume of distribution of ritonavir is 0.41 ± 0.25 L/kg.
Elimination Route
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%).
The absolute bioavailability of ritonavir has not been determined. Following oral administration, peak concentrations are reached after approximately 2 hours and 4 hours (Tmax) after dosing under fasting and non-fasting conditions, respectively. It should be noted that ritonavir capsules and tablets are not considered bioequivalent.
Half Life
The elimination half-life of lopinavir is 6.9 ± 2.2 hours.
The approximate half-life of ritonavir is 3-5 hours.
Clearance
The estimated apparent clearance following oral administration is approximately 6-7 L/h.
The apparent oral clearance at steady-state is 8.8 ± 3.2 L/h. Renal clearance is minimal and estimated to be 7
Elimination Route
Lopinavir is primarily eliminated in the feces. Following oral administration, approximately 10.4 ± 2.3% of the administered dose is excreted in the urine and 82.6 ± 2.5% is excreted in the feces. Unchanged parent drug accounted for 2.2% and 19.8% of the administered dose in urine and feces, respectively.
Ritonavir is primarily eliminated in the feces. Following oral administration of a single 600mg dose of radiolabeled ritonavir, approximately 11.3 ± 2.8% of the dose was excreted into the urine, of which 3.5 ± 1.8% was unchanged parent drug. The same study found that 86.4 ± 2.9% of the dose was excreted in the feces, of which 33.8 ± 10.8% was unchanged parent drug.
Pregnancy & Breastfeeding use
Nursing Mothers: The Centers for Disease Control and Prevention recommend that HIV-1 infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV-1. Studies in rats have demonstrated that lopinavir is secreted in milk. It is not known whether lopinavir is secreted in human milk. Because of both the potential for HIV-1 transmission and the potential for serious adverse reactions in nursing infants, mothers should be instructed not to breastfeed if they are receiving this combination
Contraindication
Lopinavir and Ritonavir is contraindicated in patients with previously demonstrated clinically significant hypersensitivity (e.g., toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme, urticaria, angioedema) to any of its ingredients, including lopinavir and ritonavir.
Co-administration of Lopinavir and Ritonavir is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening reactions.
Acute Overdose
Human experience of acute overdosage with this combination is limited. Treatment of overdose should consist of general supportive measures including monitoring of vital signs and observation of the clinical status of the patient. There is no specific antidote for overdose with this combination. If indicated, elimination of unabsorbed drug should be achieved by gastric lavage. Administration of activated charcoal may also be used to aid in removal of unabsorbed drug. Since lopinavir is highly protein bound, dialysis is unlikely to be beneficial in significant removal of the drug. However, dialysis can remove both alcohol and propylene glycol in the case of overdose with this combination.
Storage Condition
Keep in a dry place & store below 30° C. Protect from light & keep out of the reach of children.
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